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GEOL6393-Seismic Amplitude Interpretation - Day3 01-26-24
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00:01 What this, it is a lot sandstones that they measured fall between his
00:12 limits and the best fit. So best fit is not the hill
00:20 but it's close to it. Sure . I, we're gonna have to
00:25 it by another way. How about poor fluid? Well, in the
00:33 fluid, I wrote this as we a suspension of solid in the poorest
00:44 with water and hydro grams. I crossed out the solids such as
00:51 if he had clay in the wasn't touching anything just sitting in the
00:57 . Well, you have to account , but we normally don't. So
01:00 we do is I just crossed out feed and this gives us a method
01:06 ahead and getting the bulk modulus of poor floor in terms of what's the
01:16 and what's the hydrocarbon. What, do you like? Now the Brian
01:25 mo your life and the hydro car it gas or what we get from
01:36 article by that and why? And give you the article in the articles
01:45 read, it's gonna take a day so to read it and to digest
01:56 . And that's the hard way. easy way is to knock at the
02:03 beginning of my book that I gave a copy of and it tells you
02:09 people whose books to get one is Asma and the other one is Gary
02:19 . Yuri Mao's book is the book program from. If you want an
02:25 spreadsheet. You wanna do this in , you want Gary Maa's book because
02:31 gives you all the parameters that you for doing Petro physics. It's an
02:39 Petro physicist book. That's those And that are just a small,
02:46 part. Here's an example of applying equation here. So what's the bulk
03:02 of the fluid? If I have gassed, that would be way up
03:11 . It's all gas. This is . So water here and gas over
03:19 . If I have the pores in water, I have a bulk modulus
03:26 two gigas. But by adding just little bit of gas, 5 10%
03:35 stiffness of the poor load decreases And it gets done to like 0.03
03:45 out here. Say it another way does not like to be squeezed.
03:54 does really not like it, it the bulk modules of two that's
04:00 Gus doesn't give a hoot, you squeeze gas and it's 10 times L
04:08 that of the um water. So you have a little bit of gas
04:18 water, you could squeeze it little being 5 10%. But after you
04:28 in the initial, you can put the more gas you want to.
04:31 not gonna change much. Once you it, you got it, you
04:36 do change it much more. So gives us what's called the little bit
04:49 . And when we read these, kind of ones you wanna remember.
05:00 the thumb, the blue and the are the only thing that's gonna change
05:07 this particular, it says sheer the first few percent of clay have
05:17 largest effect on the sheer margins and additional amount of clay results in less
05:25 less of a drop in she What is this? She modulus if
05:37 wave is going that way, which the particles moving up and down?
05:44 , if I have a share I mean, done, it's coming
05:48 do do do do do but the are going like this. The particles
05:52 because they can't have a sheer wave air, but they can pretend particles
05:57 going like this. So the particle comes down and it hits my grain
06:03 sand and that grain of sand is on top of another one. Sure
06:09 it comes down. Do do do it. It's just uh it
06:13 hardly move one grain against the So we take it off, put
06:18 little bit of slippery clay in between grains and we bring it down
06:23 Do do do do hits that, who it slips real fast? It
06:28 takes a little bit of clay between greens to make them slippery. And
06:34 that reduces the sheer marginist sheer margins the resistance to move back and
06:44 Any amount of clay results in less less a drop in sheer modulus.
06:55 , the famous saying from the bright here, this is the late
07:02 19 seventies bulk modulus. The first percent of gas have the largest effect
07:12 the bulk modulus and adding any additional of gas results in less. Unless
07:18 drop in bulk modulus C sponge, squeeze that, you keep squeezing,
07:31 gonna have the same strength. You it one time, just a little
07:35 of gas. That was this slide here. You add a little bit
07:41 gas going from here to there There they go some two way
08:07 I think this is right by Lake and the red indicate gas. And
08:25 would say these are mud lumps on surface and are charged with gas.
08:34 they call these areas right here gas . There's no seismic data. It's
08:43 , very poorly illuminated. No, idea that the thought is down here
08:55 the source of the gas and it's leak upwards. Well, is that
09:04 leaking proportionally? Is it coming up like that until it gets in these
09:13 sands. I don't know. I an idea. The gas is gonna
09:21 little faults coming up like that. I don't think that shell has a
09:28 of gas in it and I, don't, I don't expect this to
09:33 one sloppy soup. But how about surface? That's different? You have
09:41 sand up there. Very shallow sand it's gas charged. What's the
09:48 You can have shadow sands down here the gas charge? Look, here's
09:52 right there. Why up here does blanket up all this data underneath?
10:04 is the velocity inside a shallow Sam? Where are these slides
10:17 Uh Fred, I, I don't these slides in our slide deck.
10:22 you in the summer slide deck? , you're not seeing any slides at
10:27 . I've seen your slides, but don't see them in our version of
10:31 slide deck. Is this still You haven't been seeing any slides at
10:38 ? I have been seeing your I'm I'm following along in my slide
10:42 to take notes, but I, don't, what are you in a
10:46 slide set? Are you in 2.1 ? I I'm in 2.1. Does
10:53 else have these slides? No, a second. Ok. I'm in
11:37 . But the fever is that five students. So they mentioned that uh
11:47 put all the figures in one slide we covered the PDF file the figure
11:53 that will be overlapped. So they see. This is my PDF S
12:21 , the PIAs have been shown What's that? It stops at 97
12:37 . Is it only five 96? ? That's mine does too. And
12:51 2.1. Say that again. Little bit. Th can you hear
13:40 anybody over there? No, you hear me, we can hear
13:44 We're just not looking at your OK. Do you have the slide
13:51 a little bit theories that talk about sheer modulus and the bulk modulus?
13:56 , we have that one. Well, looks like, OK.
14:09 , this is the PDF and it like you are right. OK.
15:23 . I think I know what What I did is I had,
15:36 had hidden slides 94. It was a certain point. I made the
15:42 and then last Monday when I was to see what I was going to
15:49 today, I took those hidden slides made them active and my new PDF
16:03 I have generator. If it slides , it doesn't generate it. My
16:12 one did, but the old one lost when U of H lost her
16:19 with Adobe and I had to buy own and uh I didn't, I
16:26 realize, yeah, then realize that can't, it, it works
16:33 I apologize. Let, let, me show it anyhow. It,
16:42 , it it has some interesting, results that I think you, you'd
16:52 interesting in hearing, uh, if , if you ever do exploration in
16:57 little place called Gulf of Mexico, , especially around the bird's foot dealt
17:06 . Can I, uh, let's what happens. You see my
17:16 Yes. Yes. But we're in presentation mode if you care.
17:22 they have to duplicate it. How's better? Every time he runs
17:37 he hits different buttons. So I it's not nice to treat all people
17:46 way. Ok. I think this like Geneva, uh the home of
18:00 Rich Arabs uh as Geneva, it's their party party place. The question
18:16 , is this all of these all filled shales sitting in there and surely
18:25 has to be gas sands in What, what's happening? So we're
18:30 look at the velocity of a shallow lamp. What's the velocity in
18:40 What's, what is the sound velocity air? Anybody know 300 m per
18:52 ? 1100 ft per second? good. What's the velocity propagation velocity
18:58 water? What? 1500 m per ? 10,100 ft per second. What's
19:12 velocity of a water saturated sand just the ocean bottom? Shallow san 5200
19:23 per second? Something like that. what would be the velocity of a
19:32 gas s now remember air or It's 1100 ft per second?
19:42 saturates, sand is 5200 feet per . Water velocity 5000 ft per
19:55 So I did 11 1,010,200 good 0 2000 ft per second,
20:05 Maybe, maybe, maybe. Let's look at the mud lump rock
20:13 . Mud lumps are these shallow volcanic of eruptions at ocean bottom and they
20:24 these lumps of mud that are really in gas. Then they get buried
20:30 little bit. They still have these saturation. And here's the properties
20:44 of brine, its density Brian gas the quartz properties, water saturation has
20:53 lot of water. Only 20% Bach modulus, the brine, you
20:59 it up in the tables. Batsell Margs of gas, look it
21:04 Bach Mars courts all come from bats Wayne. We put it out,
21:11 this equation together to find what the modules of the fluid is. The
21:19 rigidity of the fluid is zero and density of the rock is 1.54.
21:27 look at the property of the P velocity. And if you take the
21:34 modulus, uh it's gonna be And that happens to be this bulk
21:43 era divide by the density. And we get what we get is something
21:54 doesn't show what's gonna happen when I this off again, I wanna get
22:09 . You must have sit over This is oh mhm. The
23:03 Yeah, the bottom line is the and the shallow sand is 340 ft
23:24 second. A little over 100 m second. That it's unreal. A
23:33 Exxon used to shoot down in Lake , Venezuela. They went down there
23:40 the 19 sixties wrote an article, think it's geophysics and they measured the
23:48 velocities and they got pretty much close the same thing. 300 ft per
23:54 . Texaco did the big effort around birds for delta and they got about
23:59 same velocity of the shallow sands. , why, why were they so
24:09 ? Because the reflection coefficient is 0.91 , hardly any energy goes through the
24:18 . If you want to get to sand, the energy has to go
24:23 . It come at this point in bottom and then propagate as if this
24:28 . That was a point dra a in 1972 I took a mobile research
24:40 offshore birds would dealt them. We a cable, ocean bottom cable,
24:48 water about 40 ft and it was uh a quarter of a mile
24:57 The ocean bottom cable and we dropped off the edge of the at the
25:04 of the boat about every quarter of mile and got was called a noise
25:12 when we came back in and put in the processing. Each one of
25:17 1234 is a dynamite. What's the k, 20 stations in the
25:28 And you can see they look like are nice patterns inside, but big
25:35 shifts between them. And here's what was happening as we were detonating every
25:45 every 330 ft. Excuse me, energy from this shot way over to
26:03 , when this shot went off, , no energy goes through. Energy
26:10 down, here comes down to And that point right there acts as
26:15 new energy source to send energy out the travel path in order to
26:28 in order to get energy at this , say up the top of
26:36 they could just go straight down, problem whatsoever. But to get to
26:41 , you had to have energy comes here. It will come up through
26:49 and then to the cable and it propagate down. It, energy could
26:54 down it here up to this edge then propagate to the geophones. It
27:02 doesn't go through the sand. And remember I had this on my office
27:14 and in comes the divisional geophysicists because beside it, I had that.
27:22 he says, how did you get ? And I says, well,
27:25 is a paper plot that they give us out of the lab and
27:29 just took a razor blade, tied together and scotch taped it. He
27:34 , no, that's what I call geophysics. And it looked like
27:38 just because they could program it. , that's, that's geophysics.
27:42 my son. Ok. My But the idea is, again,
27:51 can't get energy through it. It around it. And that was a
28:01 difficult problem to solve. And some the labs like Shell had a solution
28:12 a company called GEOS signal are a good shit out of. Stanford wasn't
28:20 kid. Went to mobile and he it in rage, tracing it.
28:27 a beautiful job. And GEOS signal reprocessed hundreds and hundreds of blocks or
28:36 gas in was race racing like doing a depth migration following the ray pass
28:48 . Nobody could do it but just western Geophysical block, GEOS signal.
28:55 don't know what they paid him probably million $60 million. So they own
29:01 software. Now, you ever, ever hear of it? And the
29:06 ? No, they buried it. too expensive to run. Takes too
29:12 human time to run it and it with their flow of spec data that
29:18 trying to get through quickly. So die at a big program at 5000
29:36 depth. The poor fluid and the reservoir, it's easier or harder to
29:46 than the poor fluid and the gas at 25,000. What is the bulk
29:56 ? List of gas at 5000 versus at 25,000? Thank you. Here's
30:20 equation we're gonna use. We go to bats on Wang. They'll give
30:29 with the brine and hydrocarbon B moduli . We plug it in the,
30:36 equation here and we see at 5000 depth, the bulk modules in the
30:42 fluid is 0.066. Now compare this here to Brian right up there.
30:55 a big difference. It says if put gas in the reservoir at 5000
31:03 , you're gonna have a significantly different modulus. It's gonna be very easy
31:11 squeeze that gas when it's at 5000 at 25,000 ft, the bulk modulus
31:24 gas as almost in the same order magnitude is the bulk modulus of
31:32 And what does that say? It at 25,000 ft, all that pore
31:38 is squeezing the gas so much that makes it bulk modulus very rigid.
31:47 what does that mean? It's more to see gas reservoirs at 25,000 ft
31:55 the pressure is increasing the bulk modulus the poor fluid, especially when it's
32:02 oil a little bit but not as as gas. So all those nice
32:08 spots, large amplitudes that you see shadow kind of disappear down deep.
32:26 a couple other things that we need , to know. One is what
32:35 API that's the gravity of oil at surface. And it's given a specific
32:47 like that's 32 or 34 to give a number, the bigger the
32:55 the lighter it is around 12, the, the weight of water start
33:04 bigger numbers. You're starting to get inside the uh horses pacific gas
33:14 That's comparing your gas density to air 0.7 typical number. Very important diaspora
33:26 . That's the amount of gas that dissolved in oil for given pressure,
33:33 and composition of oil. This is toughie because they tend to give you
33:41 gas or ratio at the surface. that's not really right. And so
33:49 a little difficult to get the gas ratio, but it's a very important
33:54 that comes from our reservoir engineers, gas or ratio. This is the
34:06 maximum amount of gas that could be in oil. If you, if
34:14 do not have a gas cap and have oil, that means you can
34:20 put more gas into the oil, is not reached its maximum. If
34:27 have gas cap, that oil is maximum value. And there is an
34:35 that tells you what it is. in the program tips that I gave
34:43 . If you try to put a or ratio, that's too big.
34:47 will replace it. Let's put it the maximum is. We're not gonna
35:11 that one right there for the time . OK? Well, we introduced
35:19 basic notation for Fritz Gassman. We've about him a little bit before.
35:30 geophysics in mathematician. He has a theory in topology named after him.
35:40 today, his work is still One of our research professors Leon Thompson
35:47 a paper saying that Gasman was He found an error society of exploration
35:58 rejected his paper. He sent it European Geophysical Society published it. He
36:06 a presentation, he got the best award because the significance of the paper
36:14 to be determined what the US will it or not. So,
36:20 more about Gasser, let's go ahead take your break for about five
36:29 And I want to see if I make my peppermint supposed to suck
36:40 I get peppermint tea for tomorrow. helps the drainage. No part of
39:54 , the, that was the last . That section wasn't it?
40:24 I'm ready to go. Ok, go back to Fritz Gassman. I
40:36 know his real name. The man the man who the theorized how to
40:43 gas in the water and write an for it. It was the gas
40:52 . I have to live with that a while. So, was this
41:05 that everybody knew about? How does stuff come about? In 1951?
41:16 published that article finished his phd at published it. She thought it was
41:25 neat, but she'll want always wants . And their idea was this take
41:34 bottle of water like this and think the plastic as being the grains and
41:43 scythe is in the forest. a wave comes down and pushes us
41:48 and down. But what if the comes down like that? Well,
41:53 water is up here and the plastics here, so the grains can move
41:59 than maybe the water. And when happens, the water rubs in as
42:07 , aside the pore throats. And anything rubs against something else, it
42:14 heat, viscosity is not zero. you start generating e you lose,
42:21 lose amplitude because you lost energy transferred heat. And so it depends upon
42:34 quickly you shake it. If you real slow, the water and the
42:39 remain the same if you go Wow. So it's frequency dependent.
42:48 they called this guy ha called Hey, b do you take Gaston's
42:56 and go ahead and allow the water move independently of the grains? And
43:06 says, OK, so he spent time brought it solved. It made
43:12 publications. Shell looked around and Mary, you're a top mathematician,
43:21 out of the research lab and teach divisions on how to use bio.
43:28 she looked at her boss and I have no idea what that guy
43:32 talking about. And it is very . When I was at mobile
43:40 There was a physicist sharp guy in office right beside me, it took
43:44 three months to read that paper and how he went from one equation to
43:51 next. Very difficult. Many people looked at it. Yeah. Shows
44:01 the Quran, what the heck do do now? So they, they
44:05 another guy and uh asked him to ahead, reach, read Theo's theory
44:18 get, hey, go ahead and it to people and he read it
44:24 reported back to management. He says got good news and bad news.
44:29 give me the good news first. said, geophysicists don't have to worry
44:34 him. He why he says, , bio's theory only is applicable when
44:41 get frequencies above 100 200 Hertz. said, so Jasmine's equation is all
44:47 have to know. It's oh thank you. He said, but
44:52 the bad news is your choice of is going to hate us because up
44:59 at 20 kilohertz, they better start B OS theory if they want to
45:03 predictions about rock properties because it's very them. Now, other things that
45:12 of pop up his white did a on it and he says,
45:19 what does this G really do when inside the pores? That Gaston's
45:29 We got Bio's equation and Bio's equation there's another wave that's generated. You
45:42 the conventional, we'll call it fast that travels through the rock, but
45:48 a small one we'll call the right? It's not very big
45:54 not at all, but that's And therefore you lose a little energy
46:01 the fast way because the slow has little bit of energy. Oh,
46:07 . So people started to think, , what would happen when you add
46:17 and it's different amounts? What would in particular one? That's around 15%
46:26 ? Why is it when you get that quote residual gas saturate? Why
46:31 it that all of a sudden big ? And Ed White went to study
46:39 and he theoretically said yes, there a gas bubble and when you shake
46:49 , water tries to get into the and that's energy that's lost. He
46:58 , but not the amount of energy you want to be lost to validate
47:04 theory you have. He said you need one big bubble, you gotta
47:11 a lot of bubbles. So if have a lot of bubbles in
47:16 it's just that will attenuate the I said, well, how many
47:23 it turns out you can get in range? 10 to 15% gas,
47:31 a residual gas. You get a of attenuation. But if you get
47:38 than that, there's no attenuation. you get bigger than that, there's
47:41 attenuation. And that's such a a previous that I made saying that whatever
47:51 get a lot of bubbles, more 15 20% the bubbles start to coalesce
48:00 , they start forming one bubble and what counts. It's the number of
48:07 that you have not how big they because it's that individual squeezing the water
48:14 the gas bubble. And when you too small, a number of
48:21 you don't really have enough to generate loss of amplitude. So why was
48:31 of the ones it's not on here uh help to find residual gas saturation
48:39 the attenuation. Amoco try to use in order in their shooting in this
48:57 Sea just beneath the water. In Red Sea, there's thousands of feet
49:11 an hydrate and shale, tremendous, loss of amplitude. When you have
49:25 than in hydrate, there's a problem exists called pretty good angle reflections.
49:42 wanna use, I wanna go to white screen again to see if I
49:46 do work. OK. Now bubbles and water. If you have
50:00 velocity of 20,000 ft per second here y of velocity of 5000 ft per
50:10 , there's a critical angle. That's arc sign a five over 20 for
50:22 particular case. And what angle would be? Anybody have a calculator?
50:47 14, 14.48. OK. So angle right there is going to be
51:01 . And so when a shot goes , energy comes down at 14
51:09 all of a sudden you reach critical which means no energy gets into the
51:25 , no energy gets into the subsurface than that cone of 28 degrees So
51:34 have 28 over a potential of 100 80 and square that. And that's
51:50 percentage of energy that can go into subsurface when you have these very high
51:57 contrasts. In other words, all energy massive amount stays up here in
52:06 near surface and just reverberates back and , generating surface waves. Amaco had
52:21 by the Red Sea. And so wanted to decide how can we stop
52:27 this energy from being trapped in the ? How can we kill it?
52:34 , we just got done studying Ed and his air bubbles and the air
52:42 . If you have a way of and it hits those, it doesn't
52:46 to go through it. It's like wall of, of cotton. And
52:53 what they did is they take PV pipe and put little holes in it
52:59 then they have their air gun sitting and they have, then all put
53:05 big ring of Plexiglas type on the on the ocean bottom and percolate little
53:14 bubbles coming out of those slots giving curtain then detonate. You're shocked.
53:22 the energy stays, doesn't go But how do you move your PV
53:29 pipe to the next location? How you pull the wall in the ocean
53:35 ? So great idea, but tough implement in the field. Now where
53:42 do implement it is when you have that are made out of mud and
53:50 was what happened in Italy, a of dams broke, they had
53:55 earthquake came down, got into the and it start building resonant frequencies.
54:02 just set up and in the water spots back and forth this earthquake wave
54:08 finally it got big enough to just the earth and dam away. So
54:15 do they do? Pipes on the ? They percolate ear bubbles up.
54:22 when the earthquake wave comes, it that air bubble and it can't go
54:37 . Ok, let's get back to famous. And what was the significance
54:47 this poor fluid substitution? What do want to do? You're a
54:55 Anybody ever see seismic data as a ? Yeah. Yeah. You ever
55:02 seismic data? Was it a dry ? And you're part of the
55:09 And you wanna know, well, would my seismic look like to that
55:15 Carbs? You wanna take that wall and do a poor fluid substitution in
55:22 to predict what size is going to like when a Cider crumbs? So
55:27 don't start with nothing. We start a well log and what are we
55:34 change? Only do one thing we're change the poor floor. And so
55:44 start with a very simple equation. is the equation for the propagation of
55:52 wave and the infinite medium homogeneous And this is Gassman equation and both
56:03 these pretty much the same, this is repeated down here. Only me
56:17 you what? It's the same doesn't K is the bulk margins of the
56:25 when it's dry. This over here the bulk modulus that you have to
56:34 if it happens to be water or fluid in there. So this is
56:40 term the gas unpredicted. Now, you look at that equation, the
56:48 thing is this is the only thing we're going to change. I know
56:58 P wave velocity when your water. ? So I'm gonna be able to
57:06 all these terms in here when it's wet. Then I'm gonna redo
57:15 All the terms remain the same except poor lord. I'm not gonna put
57:23 in here at 2.2. I don't put gas. It has to be
57:27 like 27.03 and that's going to change whole rock velocity. OK? Only
57:40 thing changing. So let's go ahead ask ourselves what's known and what's unknown
57:49 his previous equation? What do we ? And what don't we do?
57:56 still have that with all law curves done? Rochelle Gerald got the wet
58:03 . So you can give me the wave velocity density and porosity that wet
58:08 . Yeah. Take it right off log. OK? Can you give
58:12 the bulk marg list of the Yeah, it remember it's 85%
58:19 15% clay. Fine. I can the bulk modules of that by the
58:27 Root Hill method. Well, how the bach margins of the fluid?
58:33 , shell drilled it most of the . That's just water. So,
58:37 at the bulk mars of water, anybody? Nobody works for shell do
58:42 . Oh, ok. So we to find out what the bulk marches
58:48 float is. We do that using on the way. So what do
58:54 have? All these are known? got three unknowns, the bulk modulus
59:01 it's dry, the sheer modules from and the sheer wave velocity.
59:11 She wa velocity. We can log if we don't log it. We
59:18 Greenberg Assaga transforms that we covered. ? And there are a couple other
59:28 shown beneath there, but we're gonna either you log in or use green
59:33 usually the method that, that it's . What this is, is those
59:44 dare to tread upon water if if you can walk across water.
59:51 . Yeah. Did you know Jesus a geophysicist. You eat it.
60:01 know that anybody ever read the It's in the Bible? Oh
60:11 You don't think it is. Do if I tell you, what will
60:15 buy dinner for all of us OK. And if I'm wrong,
60:20 buy dinner. OK? Jesus with . And what did he do?
60:32 walked on water. Well, how they do that miracle? That's not
60:37 miracle. There's physics. Behind If you shuffle your feet fast
60:45 you create a shear wave and she don't propagate water. So you get
60:50 walk right across but moving your feet enough, the Bible tells us that
60:58 . No, I didn't, doesn't how fast you move your feet and
61:00 didn't say this either. Don't record . Ok. Um We have
61:14 We can get Kak, we, , every as I'm going down
61:19 this is the one it's program. can make an Excel spreadsheet. We'll
61:22 this real quick. What's K Well, that's the P wave velocity
61:30 four thirds of sheer wave velocity squared . And if you don't have the
61:34 wave measure, use Greenberg gag, what, then you compute cage
61:40 How do I do that? Everything this equation is up above. So
61:46 problem. Just plug it in Now, once you've got done finding
61:53 dry, you go back to this right here and say I now know
62:01 on this side here and I can P the row there. Only thing
62:09 need is a new dry route, new uh bulk marches for the poor
62:16 . And again, this is the Wang and he put that in,
62:22 Kam, you now saw Gaston's Let's take a look at the
62:42 Mhm It's kind of interesting in that have your dry rock and fluid portion
62:51 equation. And we, we're gonna reflections have a dry rock portion in
62:58 flow portion. Also, if I an unconsolidated rock, possibly about 33%
63:06 term right here. That term is gigas. If I go ahead and
63:16 the previous equations, I can compute right in here. And it depends
63:23 what I have there. If I water, if I put water in
63:29 , that terms 5.51 if I put in here, that turns 0.06.
63:38 forget about density. Uh think of concept, what's the P wave
63:43 Now, when it's water wet, add these two and take the square
63:49 , that's about 7.1 compared to what it when it's gas add these turn
63:56 ? That's wow, 7.1 square root square root of 1.69. 0,
64:02 difference. Yeah. So the P velocity will distinguish water from gas
64:12 Well, what if it's consolidated ro ft per second and density 0.05 voc
64:27 ? Well, again, play the game, put water in. And
64:33 term right here, if you put is 2.4 if you put gas over
64:39 , it's 4018. Ok. what would the P wave velocity be
64:49 it's water screw route? 77 versus root? 75 dang, 77 versus
64:59 screw root? That's gonna be man. No big difference. Like
65:03 why the big thing, the dry , look at the difference.
65:11 It sure is a big difference. look at these, the fluid factor
65:21 , you know, court sort of same order of magnitude difference. If
65:27 water. I mean, if it's pros or low prosy, it's
65:40 So, what did your ingenious mind ? You decide? Hm. You
65:47 what I can do? I'm very at algebra. So I'm gonna take
65:53 1.63 and put it on the other . So the minus here and an
66:00 sign here in the minus here and equal sign right there. No,
66:10 I can find an attribute, a attribute, something I can get out
66:20 seismic data to satisfy that. I'll able to tell gas from water that's
66:29 . Do we have this attribute? the answer is yes, we need
66:36 find out who that is. let's look a little bit more at
66:46 we just computing if I have 33% and there's my velocity. 8300.
66:56 is all water. This is all . I add a little bit of
67:04 velocity jobs quickly. Wow. if I had 8% ferocity starting with
67:16 like the limestone, I add a bit of gas. I go,
67:21 doesn't go, it just drops a bit. So you only get a
67:26 drop in velocity when you get those high velocities. So it comes down
67:35 the velocity of unconsolidated rocks is strongly by the poor floor. The velocity
67:44 well consolidated routes is not influenced by worth little time. It's influenced by
67:55 . Interesting. I think we had one here before. Yes, I
68:08 approach your company by the way on Monday. Yeah. Yeah. All
68:15 I would tell him hire me. . How are my students? They
68:22 experts and poor fluid substitution, but wanna say we're gonna test you,
68:31 know how they're gonna test you. gonna give you that roll up curve
68:35 we had that one will that had up at the top, sit right
68:43 the bottom and fizz in between. what they're gonna say is I want
68:49 to do a poor fluid substitution and want you to make the gas in
68:57 . We, I wanna see this what we got when we drilled and
69:04 . Now, I wanna know if was all wet, what would the
69:08 intensity look like? And that's given you right here by the red.
69:18 red happens to be the, what happen if you did a poor flow
69:24 ? And it's about the same as green down here is what you're trying
69:29 match and this red should match the blue there and above. So this
69:35 done or float substitution using the procedures as we went through the equations.
69:54 some of the things that we cover trends are based from the mud
69:59 ocean bottle. If you're in deep and you're trying to make trends,
70:05 do sea level, you gotta do bottle velocities and densities, consolidated rocks
70:12 affected more with ferocity and mythology variations poor fluid variations. Yasin's equation because
70:33 don't know of any other theoretical physics equations that withhold all the scrutiny.
70:44 if you wanna change poor fluids and have a ball walker, I,
70:50 feel fairly comfortable that I'm gonna be to correct. What if I wanna
70:57 the price? I'm stuck. I to have a method in order to
71:03 product. Now, I actually gave one, gave you an Excel spreadsheet
71:09 and all those Excel programs in order do that. OK. Velocity prediction
71:19 on poros of the environment. Basically a digenetic or is in a depositional
71:36 . Now, how do we do change the porosity? Mhm. Let's
71:49 at building a rock property cross If I look at porosity versus P
72:02 velocity and I just plotted what I through in this little text, I'd
72:12 these 12345 different, five different And that's not to mention the sorting
72:23 deposition that Stanford gave us, but out for unconsolidated rocks. Uh those
72:33 and depositional trends love the digenetic are good. And so what we gotta
72:41 is try to test that out. we have a theoretical model and validated
72:51 ? How do we validate it? we do it with well log
72:55 And so we're gonna use thousands of in order to validate these different ferocity
73:04 . We'll start up here. This the northern section of West Cameron
73:14 You're basically looking at all offshore data that's Texas over here in Louisiana.
73:29 here, we'll take 100 and 81 in there and each well, early
73:43 ft, we take 5000 to 5200 . And in there, we're gonna
73:52 at the shell and the sand We wanna know what's your velocity density
74:00 when it's oil and gas saturated y resistivity. Now give me your seismic
74:08 . You would compute your normal incense all that. So, h 200
74:14 , H 200 ft, you have 60 different seismic attributes and then he
74:21 the next 200 ft. So you're coupling the reservoir properties rather than building
74:36 . So here's an example, these the brine saturated sand velocity above abnormal
74:45 . Well, near if you bring well in where is abnormal pressure.
74:50 that's the, that's the time total , abnormal pressure only look at properties
74:56 to that. Then you look at below Amoral pressure. You can take
75:01 part of the world. These are average velocities, 1000 ft interval going
75:09 those. What 100 and 81 type uh wells. And it's a pretty
75:17 trend. Did you see there? this would be biogenetic? You're looking
75:23 different process, different aging, different sitting in there. Meanwhile, we
75:31 P wave velocity versus ferocity and this from 700 to 12,000 ft plots in
75:42 . The weight versus pros. Then say, OK, give me the
75:49 to 7000 ft range. That's this right in here. Then I
75:56 OK, in that zone right what I want every 1% in
76:04 every 1% is a go longer. want the average velocity. So this
76:10 the average velocity in the yellow It's a depositional trend, it's the
76:19 depth. This is the digenetic Now when I get done, here's
76:27 field data has given us. These all averages that we get from 100
76:36 81 wells from the deposition to the trend. Now, our goal is
76:45 develop a theoretical deposition and died in trend to match the field data.
76:57 this point in the middle is our point. That's the one well that
77:05 interested in. And rather than use uh here we go, these two
77:28 nongenetic debit, these are theoretical, magenta and the yellow are theoretical and
77:40 how they were done. So if wanna go ahead and do the same
77:44 in your area, you wanna develop theoretical model. And you have 1520
77:52 available to validate your theoretical model, P wave velocity, saturated density sheer
78:01 velocity grain matrix fluid effective models, matrix worth all these are computable by
78:10 we gave in this little section. we have theoretical models. All of
78:23 from one to the ninth is You compute you compute this, you
78:29 to the next step, just Then the next slide says, if
78:34 have unconsolidated model, here are the that you go through. You select
78:41 new process, you put it in and all these values are known from
78:49 beforehand. When you get done, gonna get a new P wave P
78:56 velocity for the new porosity. Then it's a consolidated digenetic again, a
79:05 , a new pro you get a P wave velocity to compute that.
79:21 here's the things that you'll notice. you ever hear the word inversion secretly
79:30 from one person to another? And tell me, yes, I'm doing
79:36 on my data because I'm interested in rock property. What are you gonna
79:41 ? I'm getting the acoustic impede. gonna get it by inversion. We
79:45 the prosthetic too by inversion. Oh are you? Deep water? Gulf
79:51 Mexico looking at Turbo lights or must exciting. How successful are they gonna
80:00 ? Let's take a look. In the deep water, they're gonna
80:07 in a deposition of model all the that they get are gonna be at
80:12 same depth. You look in this right in the middle of the channel
80:19 a San turbinate. San 32% you go up slight, little bit
80:26 top channel. There's a levy 26% , but they both have about the
80:33 velocity. Not much is changing. a significant difference in ferocity. Look
80:41 this little she is telling us right . Let's go back up to he
80:49 lost. It says I can go 3034 simos to about 23% ferocity.
81:02 my P wave velocity, it's only maybe 200 ft per 2nd, 300
81:09 per second, it's not changes it at all. However, if I
81:17 ahead and it's looking at the porosity this depth to that depth digenetic like
81:27 , then you're gonna get a significant in P wave velocity. It's telling
81:34 that in depositional type of settings don't to get good inversion and good ferocity
81:43 of velocity. It doesn't happen when looking at biogenetic porosity is sensitive to
82:10 impedes. When you're looking at a single row that a single acoustic
82:18 value is associated with the porosity range or minus 5% deposition, which is
82:28 , which controls, which is controlled effective pressure. And then ferocity is
82:36 secondary for control. Before applying digenetic depositional trends, you gotta validate a
82:44 somehow to see how essential they OK. No. How do I
83:02 this down for a second? OK. Can you see the
84:07 OK. This is an Excel program in the handouts that I gave.
84:15 called Excel rain moduli inversion. And have not covered the gray Margil lot
84:26 , but this is a, a time to look at the application of
84:31 digenetic models and the deposition I showed , you find a sand, it
84:43 be that shall send you have the and you have the all the other
84:53 at that one depth point. Then just fill out things like the poor
85:01 chill and sand properties. And right right beside and it's like gr green
85:09 , you have to say if it's or unconsolidated and then you put what
85:15 shell properties are and what your reservoir are. You can come back
85:22 this think of lithology. You can what mythology you have. Is it
85:29 shell deep water over here? You come to brine, you might be
85:34 at limestone for your reservoir. You done at the bottom here. And
85:43 gonna happen is the program based on you put in up here is it
85:50 generate a ferocity versus P wave velocity lot where I'm circling right now.
85:59 a list of here's your curiosity, wave shear wave in density predicted.
86:07 get back to the scrape a we in one point and all the rest
86:12 predicted it depends upon. Do you you have a consolidated or unconsoled type
86:19 a deposition? And that will allow to predict ferocity, which is the
86:25 to do it works fairly nicely and regimes. We'll see this again later
86:42 . This will point out it's OK. Let's take about a
86:51 10 minute break, about four I think we have a OK,
87:10 2.3 an isotropic media or did I something else this time? Uh Remember
87:27 famous geophysical saying, if you can't an equation for it, it doesn't
87:37 and it might sound funny. But you get done as well, you
87:42 doing a remote measurement and you really see it. So you're gonna have
87:48 take that measurement and somehow convert it an image or some other attribute.
87:56 here's one right here. It says size me trace S is a function
88:06 time and then at a given time , the second time, it's also
88:13 function of that. So once you a particular time, you gotta look
88:18 that time rate in here too. it's a function of your incident
88:25 the angle that you might go out the source, then it's a function
88:32 your asthma also, then we look here and say now here's a wavelet
88:40 that way was a function of I see another time right here
88:45 What does that mean? Oh What means is the way that changes shape
88:52 it gets deeper with time. So might sharp be a very sharp pulse
88:58 shells and its bronze out with And then this is the these are
89:06 reflection amplitudes, they vary as a of time incident angle in Asmus.
89:16 . But what about multiples in Oh, they are belong in the
89:24 not in the reflectivity. Now, will look at some equations,
89:32 transverse isotropy and horizontal, transverse isotropy a V. So amplitude versus offset
89:43 versus AMI or a va A amplitude angle and asthma or a B ABC
89:56 A oh I'm sorry, this got away. And then we'll look at
90:00 imaging techniques that are special to fracturing main people, both of them from
90:10 same company Amaco and this is the seventies coming into uh oh the early
90:23 and uh Leon Thompson, he is at the University of Houston here,
90:31 course, Geophysics department and Eloise she was the person who applied a
90:42 of the theory that Leon had And Leon is very good scientist theoretician
90:53 I've chatted with Leon many times and the young doesn't like what I tell
91:00 his most, his best contribution. I said, I said to
91:05 Leon's main contribution in his 1986 paper he made it readable for geophysicists.
91:14 didn't have to be studying this day and day out. He took all
91:18 research had been done on anisotropy and made two terms, three terms that
91:26 fractures and how you could find those in real seismic data. That's what
91:32 made it applicable. Now, there's Anders Ruger from car school of mines
91:40 a uh catalog of equations. I he's Russian and they're good at equations
91:54 can is soy in 1986 similar to film, Leon Thompson relates an isotropic
92:05 to measurements available to interpreters. Thus the mystic surrounding anisotropy micro. Here
92:19 some of the pro pro uh rocks have anisotropy shale is one of
92:29 And when you take a shall be bring your shell samples. Are you
92:36 geologist? You'll be caught outside in real world without your shell sample.
92:45 a geophysicist, I brought my shell . Here's my shell see layer one
92:51 two player three player four. is this an isotropic homogeneous material I'm
93:03 away. Done watch depends I'm sending same way horizontally, it doesn't
93:14 Oh The horizontal properties are stronger than vertical properties. It wouldn't surprise me
93:23 that the velocity going that way is because it's stiffer in that direction.
93:30 it's just what that is the uh beds and that, that's called an
93:39 anisotropic. No, what is Wow proper is the same everywhere you
93:50 that way, that way, that velocity is the same in any
93:54 That's an isotopic material. Well, homogeneous? What's homo genius then homogeneous
94:05 , is the same rock here as is the same rock over here might
94:10 NSR be in it, but it's same wrong not change. So let's
94:15 at isotropic layers and see what happens you look at them in different
94:24 For instance, here's a bed up the top and this is a nice
94:30 . I think Leon published this. gonna be traveling from here over to
94:35 , here to there, here to . And there's a fast velocity,
94:45 say at the upper layer and a velocity down below it looks like this
94:53 lower as a faster velocity. So travel time appear is greater than the
95:03 time down here. OK. So I put a a wave, if
95:11 have a way of coming in this , I should see that up at
95:16 top. The separation right up here time, right? In in in
95:24 is gonna be greater than down OK. I'll buy that. So
95:30 have a bunch of thin bits and what happens if I come and I
95:39 this. If I send a plane this way and these are different velocities
96:03 here. What is the wave gonna like on this side? Will it
96:09 like this is, will the wave like this? Will look like this
96:26 it travels through here. Hm. different philosophies. What will happen?
96:35 , obviously this individual didn't grow up Hogen, Christine Hogen. You remember
96:44 , little Dutch guy? And what he say? Every point on the
96:51 acts as a source for a new . And what it meant is when
97:00 generates, when he has a velocity as this as the boss, what
97:20 happen is as you're traveling through like , this point right here is it
97:31 go straight? It's going to generate all along like this as it propagates
97:42 this point likewise, it's gonna generate all along. So pretty soon you
97:53 what's happening, you're getting a flat even though you had all these sharp
98:03 right here. And so this has in there, but it comes on
98:12 flat wave flat plane can occur because the origen principle. So this media
98:28 here that happens to be fast, , fast, slow, it will
98:36 have wavefront looking like this. In words, if I put away from
98:45 over here and kick it to go , it's not gonna look like
98:50 It's gonna essentially be flat because of points reconstructing one of them.
98:59 what we would say then is your velocity, it's gonna be horizontal,
99:07 vertical as it turns out. So vertical, transverse isotropy. Mhm We
99:33 ready, talked about the bending of shell model and that was the vertical
99:44 isotropy. Leon likes to call this an isotropy because no matter which direction
99:55 giving you the same results. if I take my shield that turn
100:02 sideways, I now have fractures. are my fractures. If I shoot
100:13 this direction and these are all not, not different material fractures,
100:25 wave can't see the fractures because always to the fractures. I'm always hitting
100:35 material and those fractures are so small the that combination and healing of them
100:43 really affect the properties much. if I turn it this way and
100:50 source comes down, I'm gonna hit boundaries and those boundaries are gonna bend
100:57 they start bending, it's weaker in direction than it is in that
101:03 So going down, this looks like lower velocity, it's a lower velocity
101:11 that direction than it is in this . So you're gonna have a difference
101:19 how the amplitude reflects depending upon what you're at. And that's the horizontal
101:31 isotropy. Another thing about the horizontal of an anisotropy is here's an isotropic
101:48 . You better diagram, there you , an isotropic material and this plane
101:57 here is at an angle to this in my fractures, say going across
102:08 . So this is at an angle in there and now I go back
102:17 and what happens is this wave comes and as soon as it enters
102:24 it splits the wave into two different fronts. One is going to propagate
102:33 this orange plane with particle motions up down and one's gonna propagate horizontally in
102:43 particle motions or in the direction as blue has its sheer way splitting.
102:50 when you have she wa splitting, now take one share away, you
102:55 two. And I'm always amazed once than the other. I'm amazed when
103:05 go into processing, then you can what's called PS processing or SS meaning
103:18 can process the S wave. But time it hits a boundary, it
103:24 fast and slow, well, fast . Friends are always in the front
103:30 so they always, you can, kind of line up but that slow
103:35 all of a sudden there's a whole of them and they become all jumbled
103:41 . And I wonder how does it out? I just don't understand that
103:47 there's so many different, slow, philosophies. It kind of just smooths
103:52 and we only see the front wavefront . There's so many things in
103:59 I need to learn about some other that we see on an isotropic
104:14 If I clap my hands, air pretty, I should drop it.
104:23 Tessa, the Taa almost the same it reaches you too. You
104:34 Utah youtube is easier and it's the velocity. But when I have an
104:52 , what happens is at the same for a year, the wavefront can
105:02 closer for a given time. Then have, at the isotropic here,
105:08 have AAA balloon that's nice and And I know they don't like to
105:16 this. I said in this and wave from that's the same as a
105:22 ball that you sit on, you it and it has this type of
105:27 shape that means the angle, the that this wavefront will make to the
105:42 , that angle right there, it's than if it was is of
105:50 And we have examples of that that show toward the end of the course
105:56 it looks like if you do isotropic of measurements, it's oh that's 54
106:04 . But you will apply to no treat it as an isotropic at
106:09 becomes 40 degrees. Big difference. not as big as we think it
106:20 . Now here is the two parameters three. If you want to.
106:26 Leon introduced heavily used in mig death epsilon delta in Ada with all
106:42 the only one we really major accurately Ada. So let's see what they
106:50 mean. If you look at the velocity, it's related to the vertical
107:02 by one plus two epsilon. The move out velocity is related to the
107:16 velocity by one plus to delta. dealt this a positive number epsilon we
107:26 is a positive number. Ada is minus delta over one plus two
107:39 Now why? And gosh, names Leon give us a when we already
107:47 epsilon and delta, I mean, , it's, doesn't, it's not
107:52 at is, but the thing is can measure this. That's the thing
107:59 can measure. And so let's see we do it. OK? Don't
108:05 up here. C hey, close eyes, you're looking, I see
108:09 of you still looking. Oh, can't even follow simple instructions. Don't
108:14 up here. OK? You look when you do the normal move
108:22 what happens is the travel time to far offset. Race team is related
108:31 the vertical travel time. It's zero plus your offset distance divided by a
108:40 . And these last term square if you apply that equation, what
108:51 is on the CD P gather which is your near traces are flat and
109:01 they go into what's often called the stick. This is offset is equal
109:07 death. And on the far the, the event looks like it's
109:16 . Too much mover has been Now, originally, remember when he
109:22 these, this event really appears like . So oops appeared like this and
109:33 had to bring this and try to it up to about zero line
109:40 That's, that's the normal mover. again, when you shoot it,
109:48 events really go down like this. then with this, a correction,
109:54 ? Here you bring the data hoping it's flat from the near offset
110:03 this is to the very far. using this equation, it didn't work
110:13 the answer is right. And I give you a correction. So how
110:18 we do this? OK. The thing we do as we our data
110:27 I don't have this data, but mute my data. So all you
110:33 is data from zero offset to offset equal to depth. And that gives
110:41 what's called the short spread norma So I do a conventional velocity analysis
110:50 I only have the data to offset depth traces. Now I go back
111:01 say, OK, give me all traces. Now you already, you
111:07 then made a normal move out. you know those? Because so you
111:12 X is yes, you know what travel time T zero is you at
111:16 seconds. So I know my velocity , know my velocity trend, know
111:22 two seconds. You know my the only thing I don't know is
111:27 ada so you develop ADA as a of time, you make another velocity
111:35 but it's for eight of this time you know everything else that allows us
111:41 generate and a of function to put this equation. So that when this
111:50 , we can take, take these way out there and make them come
111:54 flat like this on the bottom. you use normal isotropic animo, don't
112:04 the extra term you get this and really want that to be flat in
112:11 way we get that flat again is adding this extra term right in here
112:19 searching for the A no, why we want to do that? Because
112:36 are the gas reservoirs. Anybody ever of Zula? Any Hair Hair ever
113:02 to the downtown theaters? M not theater down there. There's one hall
113:08 the Z the whole building right in front. Zilk A Zilka Mr Zoka
113:18 had business and United Kingdom, he the motherhood stores and he supplied the
113:30 , the beds, the cribs, for childbirth. And he had done
113:38 the whole United Kingdom, but he to make movies. So he sold
113:45 motherhood and came to the California to a movie producer director. Well,
113:53 didn't work out too good. So said son in law, you had
114:00 course you're now in charge of my . I wanna build, I
114:06 I wanna build an exploration company and in charge of it. You're gonna
114:10 me where to drill and all that of stuff. Hard drilling come to
114:14 it. No experience, not at . And they made a deal for
114:20 data. They said Fairfield lists up your data along the shelf.
114:28 it's massive amount 3d do for And what we'll do is if we
114:36 to drill. We will pay you much money before we drill and,
114:45 you can accept a percentage of the hydrocarbons that come out of that.
114:52 , your choice or for Seville, , why not data has been sitting
114:58 the shelf for a long time. I took it. So all this
115:01 data. Yeah, I was working this particular project right here and it
115:11 one block offshore, this goes back 1990 processing it. Meanwhile, a
115:25 by the name of Brian De Vault finishing his phd at the Colorado School
115:32 mines. And he writes me and , Fred, his dads, they're
115:38 Houston, his dad uh very well . He writes, we uh have
115:45 component data. We have these three three phones, horizontal, two horizontal
115:52 the vertical at each location. We the vibrator vibrating three directions vertical to
116:01 . That gives us nine recordings for jip though. And he says I'm
116:07 it, but I don't have enough part. Can I use your
116:11 I said, sure. So he down and he said, but I'd
116:16 to do some interpretation while I'm I said, you lucky guy.
116:21 got a project. I just get to the conference room. Big
116:26 There are 11 wells and I each I have the seismic sections. I
116:33 the CD P gathers in line Ross . I have all the aviom
116:37 all the synthetics interpret what we got he's done it for about a day
116:45 two and it's hard, really Well, logs don't wanna match
116:50 It's terrible. He comes up and , Fred, I said,
116:54 he says, we gotta go ahead process this data to make them look
117:00 this. Has anybody done that? , but we gotta do it.
117:05 I said, why? He says I see this on all the
117:10 13 wells, it has gas, big reservoirs and he says above
117:18 there's no amplitude just where the gas . We will make a seismic section
117:26 the only reflections on it are gonna those that have hydrocarbons. All the
117:32 reflections will go away. I come on, he says,
117:37 So we had a guy by the of John Sherwin and I said,
117:41 , we'll start the research to look on how to correct that. He
117:45 , oh no, no, Leon . They published it already said
117:51 And he said, yeah, I , why don't they use it?
117:55 says, well, nobody collected data that far of an offset. They
118:01 stopped at offset as they go to and they didn't get a depth.
118:07 we went over and we had data a company called or X. Here
118:14 is down your bro. And I , if you give us your seismic
118:21 , a 3d survey and this is I got it. We can't publish
118:27 . We don't own anything and we to show we can do 3D
118:32 So Oryx gave us the data. then when Brian found this out,
118:38 went to Oryx and I said, knows this and I showed him the
118:43 and I'll show you some se but unbelievable. I said, you just
118:48 to look at the bright spots and all proven wells. I said,
118:52 , you can't miss. I but I said as soon as somebody
118:58 sees this, they're gonna program, not that bad. Not that
119:03 And they're a hell of a lot people out there than we are,
119:07 they're gonna get it real quick. let's make a deal. I won't
119:14 for anybody else but you, but gotta give us enough data to keep
119:19 busy and uh here's what we're gonna and we're, he said, I
119:26 , this is big. I said good for you and we're gonna charge
119:29 3 to 4 times more than routine because it takes us that much time
119:36 and it's OK. That's what the company said. Next week I found
119:43 they took all the data we showed , went over to Western Geophysical,
119:47 over Geophysical. Who's the other another one? Uh oh the,
119:54 uh Norwegian one. I forget their and says, can you do
120:00 But only cheaper? Oh, you of a gun? So I went
120:05 to Zoko, I didn't know and son was down there and I
120:10 hey, in the, you're interested forming a deal. And Zoa,
120:18 son-in-law, the young kids said, , but don't tell anybody right now
120:22 you're doing. Just give me a or two a week. She called
120:26 next day and he says, don't anybody, don't tell anybody. He
120:31 here's the deal. If you don't this amount of money, we're talking
120:38 many millions of dollars within a we will go ahead and give you
120:44 difference. So you're guaranteed to make amount of money. Well, we
120:49 a lot of money. We processed and we were making profits. Our
120:58 , it was 75% of our People go for five and 6%.
121:06 getting 75. All the employees were bonuses equal to their annual salary or
121:15 . It was unreal Zilka in a and a half had so many wells
121:24 . It is embarrassing like Mobile. that was a classic, they farmed
121:31 a well. Mobile owned the property Zuko would like to drill a well
121:38 , but it was fine, you , here's the deal and it's fine
121:41 they drilled the well, it was booming success. It was in geo
121:47 and it just came out. All other companies went, took the same
121:52 data and they couldn't process it. couldn't get it to match.
121:58 the one thing was when you buy , they sold a different way.
122:09 gave everybody else CD P gathers that out to 20,000 ft and we took
122:18 raw field data that had access to ft and we were processing data out
122:27 30,000 every time. And it turned , where was all these signatures
122:36 As the death also twice the Zilka in a year and a half
122:43 himself for $1.75 billion and they started with nothing. Zilka was asked all
122:51 time, how can you be so ? He says, well, we
122:55 the technology and I said, you , you can take credit for
122:59 You just keep paying me. So was a story where the oil companies
123:06 thought they were getting by asking other to do it cheaper. Unfortunately,
123:20 lot of the people that were with company doesn't exist anymore think they were
123:26 more brilliant and trying to show other . Oh, I'm brighter than
123:30 I can make a better deal and making a better deal. It's
123:37 OK. That's why I like this right there. Here is an example
123:45 modeling a a little model case and shows you the prom parameters, the
123:58 and the delta for this little three model. And here's the equation right
124:10 and it shows the wet case from to 50 degrees. It shows how
124:18 amplitude dies and then wet case just close to zero. Well, the
124:27 has a definitely different signature, higher on the far traces and of
124:32 immediately, well, I we do all the time. Well,
124:37 the epsilon and the delta are hard measure. You don't get them
124:43 Well, lower curves, you don't horizontal velocity off of a wall
124:49 you get vertical velocity. And so though we had the equations, it's
124:56 extremely difficult to apply them in a resolution. So what we found that
125:11 we can measure that we could use for imaging when we do no mova
125:18 we do migration A enters into the , this is this is prestack time
125:26 seismic estimate of the an isotopic parameters too coarse for Avio modeling. So
125:36 was necessary and what was happening? need more lab measurements of anisotropic
125:45 And that has a story also in 19 seventies eighties, Amao Bill.
125:57 of the I think the best research I run they got very involved in
126:06 aar to be. And when they a new well, they would take
126:11 shipping container which contain all the instruments measure anisotropy and then load it onto
126:21 plane and fly it to where the well was. So they had several
126:26 those containers and they were getting measurements the world trying to develop a
126:33 Why I can see they are hoping come across another Archie equation. Archie's
126:41 for saturation. Thousands of models went when they start seeing a relationship,
126:48 then went to the theory. You think they got a theory first.
126:52 make measurements. Then they try to that theory. And Liam was part
126:57 the group that were dynamical at the and BP bought AM and what did
127:05 Do? They shut the light They let all those employees go.
127:11 , I don't know what happened to the samples that they had.
127:16 BP and BP basically said, we don't need it. We can
127:21 the literature just as well as somebody . OK. Oh oh I need
127:32 water. Oh Lakes work. Thank . Be OK. Why did you
127:45 it sit for so long? Let's this. The beer garden closes at
127:59 tonight, by the way. Oh at home. We're not going to
128:03 you where the beer garden is. , I'm just teasing. We'll tell
128:09 in Dallas HT I equations. I'm not gonna go ahead and show
128:19 the derivations. Many I could show . I'm gonna tell you that the
128:24 are there and they're from this guy , Ruger and the SCG, he
128:37 a monogram containing all the equations and can get an electronic version of it
128:46 that's how I basically say do it he, he does a very nice
128:52 of what the equations are. And are rather lengthy. For instance,
129:05 you're doing it in as a vo versus offset, you usually break up
129:12 shooting plane down in here, maybe six different vectors, 123456 different vectors
129:21 do the processing in each vector. one way of doing it now,
129:28 doing so you also then begin to at when you do identify the
129:35 How do you name them? if you have fractures, as you
129:40 this direction, those planes that are are called the is isotropy plane,
129:48 that go perpendicular or the uh symmetry . Then you have a vector
129:57 this is about Ruger's notation. That's incident angle and P which is the
130:03 angle. And now we start getting the reflection coefficient. This is the
130:15 term isotropic equation. Sh is three for angles less greater than 30
130:24 This is for angles less than 30 B and C are defined beneath
130:34 Then he said what if you have HT I medium, fractured medium over
130:41 fracture medium and they're not going in same direction fractures are different. He
130:47 you an equation for that. And what if you're shooting in the isotropy
130:57 symmetry plane? It gives an equation that. He also shows you an
131:05 where you can use to say what you're shooting perpendicular fractures or parallel the
131:11 . And he shows you how the will vary as a function of
131:20 All of them are nice and you go ahead plug them into Excel.
131:25 wanna show you some examples. Fraction , imaging anybody bend at the
131:33 See the water tank down science and one basement. They still have
131:43 No. Hm. Yes. Nobody's using it. So what?
132:01 , I, no water in the or just not in the tank?
132:08 . Well, this was done in tank a long time ago. These
132:19 piece of plexiglass right here in the and in the middle or microscope
132:29 the ki the kind you put a of spit on and see what bugs
132:33 flow in there and I don't know of them and then there's a screw
132:42 both ends of here. So once get them kind of lined up,
132:48 can tighten those screws and close the between those microscope. And you can
132:56 these together two ways, you can it on a dry desk. So
133:01 you clamp these shots, they're clamp water can hardly get in it.
133:07 can't, you now have gas in fractures or you can go ahead,
133:14 it in water and that water soaked , then closed the clamps. Now
133:19 have water in the fractures. So two different cases. Yeah, this
133:28 a depth migration where it's an in perpendicular to the fracture orientation. And
133:36 are the fractures. And this is way of doing it. You can
133:42 ahead and do a fraction detection, . And again, the N line
133:51 is perpendicular of the fractures. And notice look at these right here compared
133:59 the fracture detection and basically what the detection is, it says I don't
134:08 any normal incidence reflections, I only scattered energy. And so it doesn't
134:16 anything that's gonna be normal to the . Now, here is the death
134:23 slice and you can see the fractures horizontally here and these blue or acquisition
134:41 . And if you ever do that is the most frustrating is to
134:47 the acquisition artifacts out of the There's always something that you don't
134:56 When you're using a little crystal, goes pop and you're gonna use that
135:02 a sound source. You gotta Well, do you know what
135:07 That crystal would pop? But that hinge up at the top that you
135:13 to hold it in the water? getting big energy off of that.
135:17 giving me reflections. So you gotta out how you keep it in the
135:22 . Uh oh I got a really offset. Uh How deep is the
135:29 are you gonna be? Not be to put it deep enough that you
135:32 get reflections off the sea level, like that another uh fracture coda.
135:48 fractured coda. If you shoot all the fractures, that's a terrible
135:53 to do it. Whenever you have , you just have noise everywhere perpendicular
136:01 the fractures. This is Jupi law the noise shoot perpendicular. Look at
136:09 you can see horizontally as the Previously, you can't, you got
136:19 . Now there is another way of very far offset to delineate fractures.
136:31 is anybody process se me dude. . When you process seismic data and
136:48 look at how close for the source the receiver, if you're having sourced
136:55 energy to a boundary, then back at the receiver. If the distance
137:01 the source and receiver is equal to depth, that's OK. But when
137:08 source and receiver start getting farther then the death, then when you
137:16 to make that event flat, your are stretched and when they're stretched,
137:24 a very low frequency. So we a technique where you don't stretch
137:32 Here's conventional processing. And when you to the very far offset, you
137:40 have large stretch versus seismic wide angle . When you get to the far
137:47 , look at the wavelength, it's the same from the near to the
137:54 offset. There's no stretch and the content remains because we migrated this but
138:09 no normal will in a sense. when you migrate, you don't apply
138:15 robots. And this will show you is real seismic data. The play
138:31 right underneath these in hydrate beds, sands and you'll notice the fault and
138:40 the, basically the zone of interest looking at and I'm going to flatten
138:51 state here in a second. So the fault and I have books to
139:02 false sitting in there and I flatten data on top of these in
139:12 Just take that, make it flat that's what you get up at the
139:20 here. This is the 0 to degree angle stack. It's migrated.
139:26 is the 30 to 50 degree angle . It's migrated. Look at the
139:31 frequency in here, very hard to any mythology or poor flu information.
139:40 when you go ahead and do this normal, move up, look at
139:47 far offset. Now look at the that you can see right there that
139:55 can't see before. So it's a fracture detection technique and you can get
139:59 the far offsets if you have fractures you compare it to your thought
140:11 So here is a water tank example you're shooting across a solid piece of
140:22 . So you got a really thick of plexiglass and this is the fracture
140:31 that red line that is the normal corrected reflection. This is a head
140:38 , this is a refraction below. the same thing except now we have
140:48 and we're shooting perpendicular to it. at the difference. Look at that
140:55 , it's gone. Look at the here, the reflection you don't have
141:00 here. So if you look at versus in my, that's a good
141:08 , the finding where the fractures are . And of course, looking for
141:17 attributes, which we'll see later. . What time do we go
141:23 Six or seven? I forget. 551 five. You're kidding?
141:38 Any que que questions and comments, what are not set? We still
141:49 for this kind of more detect uh , detecting that very. The questions
141:58 been asked if you had metamorphic rock volcanic rock and it's all scrambled
142:09 Can you use the same technique? never ran a real model on
142:17 Um I'm going to guess that it's be difficult because of possible localized variations
142:32 velocity that break up your wavefront. that's the very thing you're trying to
142:41 together to give it image. But again, I could be 100% wrong
142:49 you can get a very nice uh . It's one thing here have to
142:54 and see it. It, I tell myself when somebody asked me to
143:01 a theoretical model, I tell my , I know what the results
143:05 I'm just doing this for you. then when I get done running,
143:08 said, oh my gosh, I all about that. Yeah, you
143:13 something. Yes. Good question Anything else? OK. If nothing
143:28 we'll see you folks. Right. early
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