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GEOL7323 Borehole Geophysics - Day4 02-25-2023 PM
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00:05 Hey Stephanie, how you doing? , good, good. How was
00:10 ? Starbucks coffee. It was delicious I needed it. Yeah, I've
00:16 it I've got a cup here. a Starbucks coffee, but Homebrew,
00:24 . The classic french roast. I my favorite homebrew is the, I
00:31 the Htv Castella coffees. Oh, so good. Oh, which kind
00:36 a TB? Yeah, it's the E B. They have their own
00:40 of coffee. It's think it's casa and they are delicious. Uh you
00:51 , almost any coffee is okay, I've grown accustomed to, the french
00:57 pretty, it's pretty um distinctive or roasted. Some people might call it
01:04 little better, but um that's kind the Starbucks taste I bet.
01:12 the casa ole, they have a rose to its, I think my
01:15 , my top three is the san , the french roast and then they
01:21 a texas, pecan, those are my top three favorite ones.
01:25 I'll have to try that. Maybe a chance to pick some up today
01:28 tomorrow, highly recommend a good Hmm. Yeah, we went
01:36 there's something in, in Colombia called , the, which is the,
01:45 the coffee, the coffee route, can, you can go around and
01:50 to all the plantations. Really you know, I don't know if
01:53 like an avid coffee drinker, but christmas, a couple years ago I
01:58 my sister a subscription. It's called coffee company. And every month they
02:05 you a coffee from a different It would be like a nicaraguan
02:09 a Colombian coffee african, whatever. and it's it was some of the
02:16 coffee that we've ever had. Like was from Guatemala, from Mexico is
02:19 Costa rica, it's everywhere. And month they send you a new
02:25 That's a great idea. Mhm. . Nice, nice gift. I've
02:30 some of them that are kind of , they're sort of care packages with
02:35 of gourmet spreads and meats and stuff that, which are which are
02:42 But I think the copy is a idea because you can store it maybe
02:46 little bit better. And there's probably bad copy that they would send.
02:54 know, I think our favorite was mexican. Like it was, it
02:57 like this chocolate essence to it. it was just and then you get
03:01 postcard with every country that they send , they send you like a postcard
03:06 a postcard from like the village or that like harvested. Oh cool.
03:11 that's another one of those fantasies would great to have a little coffee plantation
03:16 with fruit trees and mango trees and good would that be? Yeah,
03:22 mexican copy too, sometimes has cinnamon it, which I really like that
03:30 . Well. Well, well, dream of coffee uh in the
03:34 let's I'm sure there is a type log that could be applied to coffee
03:39 , but we'll have to figure that . Great. Well, I I
03:45 up this little guy um here is a suite of logs in the gulf
03:52 Mexico. And just for practice we have a look at these guys
03:59 Um interval C. Is perhaps the interesting. And so if you were
04:08 scan through this you can see that highlighted a few layers of interest.
04:16 Now once again if you go through um how did we how did we
04:24 of pick our layers of interest? looking at the gana log, those
04:33 are really the only ones that have a significant or C. Is the
04:38 like significant one. I mean there's stuff in between B. And
04:42 But when you go through all of , A B. And C.
04:46 the only ones like especially the Itty log, those are really the
04:52 three that like jump out at you then even the density log and
05:03 Oops that's what I meant to Um Well let's walk, let's walk
05:15 layer. See, tell me about C. Okay um layer C.
05:22 so for gamma it's low gamma. I put the scales on the
05:27 Yeah because that person is like I read this and I'm like yeah I
05:31 neither can I. Um So gamma have low gamma. So it's not
05:37 . Um V. P. Nothing crazy what's going on and see um
05:48 . S. We do have an . So that would be a lower
05:56 time. Yes. Okay so we slower transit. So maybe so less
06:05 is less rigid. Lower transit. transit. Oh so that's faster so
06:13 more. Okay, so. so we maybe have a sand.
06:22 , we have high resistive Itty. that goes along with the sand.
06:33 it may or may not. That's , we like it when it does
06:40 usually wouldn't. Okay, so very resistive. Itty. Well, keep
06:51 there for a minute. Um Going the density we have a decrease in
07:05 and our scale is from 1.5 to . So if that 1.5 to
07:24 do I have to? So 0.75 about in the middle. So density
07:29 going to be less than that No, what's the scale? Hold
07:44 , it's 1.5 to 3 two So we have a low density
07:54 Um So going to the next log do have, let's see which one's
08:07 black one? Is that gonna be I'm assuming the red one is the
08:16 . Uh No, the little So density porosity. Okay, so
08:25 see we do have a crossover. , so the again this is why
08:31 of the reason for this exercise is of the logs are plotted the opposite
08:36 . So you have to be alert this case the porosity is zero on
08:42 left, 50% on the right and it's then the density porosity is in
08:57 . So this is about 25 so about 30 to 40% porosity.
09:09 there there are the there are the curves. Yeah, and there's a
09:15 . Really strong crossover and to the is low porosity. So the black
09:24 is the neutron ferocity and the the curve is making an excursion to low
09:38 . Oh, okay, Okay. then that would not be, what
09:46 said was the middle of the So that would be like zero.
09:54 I don't know, maybe like 15 20. Well, I would say
10:01 average is around 25. I think that's about right. But because word
10:11 can see here, the next curve is the their calculation of the
10:19 And so you can see what their is. The next the next curve
10:28 red. 11 to 39. Okay, so it's basically going 10
10:34 40 and they're saying it's halfway in and 10 to 40 halfway is
10:44 So yeah, pushing 30 30% And when they say effective ferocity,
10:52 the flowing ferocity, right? So they've done a they've done a
10:58 calculation to try to get rid of some of the clay effects in
11:08 So that's a little bit less than total ferocity. Okay, and then
11:19 w so that's gonna be this Yeah, and it goes from 0
11:28 1. So this is not very with brian. Right, well,
11:41 , yeah, so let's go through now now, you've you've been through
11:45 . So so that's the logic process you're doing this all the time.
11:49 giving you practice to kind of, through all these steps. Um You've
11:53 through it, you've looked at what values are, we haven't really said
11:59 what's going on yet, but now been through all this, so what's
12:03 on and by what's going on? mean what kind of rock is
12:07 What kind of process does it What kind of permeability and likely what's
12:12 saturation? Um I think we'll throw off. Is we have a
12:23 But the p wave velocity didn't really much. So that takes me away
12:29 gas and pushes me to oil. oil wouldn't have that crossover, would
12:36 ? Well, that crossover is really strong. Yeah, So that
12:40 be gas. Yeah. And the . It e is very well developed
12:47 the density drops a lot. So here's here's what I would I
13:05 think about that when you look at shear wave velocity, the shear wave
13:10 has jumped a lot, it's getting lot faster. Cbs it's getting a
13:17 faster. So in principle that rigidity part of the p wave velocity to
13:26 principle, the p wave should be just the lift ology should increase the
13:32 wave velocity. Remember that the p velocity is dependent on the bulk
13:39 Like we talked about K. Or , but it's also dependent on the
13:44 . So we've said that the shear velocity is strictly dependent on the rigidity
13:51 the numerator. Okay, so the say that the rock is really getting
14:00 for the sheer wave. It should getting fast with faster with the P
14:06 too. But as you pointed it's not so in a sense,
14:17 P wave velocity is decreasing a bunch where. So there's something that's suppressing
14:24 P wave response and the big thing lowers the p wave velocity is
14:32 Okay, that makes sense. I just dampening the effect of the
14:36 so if this were fluid saturated, shear wave velocity would be about the
14:40 . You'd see a big kick in P wave velocity and it would all
14:47 perfect sense that way too. But we stand right now, we've got
14:51 gamma ray as low so that this in the gulf coast. So we
14:58 that it's largely sad shell. Um that's one thing, we don't see
15:05 in the P wave velocity. So first we just don't know anything about
15:08 . I look at the sheer it's it's increasing. So that tells
15:12 it's probably sad then the resistive. is huge. So that says I've
15:17 got hydrocarbons or it's tight. There's porosity. So that I go over
15:24 I checked the process and it says , no, no, no,
15:26 , no, there's there's lots of . And then they say, oh
15:33 , the resistive, it has to because of hydrocarbons then. And then
15:38 look at the porosity logs and I , wow, there's a huge slam
15:42 crossover in the porosity logs. So gas. And then we go back
15:48 check the density and sure enough, density log has decreased a lot.
15:53 I said, whoa, that's gas . And then I go back and
15:57 at the p wave log, I , oh, you know what?
16:00 should be an increase. But the is knocking the p wave velocity
16:06 So that all makes sense. And when we look at the saturation,
16:14 saturation of water is just about zero . So we're looking at something like
16:21 gas saturation. Mhm. What's TPP for? Oh, where, where
16:32 that? Oh, okay. Well I was doing that was calibrating this
16:41 seismic reflection time to so that's the wave reflection time down to that
16:49 So the I don't whether I think log is actually not plotted in
16:56 I think it's actually plotted in p reflection time. Okay, so you
17:05 , the the logs themselves are our depth. That's how we've done the
17:11 but we're gonna move on to um seismic grams. And as you know
17:20 seismic response, we get a We get an echo in time.
17:23 in depth. So the seismic the seismic volume is in time not
17:31 . So one of the first things we're gonna do is we convert the
17:37 and depth two logs in time in time. And so that's a big
17:51 . We'll probably talk about that in an hour. Okay so it's very
17:59 that we because we're exploration geophysicists and main measurement is seismic and the basic
18:12 measurement is echoes in time. So need to we need to bring all
18:23 our logs into the seismic realm. to do that we have to convert
18:29 logs that are actually in depth to log that would be seen by echoes
18:35 the echoes are in time. So need a velocity to convert the logs
18:39 depth to what they would look like time. And that's been done
18:44 So these logs are actually in seismic time which is proportional to doubt.
18:58 . Okay. And you can see couple of other little horizons here.
19:06 a just quickly what do you think a the interval A. Um.
19:19 so for a we have again below Vp nothing special ves slighty greatest like
19:39 slight um It's just like increase in . Getting faster. Yeah so it's
19:46 in transit time. So it's getting . And then the receptivity. It's
19:56 low resistive. E. Or high . Sorry, um density. We
20:02 have a slight decrease. We don't a crossover. So this would be
20:13 think we have maybe a very small . Well, remember these? Uh
20:29 . Okay. And so sorry, porosity again going on. Oh
20:34 um porosity, we have an So that's going to be about what
20:46 my scallion Colin mm. Atrocity is let's see if that one down there
20:57 about 25. So maybe about 10 . No. So is the scale
21:08 11 to 39? Or is it ? Yeah, is from 11 to
21:12 . So then that would be about see L 2 39. Mhm.
21:27 be about 14 in the middle. maybe about well, 12 or so
21:39 the porosity. Well, it's the between 10 and 40 in the
21:51 Oh see I always I forget to at the tip. I was looking
21:55 like the where the red isn't. yeah, never mind. I'm
22:01 Yeah. So it's just we're in the middle from 10 to 40.
22:06 around 20. Around 25%. 25% is the same as the other
22:14 Yeah, a little bit less. but in the game. So I
22:20 you're right that if we look at W the saturation of water. Mm
22:32 . A little less than 50. . So among friends say 50%.
22:41 it's 50% saturated with water. What's other 50% again, hydrocarbon?
22:53 Uh we do see a little kick the density and this one's a little
23:06 trickier. I I think it's this is just the density, the
23:17 porosity, czar may be shifted a bit. This is a little bit
23:26 , but I'd be inclined to think this is kind of mixed. There's
23:32 oil and gas in it in There's often um, a mix and
23:40 it can be called what's called fizz , just low concentrations of gas.
23:46 so the it's because this whole, whole area is a little bit
24:01 You can see that if we look the gamma ray, let's go back
24:05 the gamma ray. Even what we sands. What, what's the value
24:11 the gamma ray there? Let's It goes from 0 to 150.
24:19 would be 75. So it's And some change or mine has
24:28 Yeah, 60 ish on the gamma now. Is that a, is
24:31 a pure sand? Mm No, really. It's it's still a bit
24:40 . So even what we're calling reservoir is probably a little bit dirty.
24:45 some there's some shale in there. this whole section is kind of kind
24:50 dirty and that's that's causing the ferocity to be somewhat separated. So I
25:06 that it's not as definitive. Obviously the sea is just an incredible slam
25:12 of a gas reservoir a is not obvious what it is. It looks
25:19 bit oily, but some of the suggest there's a little bit of gas
25:23 there too. So that, that gets a bit more complicated and we
25:27 want to look at some other logs then we would do some modeling and
25:32 probably have the gas chromatograph when we through there. Were there any gas
25:36 , oil shows? So we, want to be looking at some other
25:40 that kind of nail that one That's a little that layer and it's
25:46 thin layer too. So it's just little bit, that one's a little
25:50 to interpret the a layer. But be going with, we like
25:59 it's thin, it might be worth to produce. It's probably oil with
26:05 gas. The other reservoir deeper. might be the, that might be
26:12 really good, a really good Okay. Any, any questions about
26:19 one? It's starting to get Let's look at, let's look at
26:25 other other logs. Incidentally, this is just north of Montana. So
26:29 worked in this area for a Um, it was interesting. We
26:37 , we flew into an oil field it was, it was out in
26:42 middle of nowhere and we landed the and the pilot took off, but
26:46 was, it was totally an abandoned and it turned out that it was
26:50 the Second World war. They trained lot of pilots flying here because it's
26:53 flat land and really good flying but nobody there. So what do we
26:59 now? So we we called, called the oil field operator and he
27:04 oh there's a big old cadillac and of the sheds, the keys are
27:08 it. Just go over to the and jumping this big old cadillac and
27:14 probably get oil field. So that's we did. Absolutely nobody in this
27:20 big airport. So we made it kind of like a movie. Um
27:28 here's here's the play. So this this is pretty busy but here's where
27:33 were working. And once again we've we know a little bit about the
27:38 . We're we're looking in various we know that the areas are
27:47 So here's what you get as your geologic column is going to have the
27:53 units, their ages and conformity And then the the intervals that are
28:00 to be petroliferos or that are known be hydrocarbon bearing. So we're going
28:05 be alert to be looking at the and the what was the cantar?
28:12 these are probably the cretaceous is maybe second biggest oil deposit time in North
28:23 . So we do our regular We look for the the S.
28:30 . So I'm scanning down the P. No no, no,
28:35 . Something interesting in here and then jump over the gamma ray. Uh
28:45 . Jump over the gamma ray and down maybe very Shelly. No no
28:54 no. Okay I like that. gamma rays there uh ferocity we're looking
29:07 again. So the neutron ferocity scanning here and then we go over to
29:14 money, log the resistive itty and down and I see a couple of
29:23 that have nice resistive excursions at the here. So that's looking interesting.
29:35 now let's look at smart detail and you can tell me all about
29:43 So can you walk, can you us through the logs here? Unfortunately
29:49 slightly annotated for you and they're not crowded. Okay so on the
29:57 P. Log we have that pretty section right there. Low sp so
30:06 . So it's a pretty big vulnerable . Um Then gamma ray, if
30:15 jump across one gamma we have so we hit that section we have low
30:24 through that whole area. So it's shale, not shale. And then
30:37 into the ferocity um Nothing crazy at top of the section. They're in
30:51 middle and then we have a pretty . Hello there in that dotted section
31:00 that dash section. Um And then goes back to the middle and then
31:06 goes low again. So we have sections of that. Hello, is
31:12 low prostate? It's increasing to the . Yeah, so Prasit e increases
31:18 the right in this case. So two sections we have low porosity and
31:24 it increases their at the top in middle. So this is an area
31:34 what kind of ferocity um Would that considered high porosity or like mid
31:44 Well it's pretty high, this goes , it's hard to see, this
31:47 from 0 to 60%. So this around 30 31 or 32% porosity.
31:54 that's pretty high porosity. I always want to call it like I know
32:00 mid isn't the thing that I want say because it's like in the middle
32:02 the chart, but it's relative what scale is. Yeah, you always
32:06 to look at the scale because it's the middle of the chart, but
32:11 30% porosity. So that's I I mean if I only plotted up
32:17 30% it would be right on the wouldn't be in the middle anymore.
32:24 , so it's high porosity. Something weird happens here though, it
32:32 very low, like almost zero so there's a baffle in there,
32:41 a there's a low zero porosity. The sp log isn't really seeing
32:52 so it might have some permeability but actually not very much. So then
33:09 sonic logs show it's hard to see the units here, but presumably this
33:27 fast to the left and so we're , we've got the Shelly stuff here
33:34 relatively slow and then we're get we faster, you can see the P
33:39 doesn't do much, but the but sheer waves getting faster once again,
33:44 our good sand indicator. And then gets very fast in here, which
33:51 that it's completely cemented, zero ferocity cemented. So it's like a tight
34:03 . Okay. And then um going to our resistive Itty, we see
34:14 classic again that high resistive itty on of the rez activity tracks again the
34:25 the shallow is the highest which you'd , but the other ones are pretty
34:30 um and then we go into very low resistive Itty. So this
34:35 our classic hydrocarbon oil over water Just so you don't think that these
34:51 just odd ones. Here's another one you. So we'll just step through
35:02 to make sure because sometimes people find logs for different purposes and you can
35:07 here, do you know what the this yellow key is pretty standard with
35:14 with the dots in it, dots sand, aren't they? Yeah,
35:20 yellow dot yellow with dots that's typically . Um This is typically limestone.
35:32 . Okay, so as we now are partially interpreted logs for us
35:37 Somebody's done most of our work for but the this is supposed to be
35:44 largely sandstone interval. Mhm. And so we can see the volume
35:57 shale going from 0 to 100%. it's again, what we say is
36:08 massive sandstone and it's clearly not really massive sandstone, this is something like
36:14 couple million years of deposition, so not quite that simple. Some parts
36:20 very sandy, so that's all Those sandy parts have a high effective
36:30 , you can see up to around 34%. So that's very good
36:37 S w the saturation of water is down to maybe 10 or 20%.
36:44 that means that all the rest of stuff is hydrocarbon and we see a
36:49 drop in the hydrocarbon a little bit . P and Bs don't show very
36:54 and this happens to be all heavy . So the saturation of water is
37:04 10 or 20%. Um All of Phil is all oil and that's um
37:15 like 100 ft of oil. So also very intense. Mhm.
37:42 Now we we can push this all bit farther. We've talked about densities
37:47 velocities and what people often do is plot those again to figure out more
37:53 mythology and this was fabulous Ruiz. was one of our master students,
37:58 probably did, you did, you Fabiola, her name sounds very familiar
38:04 I can't put face to name, graduated a few years ago and then
38:12 went to work with E. G. In Fort Worth. So
38:20 actually did her masters on the marcellus and did a good job and I
38:27 looking around for a job. So she uh it turned out that the
38:33 . G. Was going to start in the Marcellus. So they were
38:37 looking for somebody who knew something about Marcellus, which she did and about
38:42 and inversions. So they hired and that was that was great. So
38:48 went from her career as a flamenco to her career as a geophysicist.
38:57 you can see the interpretation here of logs that she had. This was
39:01 the Marcellus. So this this was fact an unconventional play. And in
39:06 area were these are plotting the seismically features. And what we're looking for
39:15 really mapping those to play content, more importantly, organic content. So
39:27 in this case we've been talking that activity is mapped to clay and in
39:35 in the case of an unconventional, doing the opposite thing out to bend
39:38 brain a little bit. We've always looking for not shale and now we
39:43 looking for shale, but we want show with very specific characteristics. We
39:50 high organic content carriage and content in shale that comes from rock samples and
39:59 . And then in fact of the , we typically want the lowest clay
40:08 . So we want sand or carbonate in with the shale and the reason
40:15 want that, we want our cake to eat it too, we want
40:19 organic content. So it has oil we want it to be brittle so
40:24 can break it hydraulically fractured. So marcellus has been a huge play in
40:37 Appalachians and as a shale. But looking for these two things. Once
40:42 we want high organic content because we oil but and that's usually attached to
40:51 in the shale. So we're looking shale but we want it to be
40:55 of the minimal shale like as possible shales as we said are not rigid
41:02 it's hard, it's hard to hydraulically them. So it's easy to break
41:12 . Glass is basically silicon dioxide and . It's very rigid. If you
41:19 a hammer to glass, you know happens? You don't even have to
41:23 a hammer. Just drop it, breaks. If you drop silly putty
41:27 the floor, what happens? it doesn't break. So we're looking
41:40 these characteristics that have high T. . C. And high silicon.
41:47 that that's just an example that sometimes are looking for shale sometimes not.
41:53 that's why we want to understand how these logs work so that we can
41:56 the same logs and just interpret them . So there's just a bit of
42:03 excursion, there's some other things now showing you kind of the counter examples
42:09 , so for example we might be for potash, not just oil and
42:14 , but maybe we're looking for potash happens to be potassium chloride or potassium
42:24 potassium in it. We want potash make a lot of stuff including
42:43 So we need we need potassium. of our bodies need potassium and plants
42:49 everything need um plants need potassium and podcasters, mind and it's going to
43:00 used for fertilizer. So here's some deposits that have potassium in them.
43:09 then this these are really horrible but that's what we have. So
43:23 we can go through all these logs and this is uh you know,
43:27 are these are kind of hard to , but we can look at the
43:34 logs and once again when we get evaporates, they read very differently in
43:39 gamma ray. So of all this mess, let's just look at the
43:44 ray. So here's our gamma ray you can see that it comes
43:53 down, down, down, we this evaporate layer and then all of
44:03 sudden it goes crazy. So what you think is happening here? We
44:12 go down, we've got zero gamma and then all of a sudden we
44:20 very radioactive sediments, What do you is happening? Are we starting to
44:31 like sale shell layers? Well could , but not in this case.
44:43 else could we be hitting? could we be hitting, Well we
44:51 just talking about the potassium, so could be hitting like potassium so
45:01 So you're you're hitting potassium big It's got huge excursions well over 3
45:10 105 100 intensely radioactive. So logging for a different purpose in this
45:21 we're trying to build a potash So we've drilled it and where's our
45:29 ? There it is. So we this hole, the pot dashes out
45:35 10, 20 m, so 1020 and that's gonna be the top of
45:42 potash mine right there. So just example if we're looking for potash,
45:58 use the gamma ray log for a different purpose and in fact about 10
46:02 ago, some of the companies who looking for potash actually came to
46:05 Of H. And they calibrated their ray tools in our our wells here
46:11 pits. They were, that was of interesting. Where do they get
46:18 word potash from? Is it like stash or something? Yeah, I
46:25 think I think that was, I that might have an it that when
46:31 you actually took this material and heated up, it had potassium, but
46:35 think it also did have ash so , but we'll have to have to
46:42 that. Remember looking that up a back, definitely potassium, but maybe
46:49 residue has this ash like stung. the just out of curiosity, we
47:05 have a quick look at the ferocity and we can see that the neutron
47:13 is very very low. So the neutron is thinking that there's no hydrogen
47:26 . The density log is thinking that a lot of ferocity there and that's
47:39 to be because the densities themselves will pretty low in the salt. So
47:48 it says there's a low density Therefore you must have a lot of
47:52 full of water. But that's not case here. And so the logs
48:01 are very different. They're basically They're completely disagreeing completely. So there's
48:14 in a sense there's this huge crossover which normally we would interpret as
48:20 like huge gas, but in this we're in this salt layer, we're
48:26 evaporates and so salt is, salt just weird in that they're fairly fast
48:36 they're low density. So once I'm showing these because we want to
48:50 what the logs do, what they . And then if you were,
48:53 you were being employed by a mining , a potash mining company and there
48:59 a few around the U. Then these are the kinds of logs
49:03 get accustomed to it, you know what it meant. But this is
49:06 some early exposure. So podcast looks little bit weird. Um we can
49:13 at other things, other materials because talked mainly about sands and carbonates and
49:18 a little bit about salt now, little bit about evaporates, but also
49:24 what do calls look like. And we can walk across this a little
49:31 too. So when you think about , have you ever seen cole have
49:41 ever had a chunk of coal? I think we like had a piece
49:49 one of the geology classes. You've been bad enough to get cold as
49:56 as a christmas present. So that's . Um So call if if you
50:02 pick up a piece of coal, it light or is it heavy?
50:09 light, isn't it? Yeah, really light. So if we're logging
50:14 it, what would you expect the to be? Very low density?
50:20 that's one thing we're thinking of it's not totally obvious, but um
50:30 think we think of the gamma ray could have natural radio activity. Coal
50:34 basically a decomposed plant. And there that much that we've talked about with
50:43 and gas, there's not much that's in that. So coal is kind
50:48 an organic material. And so would expect it to be radioactive?
50:56 no. So we don't expect call be radioactive at all. Now,
51:02 other thing is that coal is really porous and low density. So just
51:11 a gas, do you think it high velocity or low velocity? It
51:19 have fast transit time. No, would it would have no velocity.
51:31 , not totally obvious, but it's it's a pretty light kind of organic
51:36 high porosity material that's not really very consolidated and all that kind of
51:43 So you wouldn't really know. But a guest you think that probably has
51:48 velocity and it does then because it's . Do we what do we expect
52:02 terms of its electrical properties, its or resistive itty. It's an
52:10 Hello? Probably probably low conductivity. resistive it because there's nothing conductive about
52:19 . There's no medal in it. no salt in it necessarily. So
52:28 kind of expecting that pure coal itself probably fairly resistant because we can put
52:35 in anything but the coal itself, would expect to be resistant.
52:39 if you look across here, here's measurements, there are a couple of
52:42 in here. So we drilled through , you can see we're coming down
52:46 down uh this goes from the gamma 0 to 300. So this is
52:53 and 50. So in this upper with gamma ray 250. What do
52:59 think about that? It's um it's pretty high. 150 is pretty
53:13 . And so this is all clay crap and it's in the near
53:17 So only down 300 m 1000 So this is kind of uh fairly
53:25 mucky clay deposition. That is fairly . It's uh you know, it's
53:37 density is there's gramercy three g per . You know, it's it's not
53:44 , it's about 2.4 g per So it's starting to get consolidated.
53:50 wave velocity is somewhere around 3500 m second. So somewhat consolidated. And
53:57 resistance the there's nothing major happening. resistive et all the way down.
54:02 it looks to be all probably briny . So that's it. Then we
54:09 this stuff and you can all of sudden see some real anomalies happening.
54:14 one, the density drops. P velocity drops, shear wave velocity
54:20 So it's not like it's a gas sand because the rigidity of the material
54:28 gone down to not just the compressed . So we hit this it's lower
54:34 it's got some strings in it. lower gamma ray and it's got some
54:39 resistive. It ease. So but it's this density, this density going
54:45 to like one point almost 1.3 or g per CC. That's very,
54:57 light. And even a gas saturated probably wouldn't be that low density.
55:04 , this is a real kicker for . Mhm. Low radio activity,
55:13 resistive. Itty, very low density very low P. And shear wave
55:19 . So those characterized the the Now, one of the reasons we
55:27 about this is number one we might prospecting for coal. There's metallurgical
55:31 there's there's cool that we are interested . But we might be looking for
55:38 fields around this. And the problem this area is with a very changed
55:48 and velocity. If we have a wave coming down, what happens when
55:54 hit this very different impedance? That's you would it bounces off it?
56:06 is a very strong impedance contrast. density and the velocity are very
56:14 So it's like having to slink ease different sizes. So the waves come
56:21 and they hit this and they do penetrate very much. They bounce
56:26 Strong acoustic impedance and elastic impedance That means that most of the energy
56:35 reflected back to the surface, which it's hard to penetrate this to see
56:40 below it with seismic energy. And gets worse as far as seismic goes
56:56 some there's a little bit of energy does get through here. But then
57:02 happens, it happens again, it again. So I slip a little
57:12 of energy through here and then it another big impedance contrast and bounces
57:18 But then it's hitting the underside of so it can't get back so it
57:23 around in here. That's called multi thing. And that's the multiple,
57:32 an intra bed or between bed And now it really screws us
57:48 So multiple just means that I've got bounces inside here and it's trapping my
57:56 and I can't see below it, because it's bouncing around in here when
58:03 process it, it actually looks like layer below that. So not only
58:09 not seeing a real layer, I'm a false layer, so that really
58:17 us. And it's it's it's a . And so we have to,
58:22 we're processing seismic data, we worry lot about this kind of stuff and
58:25 try to got a lot of techniques try to get rid of these multiple
58:30 of these multi path thing, energy this reverberation here because I want to
58:36 down here because there's goodies down There are hydrocarbon goodies. But it's
58:42 for me to see anything through here the seismic role. So that's another
58:47 that we're interested in the coal signature we're gonna simulate this and then see
58:52 we can get rid of its So once again, if we if
59:02 look at another another case, we're down deeper. And uh we've got
59:08 gamma ray logs, sp logs, logs, they're all fairly correlated.
59:15 we're coming down these coal layers are thin and you can see the the
59:21 track here, the resistive itty high resistive itty. And then we
59:28 look at the density or the you can see all these places where
59:38 is an automatic flag for coal. once again, we've got low gamma
59:45 hi rez festivity and low density and putting those three together, that's that's
59:51 call flag. Okay, so once , another, another kind of
60:26 Look at another case. So low , low gamma, low sp,
60:40 resistive. Itty. Cool. so those are some of the some
60:51 the conventional logs and our our view them. But let's let's take a
60:56 10 minute break, Stephanie and then come back. Okay? Hi
61:08 Hello. Okay. Yeah, let's on. We're stepping our way through
61:20 these logs and and then what we see with them. And we talked
61:25 little bit about this before. It perhaps a very simple log is just
61:29 video camera. So you can see device here, a schematic diagram of
61:37 that just actually has a video camera lights and this is a downward looking
61:46 . We can also imagine a different . One that would be a side
61:50 camera. And clearly these aren't gonna too much in an oil well or
62:01 standard gas well. But for for water well that has clear water or
62:09 a well that is evacuated or does contain fluids. This is a good
62:24 . And here are the kind of that one would see again with a
62:28 looking and good if again if it's water or if it's only slightly dark
62:34 , we can see fractures. For going through this particular. Well,
62:42 , now there are some other more , what are called imaging tools.
62:47 are tools that just are trying to a picture of this, the more
62:50 wall and part of this is for purposes for faults for um looking at
63:00 dips of various layers. And so how they work. There are two
63:06 types of tools. One is an tool and in this case we have
63:17 a transducer, ultrasonic transducer that creates little vibration and then it has a
63:27 an area within the tool that with and there's fluid in here so the
63:33 just spins around. So we've got tool a little vibration, The reflector
63:38 spinning around. So it's just making ultrasonic scan of the side of the
63:43 wall. And what it does is we measure. So at every point
63:49 there we measure the time that it to go through the fluid and measure
63:53 from our whole wall. So it's high frequency. You measure the time
63:57 well as you look at the amplitude you just put all those together to
64:01 the amplitudes of the times. And gives a picture of the borehole
64:05 So that's really an echo sounding, an acoustic picture of the wall.
64:11 , the other thing you can do to have electrodes. And so we've
64:15 multi electrodes with a little pad that measures the resistance. Again, it's
64:21 resistive itty tool, the resistance across pad and it looks at all the
64:26 around the formation and makes an electrical picture of the more whole wall.
64:33 two types of tools making the mechanical acoustical and electrical. And when we
64:42 at those pictures, so what we is that you can imagine that the
64:52 is the cylinder. So we made scan of the inside of the
64:58 But then to make a picture of , I just unfold that. So
65:03 again we've got our borehole, that's cylinder. We make a scan on
65:08 inside and then just unfold that. that's the picture that we're looking
65:15 So they the picture over here say marvel television. This is the amplitude
65:24 the little ultrasonic pulse that came back every different area than the tool
65:33 every different area, every different every different area and then we see
65:37 picture and the sine wave. Can reconstruct what the sine wave is
65:54 Yeah. So in this picture we've a sine wave. But what is
65:59 ? Sorry? So you're you're asking what caused it or like what's wouldn't
66:07 just be like a fracture or Yeah, but why does it look
66:10 a sine wave? Because I mean it's I mean it's a flattened
66:32 I'm not I'm not sure why it be assigned specifically. I'm gonna do
66:41 right now. Um Okay so suppose got a borehole like this. I
66:50 take the piece of paper. You do this too. So here's here's
66:56 borehole and then suppose there was a or a layer that went right through
67:06 . So let me see if I do that. So effectively there's a
67:13 that goes right through this. So is just a layer. Okay you
67:30 see when when I put that Okay let's see it. So that's
67:42 just a basic construction when a cylinder cut by a plane and you unwrap
67:54 the cylinder, the plane cut is sinus line. So you can imagine
68:05 we take this this left picture which just a panel but it's really the
68:12 inside of the cylinder. Now if wrap this right part back to the
68:18 part that I think you could probably that that becomes a lips and the
68:24 is just a cut through a So this is really if we wrap
68:32 again, it's really just on the and on the inside of a borehole
68:35 plane or cut through the bore hole an ellipse on the borehole. Then
68:40 we unwrap it it looks like a like. So this sign is the
68:50 image of a dipping layer on the of the Warhol. Now that's the
68:56 picture, that's just the amplitude, travel time tells us that the but
69:07 has a little bit of of a into the barbell, it's it's faster
69:17 that might mean that this fault has in it and there's a bit of
69:22 on the inside of that fault. it could be that this is just
69:34 a stringer. A dipping stringer of kind. Probably not, but it
69:38 be a dipping stringer that's a little more resistant than the rest of the
69:43 hole. Now um The ran they ran the resistive itty log and the
70:01 . The log only has four pads it and it's rotating a little
70:04 So it's got four pads that are measurement. So it doesn't measure everywhere
70:08 the borehole wall, but it gets of it to give us an indication
70:13 that this fault or fracture or uh layer has a different resistive Itty.
70:21 fact it's more conductive than the other . So it just gives us an
70:26 that there's some kind of plain or and which they identify as a
70:31 Um And those are the those are types of pictures. So this is
70:39 an image of the inside of the to tell us something about what's happening
70:44 the layering or the faulting or These image logs are often used for
70:50 because our other lives don't really see fractures as much. So if we're
70:56 in that then we have to run other lines. Now we can interpret
71:07 a bit more quantitatively and you can that probably the shallowest excursion on this
71:15 is in the west, the deepest is in the east. So I've
71:22 my board hole like this, then can see that dipping from west to
71:31 is the dip of the fracture. so computer programs are gonna try to
71:39 different sinus sides to that and from amplitude of the sine inside and then
71:45 direction, figure out the dip and azimuth of the fracture. And so
71:52 will be done automatically too. So we go. We've got the,
72:00 the resistive itty scanner here and then ultrasonic borehole image. They're here and
72:06 gonna fit the curves and then make picture of that. So once again
72:15 our unwrapped cylinder. We can see nice curves. If we wrap that
72:19 , that'd be an ellipse idle Then I can see here um the
72:28 is sort of in the south direction the amplitude of this tells us how
72:35 the dip is. And then that's on what's called the tadpole plot.
72:47 that's that's how we uh interpret these . So what exactly does this
72:56 Well, uh we've got a scale it's in degrees. So this is
73:02 the amount of depth going from zero to 90 degrees. So once
73:16 if we had a low a low dip, it would have a very
73:23 peak to trough. Excursion. If got a very high angle death,
73:29 gonna have a high when I unwrap , it's gonna have a high sign
73:32 a large sign inside then from the of the maximum to the minimum.
73:39 gives me my dip surface and that me the direction. So this we
73:48 these guys the way they plot them just like a compass. So this
73:54 pointing in a south southwest direction. that this dip is in the south
74:04 direction. And here is the angle the angle goes from 0 to
74:20 And we have to look at the what their definition is. So this
74:26 typically going to be from from the . So um that's that's how we
74:53 interpret fractures on an image log. you can see as kind of processing
75:02 . We would, if we are a computer program that would do
75:06 we would just try different scientists voids cross correlate them with this image and
75:12 see which amplitude and shift correspond to best coherence. And then have the
75:19 extract that number for the orientation and amount of depth, I'm not gonna
75:33 so with that first one, would be like that top green pin?
75:37 that would be like 55 degrees to northeast, this guy right here.
75:46 . Uh No in this one it's to be let's see 10 2030 40
75:57 almost 60 degrees to the southwest. okay. Oh so I was okay
76:10 I was thinking the pen was going the direction of like a northeast,
76:15 , compass. Yeah and it's it's gonna depend typically the leg points in
76:25 direction of death. That's true. , so let's see, let's so
76:42 on the standard, this is going be south in the middle. So
76:47 can see that here's here's here's one the definitions back here. So we
76:54 north east, south west across the we're starting out at north here.
77:03 we know that north is the highest and east south west, north north
77:13 the highest point and south is the point. So this is more or
77:17 dipping to the south so we can that that's strictly because the way they
77:23 , this is north here, east in the middle. And so that
77:30 is dipping down to the south and can see the plot here. The
77:36 tail of the tadpole is dipping more less. It's slightly we said this
77:42 north east, south west north. this is slightly off center, it's
77:50 to the west. So you can they're extracted Tadpole is slightly to the
77:57 . Okay, that makes sense. let's look down here, they've they've
78:06 these blue traces. So if they you can see a little bit
78:11 So it's not, most of most the stuff up here is dipping slightly
78:17 the south. But if you look this stuff they've extracted some other traces
78:21 can kind of see but here here's traces they've extracted. So in this
78:25 north is deeper. South is So if we look at the
78:34 which way do you expect the tail point? And this this is just
78:41 looking down on a compass. so then it would be, so
79:00 here's north, here's south, south higher. North is lower. So
79:09 going to be dipping to the north the north to the north. You
79:14 the little blue tadpoles here and these broader excursions. So that means that
79:27 almost they're sub vertical or they're going to 90 degrees. So this little
79:34 has a big excursion. The south high so it's dipping to the north
79:43 it's close to vertical. And so can see the the plot here.
79:52 can see that little guy there. . So part one is, here's
80:01 the image log itself and you look this. First of all we'd
80:09 hey there are a lot of fractures or betting or something. There might
80:19 some cross beds because these disagree. got some of it that's dipping
80:24 some of it's dipping north. So might be some general strategic graffiti is
80:32 . But then inside that you've got beds that are dipping the other way
80:38 that grossly dipping against. So this be cross bedded or something or it
80:44 be multiple faulted and no, they interpreted this differently so they've said that
80:54 green that's bedding and it kind of like very consistent bedding. That doesn't
81:01 like a fault because you wouldn't expect false maybe so perfectly aligned. And
81:09 is thicker too and it's got a thickness. So they've interpreted that the
81:14 is in green but there's faulting. we've got the bedding dipping but now
81:21 faulted and maybe their conjugate faults or like that. So the faulting is
81:26 the opposite direction. That's their interpretation . That makes some sense. So
81:42 . So once again with these we're we're scanning on the inside of the
81:46 . We can do that two ways can do with an ultrasonic pulse and
81:49 echo. Like a megahertz little ultrasonic . We can measure the amplitude coming
81:54 or the transit time and we can a caliper against the border wall and
82:01 micro little electrodes on it that are the resistive itty right on the border
82:06 from all different pads. So we make two different kind of pictures from
82:12 . Typically we're gonna be looking at or fracturing and then the plains of
82:23 or fracturing show up on a two . Page as plainer cuts through a
82:32 that are sinus. I'd like looking can wrap this around in your mind
82:36 think that it's just an ellipse. then we extract the dip of that
82:41 well as the orientation. And that's we want to get out of
82:43 So that's what the log is. gonna tell us where the fracturing of
82:47 betting is and how intense it These aren't as common because they're expensive
82:54 . And so you have to be for something quite particular like fractures.
83:04 you can see that they can become complicated. Here's the here's the
83:10 we scanned our log. Here's the from the log. When we unwrap
83:16 paper on the cylinder. This case plotted it a different way they've got
83:22 on the edges and north. We to know which way they're plotting.
83:26 then you're going to correlate and extract features you can from this and then
83:34 that up. And so in this they show that most if we look
83:41 each one of these tadpoles, they're horizontal, so only 10 or 15
83:50 . And you can see that from , they're pretty flat. So most
83:53 these features are fairly flat. And when we look down on this and
83:59 like a compass, where do they ? Most features are dipping. We'll
84:05 right around here. What's the dip features around 3700 m. Um around
84:14 . They're dipping to the south west . No north south east. Yeah
84:29 we're just looking at this as a northeast southwest. The dip is more
84:35 the south east. Now let's go and see if that makes sense
84:46 So Supposing that we go back this might not be the same
84:57 That's why I got confused cause I looking over there and I said
84:59 wait. Yeah. Well the you know the the deepest part on
85:11 of this stuff is so this this this is not directly related to
85:19 These are schematics from different areas. , but reading this guy whenever it's
85:24 from this is saying that I've got like 15 or 20 degree dip to
85:29 southeast here. But you can see changes as we go down deeper in
85:34 particular case. All of a sudden getting other dips that are to the
85:41 that looks more like here. So we could, you know,
85:50 you're gonna get to look at this detail, then you can start to
85:54 something if you build a geologic model your mind. And what we've been
85:59 at with all the other logs is kind of a one dimensional picture that's
86:05 . What this log is trying to is to give us some some really
86:10 dimensional information because remember everything we did was just one d we're getting the
86:17 right at that. Well and a away from it. And we kind
86:21 imagine that all the layers are Which is true for a lot.
86:26 in some cases of course we've got . So even though we're logging just
86:33 one line, if I could, really like to know a little bit
86:38 what's going on geologically away from So the, these tadpole plots can
86:50 us an indication of the dip in rock too. So that's why they're
86:58 . So we're getting not just this is all sand, which are
87:02 logs are gonna give us, that's the sand. It's got this
87:05 , it's got this permeability, it's this saturation. Great. So I
87:09 that right here. But can I anything about what's happening or the trends
87:13 anything else? And so that's where , these image logs can help us
87:17 . And then can we say something a fractured? Are there naturally fractured
87:22 ? And so those are just things can help, I like image logs
87:26 great. They're just not as common they're expensive. So the other aspect
87:35 we talked about this a bit but say from the acoustic log we
87:40 a travel time and from the center here, we can actually see if
87:46 travel time is longer, then that kind of another caliper log and that
87:54 help us and if we can see it's longer and we can look at
87:59 reflectivity, just the echo from the , then maybe we can say it's
88:04 and it's also fractured and does the go this way or this way and
88:08 gonna tell us whether it's a natural or maybe a drilling induced fracture or
88:14 it is. So we can get even more from this. So we've
88:21 our our unraveled log, I can at the the fracture but then I
88:29 also look at whether I've got a radius or a large radius and then
88:37 at the patterns of the breakouts to what might be drilling induced a drilling
88:44 fracture versus a natural fraction. So can push the interpretation of these lives
88:51 little bit to tell us about stress Iraq and what we're really doing is
89:07 trying to uh but all these logs so we can figure out as much
89:12 possible. So there are ideas that want to do is make as many
89:19 as possible. This happens to be a medical aspect and these have to
89:28 my knees. But you can see the x ray image of the knees
89:37 then you can see an M. . I. Image of the
89:51 And you can see that this knee irritating me a little bit.
89:58 But the point here is that in we use all these different images.
90:02 using M. R. I. which are, you know, the
90:08 magnetically induced wobbles of radio waves in knee and we can use x
90:15 the x ray absorption. And that's X ray picture here is really the
90:20 of x rays and bones absorb more flesh. And so we get this
90:26 picture with M. R. This is really a picture of
90:33 And so we get that. And of course if you're an interpreter,
90:37 you're a bone interpreter you're going to looking at all these various details comparing
90:42 to this, seeing what the problem here or what the anomaly is.
90:45 that's just really what we do We're looking for all the different
90:51 all the anomalies and trying to typically something that's different now that brings us
90:58 these NMR logs, the nuclear magnetic logs which are a little bit more
91:08 and are used but again sort of specialist blog. But the generally there's
91:22 lot of processing that goes on. the the general idea is that we
91:29 first of all that we've got very magnets. Then we've got a very
91:36 magnetic field. Then we put a in that very strong magnetic field and
91:44 moments of the hydrogen atom uh can made to process. So this is
91:53 it works. You put a radio policy in and that kind of pushes
92:00 magnetic moment of the the proton and processes and as it processes it radiates
92:10 radio frequency wave and we measure So this is more or less how
92:19 . R. E. S. . Have you had one? Have
92:21 had an MRI scan? Um I think I've had an M.
92:29 I. I think I had something with my liver one time but I
92:34 know if he was an M. . I. Yeah you might have
92:37 you probably had an ultrasonic scan because lots of ultrasounds. Probably. Yeah
92:46 they're used a lot just because they're vibrations. And so they they are
92:54 risky at all for you or for child or. So they're they're they're
93:02 a lot with pregnancy just because they're they're not radiating, they're not ionizing
93:08 . So it doesn't harm the child you. Um These these guys are
93:14 bit more intense because they in the they put you in a large
93:20 you're bad and you go through that chamber is a superconducting magnet. And
93:26 again with this M. R. . It works by putting material such
93:31 me or you in this area, a very strong magnetic field put around
93:40 . Then there's a a little radio pulse that causes all the water nuclei
93:47 hydrogen nuclei to process. And then go around and you measure the procession
93:52 all those and it basically is a scan of water concentration. So that's
94:05 way it works. And then you this and then you look at the
94:11 or the processing of the nuclei, spinning around and they're processing, you
94:17 at the frequency and how they And that gives an idea of water
94:22 , hydrogen concentration and then basically water . So that's uh that's done for
94:31 rock. And this uh you can a very, very high intensity magnetic
94:40 , a radio frequency device, it the rock and then you look at
94:44 processions and the periods. And then that extract how much hydrogen is in
94:52 material. So this is a game kind of a nuclear log. But
95:01 good thing is that it's not injecting into the formation. So you don't
95:06 to handle cesium or admiration beryllium or don't have to handle these radioactive
95:12 If you're if you're logging engineer and in the truck, you're gonna be
95:16 a radio activity badge or something and gonna have to be very careful about
95:20 the sources and so we don't really to do that. So this other
95:25 determined ferocity is good. So one log, it's an N.
95:33 R. A magnetic resonance imaging log also gives us uh ferocity.
95:44 so that's that's most of our logs are, that are used their little
95:50 that are being developed all the Any any kind of physics. Somebody
95:54 try to put it in a logging and see if we can make some
95:57 out of it, um what NMR nuclear magnetic resonance logging as far as
96:07 , usually trying to find the details ferocity and uh and water saturation.
96:16 , once again, you can see number of wells that are drilled something
96:21 half a million water wells are drilled year in the US. So you
96:29 want to be logging those to figure everything about the mythology. And so
96:35 example, this study in Denver was to find out much more about the
96:39 because we've got cities say Denver out , you're looking for, how
96:44 how does water recharge and get to ? And so they were interested in
96:48 at all these water wells and getting chemistry and the ferocity ease and the
96:55 and they were using NMR logging for . So we've talked mainly about the
97:04 world, which is great. But just to think about water well
97:08 So our water wells are typically more , like around 202 103 100,000 ft
97:18 you're unlucky a little bit deeper. the the problem about going deeper for
97:28 is what I'm trying to drill a . Well I haven't found it.
97:32 I keep on going deeper. What's problem with drilling deeper? Um Well
97:44 one, you gotta get it what did we say about deeper water
97:54 ? Oh it gets salty. yeah, so unfortunately you can't drill
98:03 deep or the water is gonna get , it's gonna be briny. So
98:11 most water wells are going to be or not at all, you're
98:17 you're just out of like, but around here that's why we drilled the
98:23 in Lamarque down to 400 ft because main aquifer in those parts is at
98:30 450 ft. So we just went the very top of the aquifer.
98:34 were not trying to find water, were just trying to drill an educational
98:38 of wells so we don't want it don't want it to flow. So
98:59 again in logging a water well, uh like first of all we we've
99:07 a well and in this case you see that it's really watched it a
99:17 now we didn't, we didn't really this level of, of washing and
99:23 in the oil wells. Why do think that might be what's different
99:36 Well it's different. I mean the looks, it does and why why
99:43 that be um will those be, , those wouldn't be a washout.
99:58 Is it just like a super permeable ? Yeah, more or less we're
100:03 the near surface, it's unconsolidated. just, I don't know what this
100:10 , this is from pennsylvania someplace but the near surface it's probably just un
100:16 , You're drilling through soil and slump materials and it's just washing out so
100:26 you're going to have to do in wells is you're gonna have to drill
100:30 and then get casing in it because these wells slump and cave in as
100:39 well will but you can imagine if in a nice um limestone from west
100:47 in the near surface, you're gonna it and it's gonna stay as a
100:51 hole for a million years. But I'm in soil around here and I
100:58 drill this hole and I don't do , it's gonna just fill itself in
101:01 short order. So you can see what then we look at the gamma
101:07 and what do you think with the ring? Um I mean it's jumping
101:18 in like small sections, but what the yellow telling us isolated. And
101:28 let's see, so like right there like one and two. It's kind
101:36 a wait, I'm looking at the . The gamma. It's a little
101:44 right there are so high gamma. then you go to low gamma and
101:49 a little high again. But you a really high gamma down there between
101:56 and five. Yeah, but this water. So why is it?
102:15 , they're they're interested this is getting a slightly more advanced part. They're
102:21 measuring, they would have a little down there. So they're measuring water
102:26 , which is another log we could we could have a tool that just
102:30 have a spinner on it, a , a fan and as water comes
102:36 or goes out of the hole, can measure movement of water, which
102:39 what they're plotting here, that there's lot of different stuff happening. But
102:46 can see that water is basically coming the bar of all here, the
102:50 areas and then it's exiting from the , so that the circulation patterns from
102:59 pressure water to low pressure water in intervals in the earth. That's why
103:06 you're drilling these wells, you do to isolate, you have to case
103:09 multiple because the water from one level flow into the water from another
103:14 might flow into the water from another and everything else. So the water
103:19 tends to mix in the near surface all the different aquifers. And so
103:23 plotting some of that here for our . You can see that there's some
103:30 that are sandy, but all this is pretty clay, like it's all
103:38 high gamma. Although, look at , this isn't counts per second.
103:42 have not calibrated their tool in api because they're not oil industry guys,
103:53 that should really be calibrated api but we're gonna take the counts per
103:59 or pretty close. So down this is a sandy layer and you
104:04 see that it's also very resistive. we're probably thinking that that is fresh
104:13 nice and fresh one. So if we were looking to produce areas,
104:37 are probably doing that. So in words, my interpretation of their isolation
104:42 is they're probably plugging this, these areas, they're not allowing anything to
104:48 there. So we're going to produce here, this is probably nice sand
104:54 from there. Maybe produce a little from here. We uh might
105:03 water might not want water to go there and this doesn't look like it's
105:09 necessarily do that anyway. So, this is just really an example of
105:14 we use the same kind of but for a different purpose.
105:18 we're looking for resistant areas, probably of fresh water. We're looking for
105:24 because they're going to have higher ferocity likely be our, our aquifers and
105:32 we can deploy different tools that are production related tools. These will have
105:36 so that we can actually see what's movement of the water, not just
105:42 possible kind of mixing of salinity is actually gonna look for water flow and
105:54 a kind of standard number. So is gallons per minute. So
106:00 this isn't, these aren't really big wells or anything, this is a
106:05 of gallons per minute. If we're a subdivision, you know, I
106:12 want to see a couple of gallons second or something like that.
106:19 so that that's kind of the static and then start to move a little
106:26 into dynamic logs. And then when talking about flow itself, this is
106:33 a little bit more in the the production area and the reservoir engineering
106:38 . We have looked at a little of a permeability, but then in
106:45 background, what do we, why we care about that? And it
106:49 to do with flow? And we're looking at water but we also wanted
106:53 outflow of oil and so you can that the flow of a fluid depends
106:59 the pressure difference between the entrance and exit. So the pressure difference across
107:07 . And as you can imagine if easy or permeable that enhances the
107:12 if we've got a bigger area that the flow. If we've got a
107:17 viscosity or a small number here that the flow and the shorter the
107:23 That means Ella's short, that enhances flow. So this is Darcy's live
107:30 it's pretty, it's pretty intuitive. blow on a pipe mark comes out
107:37 other end, if you take the out of the pipe, you can
107:41 more through it. If the pipes and wider, it will produce
107:45 And if the fluid itself is lower , it comes out of faster.
107:53 that's really Darcy's law, we are to talk too much about that except
107:59 we would give the engineers and the simulator guys a full picture of
108:11 the area of interest, the the porosity, the permeability of
108:18 We would maybe tell them a little about the viscosity of the fluid and
108:22 they would put it in the simulator different pressures and see what flow you
108:27 get out of it. And so exactly where most of this stuff eventually
108:32 . We're going to build a three . Model of all these rock properties
108:36 the fluids and then hand that off the reservoir. Engineers with simulators and
108:41 are going to simulate how the well flow. Then they're going to flow
108:50 well for a few weeks and months see how that matches the simulation.
108:58 then they're gonna tweak the parameters of of the volume and of the the
109:06 and the pressures and then try to the production. So that's called history
109:14 . So they're going to try to the production and then they're gonna say
109:20 think we can produce this field for years at these rates. So this
109:23 going to be your ultimate recoverable And that's what you're going to book
109:32 your reserve and that's the number that's to go directly to the stock
109:41 And then like we looked at that's your reserve number and you're gonna
109:48 that barrels by 100,000 bucks and that's your resource, that's what you're worth
110:02 . Okay, so that's a game where we're where we're going. So
110:12 have a quick look at a case uses some of these wells and puts
110:22 whole idea into perspective. So here's here's a little case that a friend
110:32 mine was working as a consultant for company. This company ran a three
110:40 seismic over a few areas and he and the company decided not to pursue
110:53 it. So he recommended that they it, the company decided not
110:59 And so they walked away from it so he always had it in his
111:05 that he'd like to go back and drill it because they didn't want
111:09 So when a certain amount of time , he bought the rights to the
111:17 and also started to assemble the land here and get the rights, Talk
111:23 all the farmers and everything. This in California, talk to everybody because
111:27 wanted to drill this and then the it works, he went around and
111:33 put this play together this prospect together seismic interpretation and the targets and the
111:41 costs. And he went around to his friends and business associates and
111:46 would you guys like to buy into plate? So a number of people
111:56 included, we said, yeah, , we'll give you, we'll buy
112:01 of that, we'll give you some and you can put this all together
112:05 raise money and drill as well. that's really how the small guys
112:15 So we actually went out to the and we're on site and he drove
112:19 so so you can see that on seismic here, we've talked about this
112:23 a gas prone area. So that bright spots, what's called a bright
112:29 . That's a high amplitude reflection. bright spots, a high amplitude
112:39 And on the seismic data we can a number of these bright spots.
112:44 the interpretation is that their gas saturated causing a big decrease in density.
112:50 we've looked at the decrease in density in velocity gives a big contrast and
112:56 a big reflection off the top of . So these high amplitude reflections called
113:01 spots. We interpret those to be saturated sediments. And that's what he
113:08 on the plate. So then we the well said we're going to
113:13 In fact, we're so smart. gonna deviate, we're gonna place the
113:17 that we hit all of these targets one well and that's, we
113:32 So went out to California and drove well. It was all very exciting
113:41 . We can look at the, volume of seismic and just extract only
113:46 high aptitudes and now we can see . There's the well trajectory boom and
113:58 here's our classic so we can go and start looking at the the well
114:08 . So now we've drilled the well here are classic logs. Just a
114:15 snippet of them. So what do think? Well, caliber looks
114:35 We have low gamma. Yeah, have a lowest gamma. What's,
114:45 um, mm B um Actually, not sure. Um Okay, so
115:00 off those, they look good. , so we can see once
115:05 when we look through here, here's gamma ray. There's a there's a
115:12 sandy nous there, which is And you can see that the interpretation
115:17 yes, you've got a little bit sandy Nous there. So that's
115:23 And then we go to our resistive lives. Mhm. That one area
115:35 higher resistant li that's the deep. that's that's good. Then we've got
115:47 density porosity and our neutron ferocity. what do we see? Nice
115:56 nice crossover P. E. Tells we've got some Sandy Nous.
116:13 So uh that's a little sand. one. Great. The problem is
116:28 these are all something like one or ft. So it's a sand,
116:34 gas saturated but it's pretty thin. . So that's that was target number
116:45 . Target number two. Let's get one. So once again, the
116:53 . Okay, gamma ray has got little bit in there, come over
117:00 it. He's got a nice kick us. Frosty lives Cross over
117:06 Good. Guess what target to another sand. So now we're starting to
117:12 that we're really smart. Target three deal little little cleaning areas of the
117:25 ray. Small sands, good kicks the resistive. The logs and nice
117:35 on the ferocity logs good target for quite as exciting, but a little
117:49 little bit of gas sand in So uh bottom line in this was
118:06 interpretation of the seismic was bang on drilling was excellent. We hit four
118:13 , but two things happened. The is a bit, the sands are
118:18 bit too thin to be economic. . They weren't pressurized that high and
118:29 were mixed with nitrogen. So we a pipeline that PG and E pipeline
118:36 within a kilometer. So, and was prepared to accept our gas and
118:44 had this radically great geophysical success about four targets beautifully. But the targets
118:53 full of nitrogen as well as So, so the gas in it
119:02 compromised, co mingled or mixed with . Now, as you know,
119:08 nitrogen in the air. So does want nitrogen from your well, mhm
119:15 . And if they've got their nice gas pipeline and can you put nitrogen
119:20 their pipeline? No, you have put beautiful natural gas in their
119:28 So we could have done that. was natural gas there. But you
119:34 to put a refrigeration unit on So you have to separate the methane
119:40 the nitrogen sort of like what a of your clients that the business would
119:45 something like that and you have to the quality of your natural gas
119:53 which is going to be for some . Like you would make. So
119:57 we have to guarantee that it's 99% or natural gas. Well that means
120:04 we looked at it means you have buy a million dollar refrigerator, take
120:08 natural gas, cool it the nitrogen become liquefied and you can take the
120:18 but it's too expensive to do. gas again is pretty cheap here and
120:25 you cannot afford to do all that with natural gas. And so I
120:32 very happy to get the well logs not retire to a beautiful estate in
120:42 , which was very hurtful. I thought target four was gonna be
120:48 lot more exciting based off of the the slide number 44 because it just
120:56 so big and you know, it uh it probably is that big.
121:15 when you actually look at the rock , you'll see that introducing just a
121:19 bit of gas in the brine. you probably saw with Castano's courses,
121:24 a little bit of gas, like or 34% of gas changes the p
121:30 velocity a lot. Mhm. So this case you've got sand, we've
121:44 a little bit of gas here, it's just a little bit mhm.
121:53 it's probably fairly extensive and so that Jif was probably right, but it
121:59 wasn't concentrated enough. Yeah, so decision was I did not want to
122:12 this go actually because the guests we this a few years ago but the
122:18 was cheap at the time. But feeling was hold on to it.
122:21 actually did hold on to it for couple of years that leases, but
122:24 have to pay for the leases every . And so not everybody wants to
122:29 in and continue paying for this stuff it's not making any money. So
122:34 a couple of years of paying for and gas prices didn't improve. The
122:39 was bail. Let's get out of . It was kind of too bad
122:46 there was gas there. And if prices had doubled, it would be
122:51 it to build a refrigeration unit. in the end it probably was good
122:56 gas still is not expensive now. that's that. Anyway, that's a
123:03 case. And it was close. was a geophysical success, remarkable success
123:08 44 targets and they were gassy and were sandy. It just the wrong
123:16 and not enough. Oops. So room for improvement in all this
123:23 Great. Okay, well let's let's 10 and then we'll come back for
123:27 final session. Okay. Okay, . Well, great. Oh
123:47 Just sent me this that I was about India and I hadn't seen
123:57 He just said it. Uh, here we go. I've met,
124:03 mentioned this. So here's the the and here's where we're talking about these
124:32 offshore India, all this stuff and have the first couple of tapes I
124:37 , hadn't seen this before. It came out. It's always nice to
124:41 what you're doing is announced before, know what's going on? Well,
124:53 , that's good news. Okay. just, uh, I just wanted
124:57 see that um, back with us . Um, here's some work for
125:05 from Andrea, paris, you might Andrea, wasn't she our ta for
125:14 ? I believe she was. sorry, wasn't it Her and Zoe
125:22 . Yeah. Okay. So and so, and they're, Andrea's
125:30 wrapping up her PhD right now and need to talk very soon because hopefully
125:40 been working, she's been working full and it's gonna be working this this
125:46 . So, but her stuff is the bacon. So I want to
125:50 this as another example of an unconventional . So in this case we're pretty
125:59 in the shells and the bacon shale something you should be familiar with.
126:05 is one of the biggest in North is producing something like pushing a million
126:14 of oil a day, huge production largely from this block and shale unconventional
126:21 . So this is another one that's important to have a little bit of
126:27 with. And you said this was North Dakota. Okay. So the
126:34 B A K K. E. the bacon is a huge producer.
126:39 changed the economy of North Dakota and stretches in the neighboring states in the
126:48 , I think in the South If you look at the whole Williston
126:53 . So the bacon, the bacon contains a lot of that. But
126:58 , it's got a very distinctive It's, it's like an oreo
127:04 So just think oreo cookie, I have any trouble. Thank you with
127:09 cookies. I like them a Or even fudge cookies. Dare fudge
127:15 are also good. So we've got crusty stuff on top and then we
127:19 a filling and then crusty bottom. a sense, they're a little bit
127:23 inverse of a, of an oreo . So you can see the,
127:31 we just walk across this again. now let's look at the far left
127:40 and you can see the um the ray log again. Now you can
127:52 the way that Andrea has partitioned She's picked the upper and you can
127:59 the big excursion here, so that's Shelly, that's the upper block in
128:09 and then we go through a very area and then we hit the lower
128:15 . So these are really the two layers right there. Then we
128:24 we could decompose these into various minerals , Dolomites, shale materials. And
128:35 again we can look at the density as well as the, the ferocity
128:43 . And we said, we said before that, the porosity of shale
128:46 actually can be pretty high. It's permissible, but it is porous,
128:54 , there's carriages porosity, there's carriage in it there's organic content. And
129:00 here we can see again that uh the measurement for porosity is fairly high
129:06 these shales. So lots of potential organic content. No, they're using
129:17 resistive Itty logs and a few other and some relationships and calibrating those with
129:23 samples. You can come out with mapping from resistive Itty too total organic
129:32 . So this is the carriage and the organic composition that's inside the
129:40 So you can see in our two layers there's very very nice organic
129:49 So we like that. Then we look at the velocities. So these
130:06 fairly low velocity. You can see p wave, low shear wave
130:12 The acoustic impedance is are fairly And incidentally this intervening area has quite
130:19 velocities, no organic content, virtually porosity. Then we come across to
130:37 water and you can see that the is evaluated as actually having fairly low
130:45 in it. So the hydrogen that's detected is largely oil. And then
130:55 have we have some water in these units. Now we haven't talked about
131:05 but there's there's something called a brittleness . The brittleness is how breakable the
131:13 is. And that really comes from measurement of the rigidity and the compressibility
131:23 the the carbonate or the silica So we can actually make a measurement
131:30 how breakable the rock is. And can see that in the shale,
131:36 rigidity, The brittleness index is very . In other words it's just not
131:42 brittle. These shells are not So the upper shell and this lower
131:48 that have all the goodies in all the organic material are not
131:54 We talked about that. However the between these is quite brittle and it
132:07 have it can have basically glass in or basically sand and some carbonate.
132:18 the sands and the carbonates are quite and can be broken. So the
132:24 character of this is shale a bit hard sand, that shell. So
132:50 do we get at this? What you do now? We're going to
132:56 a horizontal well so we understand the of it right now. Here's the
133:01 , the upper level of goodies, lower level goodies. And I gotta
133:06 this and here's kind of a rigid between if you had to put a
133:14 well in here then hydraulically fracture, would you do? Um Like where
133:29 I go in at it or? ? Well I mean the shell there's
133:44 mushy if we if we land a and we put a well through here
133:53 we try to break it. It's gonna deform. So this is like
134:01 . And so what I'm gonna do I'm gonna drill in the middle of
134:04 glass and then break it. Okay then so I'm gonna land in this
134:14 drill horizontally and then break it and hydraulic fractures in principle are gonna break
134:20 through both of these levels. So that's pretty much what's done okay.
134:30 not like this is plastic scene or , it's still rock and it's still
134:33 and it's still it's still down at ft. So it's it's got some
134:39 but not that much. So we'll the well in this middle unit drill
134:47 pressurize it up, break it hydraulically and try to have the fractures go
134:54 the upper and the lower unit. so we're tapping the resource in both
134:59 those. Mhm. So that's the in the unconventional, this is really
135:05 way that it's done. This just to be a very nice signature where
135:09 got to malleable high T. C. Units that are on either
135:14 of a very breakable. You're And uh that's really how it's how
135:27 produced. I'm just gonna quickly see the what's the production in the bacon
135:37 now North Dakota monthly oil production well 10 years ago was half a million
136:07 a day. But I'm sure it's you just have to have a
136:21 It's it's it's almost certainly about a . Um If we look at North
136:31 oil production. Well good thing for time. Okay. And this is
136:56 than the stuff coming out of west , right? Um You know I'm
137:03 a good point. I'm actually not . I would guess that it's
137:08 But uh that's a good question. not I'm not sure about that.
137:15 that's another that's another good question. that will happen fast api gravity of
137:25 and oil. Well, um good . Here's here's from the north
137:42 It says that it's actually fairly light up to about 40 degrees A.
137:45 . I. In fact it's 42 . In fact it's lighter than west
137:57 . Interesting. Yeah, it's actually beautiful and it's 0.1% sulfur. So
138:08 is arguably better than west texas. that's um that's very nice at least
138:20 that one little number. I just very beautiful crude oil, very
138:26 virtually drinkable and low sulfur. So very nice. So once again,
138:38 what we're trying to do um remotely trying to get density and acoustic impedance
138:45 is density times velocity. If we these two numbers from our seismic that
138:52 cross plot what the number is and that's related to all of our log
138:57 um course studies. So if we an Ai at 25,000 and the density
139:05 say 2.3. Then we know that in a pretty nice area. So
139:10 the exploration technique we'd like to do the seismic processing inversions. Get
139:19 two numbers out. Do all of rock physics from what we know with
139:24 and then convert Ai and row into T. O. C. Number
139:28 then put a map out with O. C. And then go
139:38 . Okay. And uh I was a conference in Galveston's and was just
139:45 , I was looking out my window the resort and just thinking what what
139:49 bacon wells are really like. And the basic idea. This was
139:57 here was an image. This was of our inversions. And so this
139:59 something like 4000 ft and we proposed well like this in the bacon.
140:08 this was our our best area that thought combined the characteristics of break
140:16 brittleness as well as T. C. So here is the well
140:20 we propose through this anomaly. This strictly the seismic inversion. And then
140:24 at my window, there's the sand the beach and this was about a
140:30 . And so effectively this is really you're proposing if you're going to drill
140:34 horizontal well with a 5000 ft reach sand, this is more or less
140:40 you're doing. So it kind of the help of it to see this
140:46 of scale. Okay, so that is a brief excursion through some
141:04 We talked about that. We talked a little bit about core and core
141:08 and then we talked a bunch about and then we ran through quite a
141:15 cases of logs and you've got some with picking these likes. And then
141:22 had one little assignment for you to a couple other levels of that,
141:28 one log sweep. So now I've kind of dropping these ideas in about
141:36 else does log analysis go. So now we've been thinking more or less
141:40 petro physicists and log analysts and doing they do to help in the exploration
141:47 . But now we want to think like geophysicists, exploration ists who are
141:55 to explore or develop or monitor once as you've seen in other other courses
142:04 want to go to from the geology the seismic record and then back
142:11 So we imagine we've got some We've drilled a well this is not
142:15 good story, that's a dry Uh but we've got our well log
142:21 from the well log we take the in the impedance impedance that gives us
142:27 reflectivity, we vibrate the surface and we get bounces off this reflectivity.
142:37 modeling is to take a bunch of parameters and construct the seismic response.
142:49 that's kind of the forward problem. inverse problem with the processing problem is
142:54 got and I've shot a survey. got my reflectivity. How do I
142:58 back and make a real geologic So we're always going back and
143:05 And just for you to remember we that the acoustic competing service or
143:15 Here is the density times the seismic . That's A. I. Or
143:31 the reflectivity. If I have a coming down and I hit this uh
143:36 interface, then there's a certain amount that energy that comes back. And
143:45 your seismology courses you went through energy and reflectivity. But the very simplest
143:52 of acoustic reflectivity is lower impedance minus impedance over the sum gives us a
144:03 impedance change and that's it. The impedance changes the reflection or the reflectivity
144:16 the amount of energy that's returned. the amount of energy that comes back
144:24 amplitude of the echo is the reflection . And that's just the change in
144:30 acoustic properties over the sum. So difference over the sun, that's our
144:42 . So we remember to that from logs we construct a reflectivity log.
144:56 we imagine that now we have to that. And so we imagine that
144:59 got a vibration from the surface coming and it hits that reflectivity and it
145:05 back. So we effectively replace that coefficient with a band limited version or
145:14 actual shape itself. And then we have our log that was originally in
145:22 . But if we know the we can change that depth into a
145:30 and then our shake is in And for every reflection coefficient we just
145:36 the shake and then add it all to get what would be the response
145:44 this column. So you remember all stuff. More or less, more
145:53 less. Yeah, there's a there's , there's one key component that that's
146:04 here that most people will generate these size programs but they don't really understand
146:12 the process is to go from depth the log to time because all these
146:20 , as you can see, started in depth and remember our echo is
146:29 time. So we have to and as the reflections are coming from deeper
146:41 , they take longer to get So we know that there's some kind
146:44 mon atomic mapping between the depth of interface and the time that we get
146:54 . So the question is how do , how do we figure out that
147:00 ? Mhm. And the way it's is very simple. It's strictly from
147:09 sonic log because the sonic log told how long it takes to go across
147:18 interval. So we were looking at these logs that were in microseconds per
147:25 or microseconds per meter, that sonic has told us how long it takes
147:31 vibration to go across a foot. you can see that we've got the
147:40 log, which is how long it to go across a foot in
147:45 So we basically just add that. I've got the well log in depth
147:51 every foot I know how long it to go across the foot. So
147:56 here I add the number of microseconds . I add a number of microseconds
148:02 . I add the number of So I've got depth and travel time
148:11 from adding the cumulative transit time that know from the sonic log and that's
148:19 you do it. And that gives a depth to time mapping. So
148:27 with that I can stretch all the logs into time. And I multiply
148:32 by two because the seismic is not one way it's going down and
148:39 So to any given depth I've got have the size of going to go
148:44 to it and then back to the . So I get a mapping from
148:48 to two way time T. T. And then I changed all
148:52 my well logs into two way So now I've got my well logs
149:19 a time and the vibration of the of the vibe or the dynamite explosions
149:25 time. So now for every one these reflections or acoustic impedance changes,
149:33 just add on the wavelet and then all that together. That's going to
149:38 me the response at the well location a seismic seismic wave and that's what
149:47 call the synthetic or the simulated or theoretical or the manufactured size my
150:02 So now I've got a mapping between rock properties in depth and the rock
150:10 in time and then I shook all . I've got all these bounces coming
150:14 from everything and that gives me my or my computed size bigger which is
150:22 now called a synthetic or a manufactured . So once again we're gonna take
150:47 density login depth, the velocity log depth multiply them together. That gives
150:58 an impedance log in depth. I'm to stretch that into two way time
151:12 then add a wave lit for every activity through the process. Convolution.
151:18 is just replacing this spike with the lit and adding it all up.
151:23 then I get my final synthetic size . So once again get my logs
152:02 depth creating impedance log, stretch it time. The change in impedance or
152:11 impedance is the reflectivity hang a wave on each one of those reflectivity
152:15 And I would put that's my synthetic program which is my anticipated seismic response
152:23 that. Well, log geology so was in principle. Now we take
152:45 real log and this is my real log in time, calculate the change
152:57 impedance from the impedance. Get my log involve that or put this wave
153:04 on every one of those points, it all together and here's my anticipated
153:15 response. So there are a few that that we can see about this
153:43 one which has more detail the seismic or the well log. Um I
153:55 like the well log has more but seismic response is more legible.
154:01 definitely. The, the seismic response been banned limited. It's been an
154:06 and it's averaged the, the which gives us an average kind of
154:15 of the well long. There's a more excursions here. This is a
154:25 average view of the reflectivity and of well lock. Yes, the well
154:32 has a lot more detail. The is going to capture the very gross
154:40 of. So if I look at big change here, there's a big
154:48 in velocity density. Big I come here. I say, yeah,
154:55 a big change here. So the is definitely feeling this big guy.
155:01 know, it gets a bit complicated . You can see the seismic as
155:05 response. It's got a response to decrease. You know, there's a
155:14 increase here. We can see that a big decrease there. We can
155:18 that. So the major, the characteristics of the, of the
155:26 we're capturing that in the seismic, little details can, and I see
155:35 particular little layer there. Uh, not. So the seismic resolution is
155:47 less than the than the log. , this simulation is this is what
155:55 would see from the surface down. is actually what we've seen when
156:00 when we drill it. So that's synthetic size program. This, this
156:10 a very important tool for us and is what interpreters rely on to understand
156:16 sections. So we've got all this going on. We've got maybe some
156:23 and reports maybe a well or Then we've got and we've shot all
156:28 seismic and we've processed it. But I've got the seismic wiggles and time
156:33 the geology and depth. And I to tie those two together. And
156:39 the job that a lot of people this city do is they're interpreting or
156:44 and tying this story together, taking these measurements and putting them together into
156:50 interpreter. Ble story that here's what know about the geology. Here's what
156:57 know about the rocks. Here's what see from our seismic and here's my
157:03 of the seismic in terms of the properties and instantly I've interpreted and here's
157:10 bullseye drill here. And this is you can expect. So that's really
157:18 what this is about. So we're more and more realistic, this is
157:23 real log. This is the real . We've stretched the time using the
157:30 log, Transit times per foot in time. I've convulsing or hung this
157:38 on every one of these points as by the reflectivity summed it all together
157:43 the result is this which is really filtered version of this, which is
157:50 differentiated version of this. Mhm. that's the whole process. Good.
157:58 so what does that looked like? , we can we can go back
158:06 my well log. So here's a log, a velocity line. I
158:13 these together to get my impedance And then I have taking two microseconds
158:22 foot and created these logs and plotted out in time from the surface.
158:34 there's still a mapping between the But now this is plotted out in
158:38 . But for every one of these there's still a depth. But you
158:42 see that this scale is not This scale is now uniform. But
158:51 the relationship 600 milliseconds deep is the way travel time to 500 millisecond,
158:58 m from the surface. So just to sex, I'm just gonna put
159:03 my my blinds here. It's getting . My work, my workspace faces
159:39 . And so the sun to bake room. Okay, so what we've
159:51 is uh this is a classic display there are lots of software vendors who
159:56 this kind of software and manipulate And so once again we want to
160:04 this. We have the original logs depth. We took the microseconds per
160:10 for every foot. And every foot assigned at the two times the microsecond
160:16 transit time. So effectively stretched these into time that we can involved the
160:23 with this little wave lit and you see the wave lit. And then
160:27 out putting this blue synthetic size And then I'm comparing that to actual
160:37 from a seismic line and that's what do. So here you can see
160:44 real field seismic in black. And we've taken one of those field seismic
160:52 traces made it red. And then the synthetic size program which is in
160:58 . And we can look at the between the synthetic seismograph and blue and
161:03 real seismic and red. So what you think? Um I mean it's
161:15 close. The red is of course little bit more like the blue isn't
161:21 um pronounced I guess like it's like higher amplitudes and the red like aren't
161:30 high in the blue. But I it's close. So there there are
161:38 small some small differences. Like in the character is different through the play
161:46 . The character is pretty good. is a little bit a little bit
161:55 here. Got this reflector that So that's good. So what I'm
162:04 interested in the in this particular I'm interested in this area. And
162:08 the the character matches pretty good. actually theoretical correlation is okay but not
162:15 . So this is this is a negative indicator. It's pretty hard on
162:19 . It says it's only 0.7 which probably a little a little harsh.
162:29 what are we doing with this? the idea here is we've got a
162:33 drilled, we've done all of our physics. So we understand the,
162:39 we create the synthetic size program. so now I can understand the surface
162:47 and that's a big part of So this might be part of a
162:52 . And I'm gonna pick the time this surface, such as the
162:56 That's the colony sandstone. So I'm in that and I'm going to take
163:03 whole line or volume and with this wiggle, I understand that wiggle and
163:10 believe it because I've seen the well , I know that I know that
163:14 well logs have these characteristics. I the synthetic size program. I can
163:21 its character tied to the well logs that character in the synthetic is quite
163:26 to the character of the real So I kind of believe all this
163:32 , then I'm going to pick the of this horizon, the colony and
163:39 look all over the seismic volume to it and look at its character.
163:44 deep is it doesn't have any structure it. Do the amplitudes get bigger
163:49 less. So I'm going to look all those characteristics and then try to
163:54 up with a story for this colony . It looks like it's getting more
164:00 here, It's less porous here. think I can see the effects of
164:04 here and not here. And so going to do all these games with
164:09 , changing the seismic a little changing the well logs a little bit
164:15 seeing what that does and then trying find areas that might be gas saturated
164:22 example, or oil saturated in this horizon. And this is a big
164:30 . There's lots of colony gas around it's uh it's not deep, it's
164:35 1300 ft deep. So if we find that again, we can drill
164:40 and produce it cheaply. And then that's what we're trying to do.
164:46 that's the role of the the well in helping us understand surface eyes.
164:56 . So likewise if we went back this guy, this is kind of
165:01 stuff together again. Let's do a interpretation of these logs. So we've
165:11 this 10,000 ft. Well now I've you a few little highlights here.
165:24 we just do our regular interpretation Okay um caliber looks good. Um
165:33 that top section we have that low and lowest piece. We have some
165:40 and low radio activity. Um Then go to the reason festivity and we
165:51 high resistive Itty. Would these be of like no I was gonna say
166:00 sand because it's like fingers. But , they're definitely stringers because you can
166:10 that the S. P. And gamma ray oscillate back and forth.
166:16 it looks like a sand shell And then the resistive Itty is doing
166:24 little bit likewise. It's oscillating all the place, there are four or
166:28 strong fingers there. Okay I was say and then when we go to
166:38 atrocities, the neutron and the Um we would be looking at oil
166:51 I mean there are some crossovers in . But the way that they're not
166:58 like that top section. Um I think that that would be oil by
167:02 carbon. Yeah, the you can that there, there's definitely crossover
167:19 And so it it's not huge but definitely some. And we can also
167:30 that the delta T. The sonic are getting more slow. So we
167:39 see that there's a bit of a indicator up in the top now,
167:44 towards the bottom. Um it looks the velocities are a little bit
167:52 And I don't see maybe quite the but there's a little bit of
167:59 There's a little bit of crosstalk So that's why I evaluated this is
168:04 some gas and some oil. It's a little gassy at the top.
168:11 expect. You can see a nice right there. So that looks that
168:20 definitely gassy down here in some of other resistive intervals. It's not quite
168:29 obvious that that's pretty close. So might think that as you would imagine
168:37 bit more gas saturated on the bit more oil saturated the bottom.
168:43 the sonic logs are a bit slower type, which says probably gassy.
168:54 . But then as you go a deeper, what happens, what happens
168:57 here as we go deeper? Like we go into that next column Organa
169:05 , Go up a little bit but we go back down so we have
169:10 low gamma. Um S. Log goes way down so that's like
169:18 permissible. Um And then when we to the resistive Itty it's lower
169:28 So high conductivity. So that's indicative that brine. And then when we
169:37 to the density porosity there similar. that's also indicative of the brian.
169:47 love water. And then underneath that see caliper still looks good. Then
170:04 go low gamma. Again low SB still pretty were lower residence activity than
170:17 brine. But it's not as low what we would see up there in
170:22 sand. Yeah when we get below it's it's a bit of a mixed
170:30 . It's sand and shale. There's a good sands down here. But
170:38 can see that they're all pretty Yeah the rock is getting faster so
170:51 kind of pure brine saturated and and course the the processes are getting a
171:01 bit lower so it's getting faster. this is another good example of just
171:09 interpretation. But now when we move to thinking about what would seismic.
171:15 if I was interrogating this from above I was getting echoes. But with
171:21 mixing. And what we're gonna do multiply the density log times the velocity
171:28 and build our impedance which would have lot more character than this. I
171:32 did this by hand. So but general we've got a bit of a
171:37 impedance area here, going into higher back to lower impedance. And if
171:47 just did simple reflectivity, this is negative change of impedance. So I've
171:53 my negative reflectivity. This is a impedance change negative and positive. And
172:00 if I took a short wave I could hang the wave lit on
172:08 one of these guys added together. this is the kind of response that
172:13 would get from seismic. Okay, could I see the four fingers
172:21 No, I can't but I can the top of it. And I
172:26 see a bit of character here that you've got some kind of oscillations going
172:31 here when we hit the brine I can certainly see the top of
172:39 . And I probably can see the of it. So I'm gonna interpret
172:43 trough peak as the top and bottom my grind sand. So that's that's
172:51 I would be looking for. So is the this is the concept of
173:01 synthetic size program and we'll come back that. But now we've again we've
173:08 through the petro physicist lens that logs you've done your analysis to understand a
173:18 about the rock and the poor fill the process. So now we've got
173:24 and now we were set up to to extend that a bit more into
173:29 seismic domain? And the first way we extend it is to simulate through
173:38 these convolutional processes what the seismic would like. And this is a sketch
173:44 what it would look like. Um another case, you can see this
173:52 another real set of logs. So run through the quickly. The same
174:02 . Just tell me about this Sweet and then extend that into what
174:07 seismic response would look like. So don't you why don't you run through
174:11 guys too? Okay. I'm looking section A. Mm. I
174:21 nothing's really going on up there. We have high gamma throughout what's labeled
174:28 um sp There's really no change density being relativity, it's glower no
174:46 Yeah, There's nothing really going on there. Um Once we get into
174:52 , we get low gamma um sp also goes to the left pretty
175:03 Um Let's see, neutron. And the density. So we have the
175:09 that we like. Um going into , it's highly resistive. P wave
175:17 a little bit. Um density also . So that's indicative of gas.
175:27 And then, so then if we the density times the Z. That
175:34 give us. So since they're both , would that be a low,
175:41 if we're multiplying. Wouldn't that make a positive? Uh Well, they're
175:49 both positive numbers and so when we I see okay so it's the numbers
175:54 . Not necessarily. So the density positive. The positive multiplied together.
176:00 gives the impedance they're both positive even they've decreased they're both still positive but
176:11 so no we're not taking them We multiply them together first to get
176:14 impedance and then we'll get the negative the impedance log. Okay Okay so
176:24 yeah so then that multiply that that give us that kind of square sticking
176:30 to the left because they were positive that would give us pharaoh we do
176:35 wave lit that would be going out way. So then when we go
176:41 C. Um gamma is still kind high. No well it's starting it's
176:51 high but it's going the other direction . So it's decreasing from the high
176:56 was in B. Um the I'm sorry low so it was low
177:07 then it's starting to get higher from . But not much but not
177:13 Yeah. Um And then the P. So we're going down and
177:23 . The densities are now switched. that would be so we have less
177:40 . And then and then we look resistive. Itty and the permeability is
177:46 kicking to the left so it's still permeable it's okay so I was looking
177:55 that it's getting less permeable? So not, right okay so it's still
178:00 . Yeah. Okay that that shoot bright pink curve is still it's more
178:09 in the sea. Mhm. Now comes back a little bit but the
178:18 thing is B. C. That's a whole unit that if you
178:23 at the gamma ray as well as sp you can kind of see that
178:28 a whole unit. Yeah. Okay B. C. And D.
178:37 whole unit of sand. Okay there's little changes in it but basically that's
178:44 whole unit. Okay. Okay so so still and see the densities the
178:57 are not crossing over anymore. They crossed the other direction. Festivity were
179:02 high resistive. Itty so happy about . What's the so probably oil.
179:15 And then P. Wave let's see got a little they're increasing so they're
179:24 slower. Well look at the scale see 1000 to 400. So it's
179:35 £2000 as we're going to see is getting faster or slower? The transit
179:48 is getting faster. Well look at at the P. Wave. Look
179:54 the scale up there it's in Oh okay so then it's getting
180:09 Okay but relative to so relative to it's getting would it relative to be
180:20 getting faster. Yes. Okay so faster yes. Okay. Um It's
180:34 dense than B. Was so then it we'll be was, oh I
180:47 reading it the right wrong way so getting it's more dense Cosby was like
180:55 it's a little it's a little more than B. Was. Yeah.
180:58 that make sense with your interpretation so ? Yes. Yeah. We're going
181:04 gas to oil. Yeah. So then when I multiply so that
181:19 Mhm. So if I multiply why would it be then negative right
181:28 that positive that we have for? you said going from B to
181:38 the P wave is getting faster. getting more dense. So the product
181:48 those impedance is higher. Right? . So we plot the impedance
181:55 Guess B. Two C is getting . It's getting higher. Okay so
181:59 why we go the other way. why it's going to the right
182:09 okay. And then when we do wave look don't go in the other
182:15 . Okay so the reflection remember is change as we go deeper. So
182:25 change in Z. Be the change our block blog. This is just
182:30 make it simple. We go into top of B. We're going from
182:34 impedance to lower impedance impedance is are positive. But the change in the
182:41 , the reflectivity is negative. that makes that makes sense.
182:45 It's the change in the appearance, appearance itself multiplying density times velocity is
182:51 . They're all positive. There's never negative density and there's never a negative
182:56 . So they're always positive but the can be negative. Okay that makes
183:02 . That's always like what we're talking numbers. Okay, that makes
183:06 So we've done our little impedance log I just blocked it there simply.
183:12 then moving down the change in the log can be negative or positive.
183:16 our reflectivity. And you can see the simple arrows and then we wave
183:22 on top of that and that gives more or less are synthetic sizing
183:28 Okay, so what I would expect off the top of that sand,
183:35 going deeper from the A. Section be A. Is kind of a
183:39 E. Shelly stuff. Then I into a very clean sand at
183:45 Which has gas, so it's lower and lower velocity. So the impedance
183:53 smaller. The reflectivity is negative because got a negative change. And I'm
183:59 get a trough off the top of . So my seismic is going to
184:03 a nice trough off the top of gas saturated sand. Then just right
184:13 that going from B to C. going into a higher velocity high density
184:18 saturated. Mhm. And I can see that so I can see a
184:25 bounce off that and then not And then at the bottom of
184:32 I get another impedance change and so like to see a positive bounce off
184:39 very simply, that's that's more or the interpretation. This is a real
184:46 . This is a as you can a gas and oil reservoir sitting on
184:50 of the water in a in a water layer. Um simplifying the impedance
184:56 , which we would construct from the and velocity and getting the reflectivity and
185:01 getting the seismic. This is what expect to see. And so I'm
185:05 to go looking through all the seismic try to find that signature. So
185:13 once again tying us into all this . Okay, good. Yeah,
185:19 that's great Stephanie that we got through lot of stuff today. So that
185:24 of wraps up a stab at the physics. The well, logging gets
185:30 into the seismic world. So we're look a little bit more synthetics and
185:34 go into borehole seismic. Okay, . So have to meditate in
185:42 There are lots of, there are of well log sweets. I would
185:47 try a couple of them other areas we haven't, we haven't looked
185:52 If you have any questions about any those logs and doing it. Just
185:56 me a line and I'm here next . So we'll go through, we'll
186:04 have a little quiz friday, like an hour or something. Okay,
186:11 have a little quiz friday and then got saturday to do some more and
186:17 it's just the uh, another wow. Okay. Okay. So
186:32 gonna do in person on friday. yeah, maybe that's maybe that's a
186:42 idea. Um, That's March Yeah. Why don't we do a
186:56 in person session on friday. And then and then the rest will
187:02 just online. Okay man, I think I've taken an in person quiz
187:11 Covid. Well I won't I won't there. Well we'll let you do
187:19 . It'll be just it'll be a short quiz. You can just do
187:22 . It's um and there's no there's ultra time so we'll just it'll be
187:29 a little log exercise. Just exactly what we've done. Yeah, I
187:34 just thinking that I was like, , I don't think I've done it
187:36 a long time. Yeah. Yeah. I know for a lot
187:44 people it's been a long time since even talked to anybody in person.
187:51 , I don't think I've taken an person exam, just like a test
187:55 . I don't think I've taken an person exam since spring of 2020.
188:00 sure I'm sure I can remember We had a birthday party, March
188:06 of 2020 and that was the last that a whole pile of us were
188:13 to get together in person for, know pushing, pushing a year and
188:19 like you there were all kinds of and friends of mine, some were
188:24 of more liberal and we started meeting of us who are a little bit
188:27 adventuresome but many good friends. Didn't anybody basically for almost two years.
188:36 , it's just such a, an time. Yeah, I worked,
188:44 I was still going to work every . But it was very weird cause
188:48 worked with seniors. I worked at senior apartment community and we had to
188:53 like masked up just because they you know, the population that was
188:56 hit the worst. So we had wear PPE and stuff to go to
189:00 and stuff like that. It was . Well that it was really
189:06 you know, in Spades, it , it was really scary, especially
189:09 seniors, really scary. You there was, there was one of
189:17 nursing homes in my home in my because my parents were seniors at the
189:22 and the, you know, covid to the nursing home and I think
189:26 killed two thirds of, you 100 or 200 people in the nursing
189:30 was just horrible. That was just of the worst cases nationwide. But
189:39 , we made it through largely. actually didn't get Covid until last
189:50 I I went through the whole I was just fine. And then
189:54 got Covid in july of 22. I was just like, it was
190:02 like, I was like, I went this whole time getting it
190:04 . I got it. Well, think you waited until the right
190:10 Yeah, my grandmother actually passed away the, I call it the original
190:15 . So she died from Covid back january of 21 um she passed and
190:24 , yeah, we all didn't get until 22. So I'm sorry to
190:28 about your grandmother. But fortunate that the rest kind of toned down
190:36 . Oh yeah, for sure. was sick for like three days and
190:39 I was fine. Yeah. I it in january 22 also and I
190:47 the same way you did. I , wow, I've avoided this whole
190:50 and I wasn't being cocky about it . I mean, I was actually
190:54 of the country when the vaccines came in 2020 and I flew back here
190:59 january 2020 to get that vaccine well, actually, I guess that
191:05 2020 21. As soon as the was available, 2021 I flew back
191:12 they had the big lineups here and call in and try to get the
191:15 . And so I was I was happy to have got it because
191:20 everybody just thought, this thing is fatal and we have one chance to
191:27 was pregnant when the vaccine came out they didn't advise me to get
191:31 And in the beginning, they said women shouldn't get it. And then
191:35 the end and they're like, you can get it. But I
191:38 already, I was like, what changed between me being able not
191:41 get it and then to get So it was a very weird
191:45 Well it is and and you know as from a scientist point of
191:51 I was a bit more tolerant, guess because guess what? Nobody did
191:58 what was going on. It was new virus and none of us had
192:04 through a pandemic for 100 years. one was the spanish flu. So
192:09 frankly knew what the hell they were . And the thing is that like
192:16 , the public wants to know what doing, but that it just wasn't
192:24 like pregnant women. This vaccine, . R. N. A.
192:29 were so new and so radical that knew what they were going to do
192:37 people who are not pregnant people who pregnant carrying another life that's rapidly changing
192:44 them. So, you know, think I'm in the sector that I
192:50 that this was a miracle that we anything that would help us for
192:56 but nobody knew what the effects were be. And all of us rolled
193:00 days. Everybody was scared, everybody's the solidified horror story in their
193:08 So nobody wanted that. And so thought, you know, it's it's
193:16 bad that the medical community doesn't really . But um you know, we've
193:20 drilling wells finding oil and gas and miss all the time. So we
193:25 do better. Yeah, that's So anyway. Well, I'm glad
193:31 everybody is uh that you and the while we're healthy, in any
193:37 Mhm. Oh good. Okay, , great Stephanie. Uh well we'll
193:45 you friday and I think in person is a good idea. Okay,
193:53 . We'll see you next friday. right, thank you so much.
193:58 have a good rest of the
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