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GEOL6363 Carbonate Sedimentalogy - Day5 09-10-2021-Part1
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00:04 Okay. According to this diagram, not muted. Right? Mhm.
00:12 am not muted. So we'll go . I'll go ahead and start recording
00:20 has already recording Mhm Yeah. So we finished up last saturday talking
00:48 de positional sequences in cyclist city. . And they're going to be some
00:53 on the exam about that because that's important for you to understand how these
00:58 of carbonate sediment are put together. . The effort Shoaling sequence concept that
01:03 talked about the use of the cycle for correlation at times photography. You'll
01:10 the application of all of that to uh delineation, Orzo Nation.
01:17 next friday. But I want to on that relationship by talking briefly about
01:23 responsive carbonates and uh and seismic And Sure. Have you, those
01:32 you been around? Have you gotten exposure to logging techniques? So you're
01:38 with the basic uses of the logs Okay. Maybe not less. Advanced
01:46 . Certainly a lot. Okay. then seismic. Have you had any
01:52 interpretation? Okay. So I'm not I'm not gonna go into a lot
01:57 detail about this? Mainly I'm gonna out from the standpoint of first of
02:02 , how forgiven de positional setting. can we use some of these
02:06 Sweets to break out these depositions Right. Because everybody, most
02:12 their primary databases are seismic and well . Right. And companies try not
02:19 core try not to collect samples if can avoid it. Alright. So
02:25 forces people to interpret relationships from seismic or to interpret relationships from the law
02:32 . And I want to show you that's a little bit harder and
02:35 that there's some pitfalls to using these sweets to try to do that.
02:41 , now, I mean Angela works a company. So you know what
02:46 talking about and uh you know, going to be forced to do this
02:53 , but you need to least know the limitations are. All right.
02:57 be honest with people when you make interpretation that there are some potential limitations
03:03 to either understanding what the deposition all was from law response or what was
03:09 were the packages put together in terms their stacking relationships, thicknesses and stuff
03:15 that. Okay, so, we'll with this first slide here. There
03:20 uh some qualitative aspects with respect to and carbonate sequences that we can that
03:27 can talk about and try to Sometimes the logs can be useful for
03:32 or correlating these time equivalent de positional or for recognizing and even delineating deposition
03:39 faces. But in the world of , how well you do this depends
03:44 what kind of rock data you have calibrate against the log response. You
03:49 to calibrate. All right. And ideal situation is to have at least
03:52 poor data. Right. Core is the best because you see color sedimentary
03:58 . Contact relationships. Right to some the bigger fossil fragments and things like
04:04 that make it a lot easier to the de positional setting. Then say
04:09 little bits and pieces of the well that uh every company collects may not
04:15 at, but they collect that data the well site. All right.
04:19 then the other thing that can bugger these relationships is the degree of die
04:24 . I think you've got an appreciation our discussion last weekend that the dye
04:31 can sometimes mask the deposition all Right. And organization in particular.
04:36 even limestone dia genesis, you can a high degree of re crystallization that
04:42 mass some of the grains or the matrix. And then the third point
04:47 , the quality of the log? has to do with the age of
04:49 locks. Right. And these older , people deal mainly with the old
04:55 resisted the logs and you can do with that sometimes. But that's not
05:01 good a log sweet as the more logs. Right? The more modern
05:04 logs, the p logs, the logs and things like that.
05:10 and then when you're trying to correlate particular from well to well, which
05:14 what most people try to do They don't today, they don't usually
05:19 do that on paper, they do with a computer. But what are
05:24 trying, what are people using? using for some sort of pick on
05:27 logs, right, some wrong some response that seems to carry regionally.
05:32 people will try to correlate from one to the other to set up a
05:37 graphic framework. But the danger there you need to know what that's responding
05:42 right from a deposition all standpoint or it's caused by di genesis which is
05:48 misleading. Right. And so part part of the issue for correlation is
05:53 need to have at least a feel your gross de positional setting.
05:58 how are you going to get Well, either you're in a mature
06:01 and you sort of know where you're your wells or if you're in a
06:06 mature basin then you hope seismic data guiding you a little bit right.
06:11 know that there's a platform to base transition and you know maybe where you
06:16 along that that can guide you when trying to correlate. And we had
06:20 discussion a little bit last saturday. . Remember the two end member models
06:27 how the cyclist city varied depending on you look along the deposition all
06:32 Okay. Okay. So do illustrate . Let's just do a little exercise
06:39 . We've got these five wells that out to be completely cord but this
06:44 the log response and this is from Devonian in Western Canada. And you
06:50 see the thickness here and you can one well produced and the others didn't
06:56 everything is dated on top of of the fort vermilion and hydrate,
07:01 is a uh, probably a title evaporate. All right. So that's
07:06 good bottom datum. You always want date him on. You always want
07:10 date him below your sequence of If you can do that usually most
07:15 time you can't do that. Because most companies won't drill through their
07:20 . But ideally you want that bottom data because if there's any later tectonic
07:27 by faulting, that's going to show right where reef is sticking up above
07:32 title flat when you correlate from one to the other, right? There
07:36 to be some offset along a right? Because you're not going to
07:41 deposition the higher than a tidal Going to be the other way
07:44 Okay. Yeah. And so what the two logs here on the left
07:50 each of these logs is a gamma on the right. Is a porosity
07:55 . Okay. Destiny log. And you ask most people to correlate,
08:02 would they hang their correlation on from ? Will, what would you,
08:06 would you hang your correlation on? people would, would correlate from gamma
08:13 gamma to gamma to gamma. And what would you do hear you probably
08:17 it in here somewhere and here the is not quite as sharp.
08:22 Yeah. And so for carbonate what are you assuming? What are
08:29 assuming this is if there's no gamma , what causes gamma ray response by
08:35 way, radio activity. Right. what does that tie back to
08:44 Aly, neither ties back to a delicious or carbonaceous carbonate rock, fine
08:54 carbonate rock. Right. Or the dolomite. Right? So sometimes dolomite
09:02 nobody really understands why, but sometimes will preferentially incorporate uranium and give you
09:10 response. Okay, And that may may not have anything to do with
09:14 deposition. All setting. Okay, what are we doing? We're assuming
09:23 this is what All shallow water Right, shallow water, higher energy
09:28 more unlikely to incorporate our delicious or material. Right? We're likely to
09:35 clean on the gamma. Right? and a carbonate seminar people would probably
09:41 this interpretation right? You would tie gamma from well to well to
09:46 basically, what are you working out ? You're working out a platform to
09:50 in transition. The more ratty gamma log over here would reflect an increase
09:56 water depth. As you go out to deeper water. You can see
10:00 that was a strategy off of which was drilled, right? They drilled
10:04 the high energy platform margin. That's northern Bahamas model we talked about last
10:11 . Okay, now if you had the rock data, this would be
10:16 proper interpretation. Alright, it's actually platform systems. Right? The main
10:24 is off to the southwest. And know, they drilled up on
10:28 They didn't find anything right here. then what they actually drilled out here
10:33 an offshore isolated carbonate platform surrounded by water deeper to the northeast. But
10:41 in between these two little embankment and payment was filled in with what?
10:47 slope. This is that displaced shallow carbonate sand. Right. That we
10:51 about. And where is there more it? There's more of it off
10:56 side. Which turns out to be want to guess when word early
11:04 That's the leeward side. Okay. respect to the trade winds.
11:07 And you're in the right energetic train belt system. Alright, yeah.
11:13 then then it fills in with some basil carbonate. So, here's the
11:18 lesson to be learned. Right? just because you have a cleaner response
11:22 gamma ray doesn't mean it's all shallow . Right. And it also means
11:28 basin will carbonates, which is what green represents. Can also read clean
11:32 the gamma. There's this concept that deepwater carbonates read ratty or have a
11:39 on the gammon. That's not If you want a good example of
11:43 . That's the Austin chalk here in . All right. Most of the
11:46 chalk reads pretty clean on the gamma you incorporate some are delicious material or
11:52 volcanic ash or something like that. right. Mm hmm. You see
11:57 it changes the whole story here. you look at the ROC data and
12:00 , it increases your potential here for play development. So where would you
12:05 they drilled out here? They drilled that people water force of stuff.
12:10 didn't find anything here because there's no . Right? There's no way to
12:14 the carbonate the oil here. Where you want to go? You want
12:17 go up against that platform and look entrapment right there. So that's
12:22 that's a prospect right there. And know, again, they drilled up
12:26 the platform here. There's still potential drill out here on the margin as
12:30 would be to drill on this margin here. So that's the whole point
12:35 that, you know, the ideal is always to try to integrate what
12:39 of whatever rock data you have with log response. Right? So cora
12:44 ideal. The most companies are not to core every well because they're too
12:48 . Right? Cost money for the time. So, what's the next
12:53 thing? The next best thing is or percussion sidewall cores, right?
12:59 at least they're coming roughly from the graphic depth, right there can be
13:06 on that tool to so you can off a little bit. But that's
13:10 than cuttings. Right? Because cuttings collected anywhere from five ft to 60
13:16 . And from my experience, I've lots of cuttings data for projects.
13:22 60 ft or even 30 ft is worthless. All right. Because it's
13:26 jumbled up. Right. It's all up Over that 30 or 60 ft
13:31 . But if you collected five ft 10 ft or even 20-foot intervals and
13:35 carefully work that stuff from not the up from the top down. you
13:40 see what is contamination and you can of figure out what mythology is corresponding
13:45 to what depth. And then you relate it back to the law
13:49 Okay, So that's what you always to try to do. And
13:55 that's the ideal situation, which a of times frustratingly doesn't come into play
14:01 an oil company. All right. ferocity. It was it was the
14:12 for the for the yellow. it's a seal. So the stuff
14:16 sealed with the stuff would likely be likely sealed up against this or depends
14:22 the structural tilting too. Right. maybe over here there's some entrapment up
14:27 that margin. Sure. Yeah. is it's also force, well,
14:34 of that report would be porous and . That's where you'd want to be
14:39 at what faces has the reservoir Right? Or if there's a delay
14:43 effect tied to a faces are a within the cyclist city. Right?
14:49 you're gonna you expect in a shallow system as we talked about last week
14:52 there to be probably multiple stacks Right. And so it's a question
14:57 what part of each cycle has the quality. Okay. So, what
15:03 lot of companies do. We'll have discussion uh tomorrow afternoon. Probably.
15:09 a lot of companies do historically, they when they say they identify an
15:15 structure like this where they going to , they're going to drill into the
15:20 . Right. Then I got drilled it. They're gonna drill into the
15:23 . And they're going to make this . That structure is filled with spill
15:27 . Right? And if you just into the upper part here, you
15:31 suck it all out. Right. there's a lot of bypassed oil and
15:35 in the rock record because of Because companies didn't realize their vertical permeability
15:41 that separate these deposition all cycles. there can be virgin oil or gas
15:46 those underlying cycles. All right. I'm going to take you through a
15:50 study like that tomorrow afternoon. All . So, that's the other the
15:56 assumption. All right. So, is this is where we're headed is
15:59 discussion about play relationships and how that's by age and setting and then starting
16:08 afternoon, I'll take you through different for creating the ferocity. Alright.
16:15 . Deserve concern. The exterior This charge these steps variability process.
16:26 No. Sure. That's always a . Right. So, maybe
16:30 So, imagine that fixing the child looks good. There's nothing in
16:37 Could that be? Because there was No. Yes, that we get
16:42 . Yeah, that's a risk. always something you risk. Right?
16:49 talked we talked about this I think little bit about the Well, we'll
16:53 about this for some of the play , right? Where's your source
16:58 And how far do you have to that generating hydrocarbon from the source to
17:04 trap? Right. Is there a distance migration or pathways issues where you
17:10 to go through some impermeable faces? . Be secure? Yeah,
17:17 Is that a higher risk for apartment place? So surprising. I don't
17:23 why. I mean, I think think carbonates probably fracture a lot
17:29 Right? On a micro scale. , when you start generating that
17:33 I don't I think it's probably easier sort of micro crack it out of
17:37 source rock and start moving it. huh. This is a question for
17:44 geochemist and you're in your third right. Dr basada should be able
17:49 answer that question. I would hope least address it to some degree.
17:57 , All right. All right. , this is the methodology. And
18:03 , you always start with the rock . Whatever rock day do you have
18:06 trying to break out the face these and then see how things are stacked
18:11 these depositions cycles. And then look reservoir quality. Does it tie back
18:16 a deposition all faces within each of cycles or is a die genetic in
18:22 , but it's still types back to in the cycle. Right? And
18:26 you just whatever rock data you've broken . You make sure you adjust it
18:31 any shifting. Right? Remember log tools stretch. Right? So sometimes
18:37 off by a couple of feet. they're off by 10 or 12
18:41 Um And if you're if you're if you're using core data, the
18:46 you figure that is you run a gamma over the core and then compare
18:51 to their gamma ray log for your . And then that's the best way
18:55 see how things have shifted. And you start correlating right? You're trying
18:59 correlate deposition environments deposition all faces. really what you're trying to do.
19:05 not trying to correlate mythology. You're to think in terms of the 2M
19:09 models that we talked about last Okay. And once you do that
19:15 , well, that has good rock . Then the goal is to try
19:18 extrapolate that to the next well into next well. And I've seen people
19:23 into the world of statistics, you , digital digitizing the data and doing
19:28 plots of log parameters right? That been ground truth with some of the
19:33 with rock data and then trying to that. And sometimes that works pretty
19:38 until you do what you change Right? Or you change your
19:43 That's going to happen sooner or Right. Should correlate laterally? So
19:48 that's the challenge. All right. . So let me let me share
19:52 you some general relationships here with respect well, logs and breaking out these
19:58 deposition. All cycles. Sometimes the gamma ray can mark the cycle
20:04 especially the the more major cycle Remember the difference between minor and major
20:11 cycle when we went from really shallow to really deep water setting. Minor
20:16 contact. When we went from, the title flat to a shallow
20:20 That's deep over shallow, but not major deepening. Alright. And then
20:25 the proxy logs can track these opportunity characters you've seen as we shallow,
20:30 , shallow. It means we're getting to where sea level was. And
20:34 that increases your chances of higher energy and better primary porosity and permeability.
20:41 doesn't mean every the top of every patrolling sequences. They has good
20:47 Because what could the top of an only sequence B It could be a
20:52 title flat, Right, evaporating That that pro grade it out.
20:56 not going to have any reservoir So, so the point is you're
21:01 going to look for better reservoir quality the base of a deposition. I'll
21:05 you can look toward the top. , again, the caveats here are
21:10 you have to really understand your fizzy setting, which at this scale
21:15 What's your bottom topography? What model guiding your interpretation of the rock
21:22 You've got you've got a ground truth rock data with the logs and then
21:26 the back of your head, you've got to be concerned about that digested
21:29 print. Okay, so let me with you some relationships here. These
21:35 were given to me by my friends colleagues, Jacqui and frank Stokes.
21:40 both live in Calgary, they're both now. But but this was their
21:47 of using these different log suites in world of Devonian mississippian carbonates, which
21:52 the major carbonate sequences that are oil gas productive in Western Canada. All
21:58 . But the examples I show you not just from Western Canada. I'll
22:01 examples from other parts of the world from younger sequences. Okay, so
22:08 were thinking in terms of these overall general fizz a graphic settings.
22:14 the first one would be an overall water platform or reef related carbonate
22:20 Alright, so in that kind of , which logs help you break out
22:26 depositions packages? Well, sometimes the ideologues but generally not. Alright,
22:35 limited use would have better better expression sp logs picking up these changes in
22:43 . Right? Because that's what the is really responding to. As changes
22:47 permeability from one faces to another. sometimes that reflects a change in in
22:53 positional texture. All right. And of course the process logs. All
22:58 . So it's really the sp longer if you're working older data or it's
23:03 more modern proxy logs to help you out these packages. Gamma ray is
23:08 just saw from our little cartoon, . Gamma rays usually doesn't show good
23:13 . Overall shallow water carbonate succession, picks up that transition from shallow water
23:18 much deeper water faces. Okay, first example here is from the cretaceous
23:25 south texas. This is a Part an expiration target that was drilled back
23:30 the mid 1960s. Uh, you see the data here. The core
23:38 is uh let me go back. can see when this is originally published
23:46 in the 70s. This is how used to characterize mythology. Right.
23:51 you see the problem here, we've this discussion. Right. What is
23:55 faces? What is the environment of ? Well, for bounce stone,
24:00 would you say brief. Right, what about a grain stone? Is
24:07 a beach grain stone? Is that subtitle with sand? Body grain
24:12 Is that reef related grain stone? see the problem the same thing with
24:17 Pakistan or Pakistan. What's your All setting? This is not the
24:22 you want to do it anymore. , so it's just Oh, you
24:29 want to remember how we define the faces a rock? The reflects the
24:35 deposition. Right. So you don't to think in terms of pack stone
24:40 wacky stone. You want to think terms of title flat, right?
24:44 the faces are based on lime stones faces because it keys you into a
24:48 positional setting. Okay? But here see the sp curb was only then
24:55 had a resistive itty which didn't really much, but they could see the
24:59 curve shows some variation here. And core description. You can see repetition
25:04 some of the grain stones and you see the obviously the reef here and
25:09 the black shale is a real That's what terminate your overall shallow water
25:15 system. And you can see how and perm ties back to the faith
25:19 the mythology. But this is the you really want to do it.
25:23 right. So, this is part a core exercise that I use in
25:27 training. So I've gone back and reinterpreted all the pathologies and put it
25:33 a deposition. All faces contact So, you can see the reef
25:39 is the red. But now look the the yellow up here, that's
25:43 flat debris, Right? That's the the debris generated by the major storm
25:48 . And then you can see that grain stones down here in blue are
25:54 shoal surrounded by the stabilized flank. , little shoaling cycles that go from
26:00 water too shallow, repeat over and again. So each one of those
26:04 from the blue to green, blue green is a cycle break that we
26:08 about before. A cycle contact. ? And you can see how there's
26:12 response on the sp but it doesn't all the way to the shale
26:16 So that's not due to shale That's due to a permeability change,
26:21 a change in reservoir quality. All , so the light blue intervals would
26:27 excellent reservoir quality. They have anywhere 15 to 25% ferocity. Some of
26:33 samples up to hundreds of mila darcy's permeability. Now here didn't know none
26:39 this produced. Okay. But the , the small scale cycles are being
26:45 by this. And then where is major cycle contact? Right here?
26:49 the reef gets drowned out by a shale? You see how the sp
26:54 all the way over to the shale . So, you know, that's
26:56 shell response. All right. And look at the, look at the
27:00 of the reef here, it's relatively . There's no porosity here, for
27:06 we've talked about before. Right. be marines imitation, or it could
27:10 that that was a deep deeper part the reef that as a reef of
27:16 thicknesses. Right. The lower part the reef was still bathed by marine
27:20 . It was not high energy So, there's still organisms living there
27:24 mud and silt and never got washed . And then I'd also set up
27:30 pressure solution compared to the upper part the reef. It has great reservoir
27:34 . And then of course the debris above it have great. So you
27:38 see how that all reads clean on sp but then look at this deflection
27:43 here. That's not a cycle That's just uh that's just a mormon
27:48 Laguna carbonate that punctuates that degrees. . So in here, so you
27:54 to be a little careful right? assume every deflection is the cycle
27:59 That's why you gotta look at the right? It just comes down to
28:01 in the world of carbonates. okay. Yes, that's it.
28:08 huh. You say no brief court the institute part of the reef.
28:16 our two sub environments, brief core debris sheets on either side.
28:23 So what would so because it's it's not all frame stone. In
28:30 , there's uh there are only a , maybe A few intervals within
28:37 I forget how thick that is. about what? 5th? 40
28:41 30 40 ft. There may be a couple of five ft intervals where
28:44 see stuff that's in growth position. rest of its rebel. Okay,
28:50 bound together. Yeah, well, showed you that diagram last week.
28:57 that remember the Corey wall with the of frame stone versus sedimentary debris and
29:03 varied Anywhere from 60% frame stone 25% frame stone, but in a
29:11 , a bull reef body. So that's the variability you get on
29:18 sea floor. Right? If you to snorkel over reef today, you
29:22 just see wall the wall stuff and position. You see stands of stuff
29:27 growth position here with a little another growth over here. What would
29:31 filling that depression, all the Right. And then what were
29:37 Just because you see growth at the ? Doesn't mean the whole thing is
29:40 growth position. Actually, a lot the last spaces of instantly reef grew
29:45 rebel. It's been broken up by storm. So that's the challenge.
29:54 . And then a couple examples from Jurassic in Saudi Arabia. The Arab
29:57 . We'll talk about the arab D later Arab D is uh yeah.
30:07 D. Is the main producer for Saudi Arabian Jurassic. Right? All
30:13 big reservoirs produced out of the arab . I think I mentioned How big
30:17 structure is 1500ft enclosure goes from basically driving from Austin to Houston.
30:25 so here sp log on the a sonic proxy log on the right
30:31 . This is the way you don't to describe faces. Right? They're
30:35 these are just mythology descriptors basically. you can put some of this into
30:40 environmental context. The skeletal sands or energy grain stones. All right.
30:47 this classic keratosis, that's the type coral is a deeper water coral,
30:53 a high energy reef. Alright. then you can see they plotted the
30:59 types anhydride ola stone and limestone over , essentially what you have in the
31:07 is a upward showing sequence at the that goes from here to hear.
31:13 that's a major cycle contact because you're from grain stone into a muddy carbonate
31:18 a deep, deep subtitle carbonate. right. So deep over shallow.
31:24 was our definition of a major cycle . And then what do you
31:28 You go back and great up you go up right, sorry, go
31:37 up into a high energy grain Okay, with good porosity. And
31:43 it's capped by these red beds and . That's the stuff that piggyback our
31:48 did over that Greenstone. That's basically socket deposits we talked about in the
31:55 . All right, so look at process log you see this increase in
31:59 toward the top of the cycle. a dramatic decrease of the cycle contact
32:04 you're going back into deeper water and an overall increase in ferocity toward but
32:09 at the top of the cycle because captain faces are these types impermeable red
32:17 and evaporates. That's the top Right now, you see sp really
32:26 track that right? Like we saw we saw the sp than the previous
32:32 sort of kick a little bit of contact right here. And you don't
32:36 see that. The sp effect, see, right here is the hydrocarbon
32:42 . We've got some dead oil in porosity, so, it creates low
32:47 . And that's why that kicks back here. So, the sp really
32:51 track the cyclist. It's the paparazzi . You see the prostate increasing dramatic
32:56 of the cycle contact, gradual increase . Okay, so sometimes it's the
33:02 log that helps you break out these and you can see this scale
33:07 That's what 100 ft, right? a typical scale in the Arab
33:14 There are about 30 m thick cycles repeat over and over again. All
33:21 . And then just to show you copy out here, let me go
33:26 . You see the dolomite here. dolomite really doesn't play much of a
33:30 here. Sometimes the dolomite just replaces grain fabric and doesn't create ferocity,
33:36 we? Didn't we see some examples that earlier. All right.
33:41 here, demonization doesn't play a role the process of evolution. But if
33:46 look at this example, we've got the same succession of faces. The
33:51 to upper chilling sequences here. We've our long sweet to a gamma and
33:57 porosity blog. The cycle contact is here. All right. So,
34:04 stone in this case the Sturm atop coral is a deeper subtitle face is
34:09 a reef. And look at the log. It's all over the
34:14 Okay. There's no consistent pattern. gamma doesn't respond to anything really here
34:19 there's no incorporation of articulations or carbonaceous in this overall shell and rain
34:28 Okay, So here's the example where dye genesis sort of buggers up the
34:34 from a deposition. All cyclists t . Alright. And some of the
34:39 reservoir quality is due to demonization. of the better result qualities due to
34:45 fact that it's still limestone. That's the caveat. You've always got
34:49 be concerned about that over print of die genesis on the log response.
34:54 right. Yeah. Mhm. that's right. If you're working,
35:12 you if you know it's a carbonate , you want to try to run
35:15 those long sweets to really try to pinned down the relationships from a deposition
35:22 faces or cyclist city standpoint, of , also from a process, a
35:27 quality standpoint. Okay, then this is from the Devonian Western Canada.
35:36 is part of a broad carbonate platform in Alberta and you can see the
35:43 have been broken out here for These are just a series of stacked
35:49 . We're chilling cycles of sedimentation and ray log was run here and
35:56 you see this camera is not picking on those cycle contacts because there's no
36:02 not a deep major deepening. Where you could incorporate our delicious or
36:07 material, Right. No organic material would bind uranium and no, no
36:14 no uh, shale material that could an uranium. So you expect the
36:20 to read clean. It's only at major deepening. All right. Did
36:24 get a response And it's this kind relationship here where the lower cycles all
36:29 clean. But then you see a by a good yammer response. This
36:34 what we're going to end up calling composite cycle here in just a
36:37 Okay. And composite cycles are bound good camera response on both the bottom
36:44 top. And it's those responses that all the way across the platform or
36:49 the way across the basin. Those what you used to set up your
36:54 time strategic graffiti. All right. general is setting basal carbonates and evaporates
37:01 basal setting. Deepwater setting. We've about how you can get deep water
37:09 . Right? And we've talked about based on carbonate deposition. Now,
37:15 guess the question is you would you you ask the question, why do
37:19 Canadians even care about these deepwater Well, they care about them because
37:24 is some potential out in the right? For material that's displaced into
37:30 water. So trying to understand the graphic relationships between deepwater setting and um
37:38 shell water setting. There's also an in trying to understand the evolution of
37:43 basin fill and maybe the relative timing it's due to high standard low stand
37:50 . And then deep water evaporates usually a time equivalent shallow water equivalent.
37:56 so they wanted to know how maybe of these basically evaporates correlate to the
38:02 equivalent units up on the platform. ? So with respect to evaporates,
38:08 the one tool that really helps It is the density log.
38:13 Because and hide writer gypsum has a density greater than anything in the
38:20 Right. It has a density over . Right. and hydrate is 3.3
38:27 gravity. That's obviously higher than which is 2.85. That's higher than
38:33 , Which is 2.72. So, easy to detect these evaporate deposits based
38:39 that density relationship. Right. And then we'll use that to correlate
38:45 Well, the well, but what you're dealing with basil carbonates and
38:50 All right. What's the most useful ? It's actually the resistance T tool
38:55 the reason activity will pick up on cleaner carbonates and then otherwise are delicious
39:00 Shelley sequence. Alright. And this a particular interest to Stokes When he
39:07 his dissertation back in the eighties, was trying to understand uh where the
39:15 and formation where the shale in the and formation which is a major correlate
39:21 sequence in western Canada Canada, he trying to figure out where the shale
39:26 coming from. All right. And way he figured this out was he
39:31 able to map these cleaner deepwater carbonate . See the here one of them
39:37 called the cameras member. But you another one here. You see how
39:41 response on the sp our receptivity is different than the shale. So,
39:47 those two put together a client of aspect for the arts and figure out
39:54 , where the shell was coming Right. So, let me let
39:57 show you that. Let me show the question here. Let me pose
40:00 question here and show you how he to answer the question. All
40:04 So this is the general fizz a map for the western Canadian sedimentary basin
40:10 basically a a U shaped basin that up to the north toward the
40:16 Alright. And it is fringed by deposition. So the blue here represents
40:23 water carbonate deposition and then the light represents the basin fill. Mostly shale
40:30 deep water carbonate. Alright, but going to see that the shale is
40:34 everywhere in that basin fill. People shot seismic across the western margin here
40:42 that's a prime expiration target for devonian . Okay, and when you look
40:47 the seismic data, this is what see shallow water carbonate dropping off into
40:52 water. There's this basically restricted what like an on lapping wedge of Arjun
41:00 . So how do most seismic interpreters this? What would they, what
41:05 they say? What would they Or where would they say the the
41:12 shale is coming from? And then would be the timing of shedding based
41:17 the straddle relationship? So it's Mhm. Come from the west.
41:25 . And brought in during high standard stand. Sure, yeah.
41:32 Yeah. Well, Exxon would say always during the low stand, no
41:36 what it is, right whether shale carbonate, they would say that slow
41:41 deposition. Alright, so the implication that the source area was off to
41:46 west and then you drop sea level you bring this stuff out to the
41:52 and you plastered along the edge during low stand. Okay, so marine
41:57 deposition during low stand when the carbonate is several exposed. All right,
42:04 , how do you test this? the first question you should ask If
42:12 low stand deposition, what would you to see here on top of the
42:17 ? See something you'd want to see of several exposure? There is
42:24 Okay, and then the second question be, I should be able to
42:28 find a source area somewhere to the . Nobody's ever been able to find
42:32 source area to the west. Those of shales. These are greenish sprain
42:38 calle, curious shales. Alright, source area. So what Stokes proved
42:45 using the reasons tv log and showing client of forming aspect of the iron
42:51 ? He was able to show that comes not from the west. It
42:55 from the north and it feeds in this from the north. But then
43:00 gets distributed by genus trophy currents around periphery of the basic well what sets
43:06 jesus trophic currents? The trade winds in the Devonian, the strong trade
43:11 are out of the Northeast principally. right. And that's what sets up
43:16 circulation sort of a counter clockwise That's what we call jesus trophic currents
43:22 they run like that. So the comes in from the northwest and gets
43:28 and plaster just along the edge of platform. Now you can argue whether
43:32 high standard low stand still. All . But there was no evidence for
43:36 stand on top of the carbonate. it's probably high stand where is being
43:42 in. Okay. But anyway, that's where the shale is. There's
43:49 shale here. Okay. It's all your normal deep water paleozoic basil
43:55 which is the world of bracket pods crime annoyed sitting in a wacky stone
44:00 Pakistan texture. Okay, everybody see I'm saying. All right. So
44:10 got to handle on this by using reason activity launch. All right.
44:14 here's what the rock looks like. is the R 10 Greenish Gray,
44:18 cal carries shale doesn't visit all. then here's the more typical basin fill
44:25 cleaner unit that he that he picked with the resistive Itty vlog that showed
44:30 client of forming aspect looks like this core. You see the institute Barack
44:36 the bracket pot still shell is still . That's what we call articulated.
44:42 ? That means to live there. where it died. Okay, So
44:45 is not transported material. And then see the little white specks here.
44:49 are pieces of paranoids. We'll cry . Don't preserve their body fossil usually
44:55 ? They break down into individual Okay, so that's one application of
45:01 receptivity log in a basin fill. now I hope you appreciate what I've
45:06 saying here. I started this discussion week, right. About the danger
45:11 using straddle geometries and for sea level . Right? I showed you from
45:17 modern hi stand shedding off the leeward of the Bahamas and Caicos, producing
45:24 apparent on lap wedge that's not due drop in sea level. Let's just
45:28 the day to day shutting during high . Here's the example we just talked
45:33 for the origin. All right. another example of something that produces a
45:39 on black, you have a carbonate adjacent to deep water basin accumulating deepwater
45:46 . The chalk is going to accumulate this and producing a parent on lap
45:52 chalk deposits in the gulf coast have misinterpreted the low stand apart deposits of
45:58 water carbonate brought into deep water during stance, applying the Exxon model.
46:04 ? And when they drilled it, do they drill the drill chalk?
46:07 didn't find any displaced shell water And then the last example here would
46:13 we don't have this today. But the rock record, it's very common
46:17 you come off these platforms and you into the into deeper water, you
46:22 through this force upsetting where you've evolved reefs. Right? And sometimes these
46:28 carbonate systems will shed material. And you get distal down lap of that
46:32 material that creates a parent on lap these pinnacle reefs. And people have
46:38 these to be basically restricted wedges. , a byproduct of with the interpreter
46:44 low stand deposition. And again, shallow water material up against the edge
46:50 the of the topography. Yet when drill this, it's all deep water
46:57 deeper water carbonate that's just been pushed . Okay. Non perspective. All
47:04 . You have to be really I hope you appreciate what I'm
47:07 You have to be really careful about this concept of basically restricted wedges to
47:13 change. Okay. Like Yeah, restrict. Yeah. Uh huh.
47:24 . It's a non laughing wedge. ? You've got Palin well, let's
47:27 back to the It's this All Yeah. On lapping wedge. Just
47:35 to the edge of the platform. . And what's one of Exxon's paradigms
47:41 interpreting seismic, They mapped this? is what they marked with the red
47:45 . Right? And they take this to be a nonconformity. The type
47:50 I can for me. Right? when they see this below the so
47:54 shell federal platform margin. All They always interpret that to be a
47:59 in sea level and then read deposition material up on the platform. Re
48:06 along the margin. The low which that's basically the low stand.
48:11 Okay, in the Exxon model. . And the problem is they treat
48:17 and classics behaving the same way All right. Read both papers.
48:24 difference. Okay. Hi stand shedding the norm for carbonates. We talked
48:33 this last week in the modern. , so you have to be very
48:37 about It's not like it's like everything we've been talking about so far.
48:43 . It's very rare that you can in on one aspect of a
48:48 I'll sequence and make a good environmental . Right? You've got to incorporate
48:53 of different observations. Right? The genesis the textures, the sedimentary
49:02 Things like that. Right. okay then with respect to deep water
49:09 evaporates. Remember we we had those last week. Right. For the
49:15 , We have three aspects of the model one was the deep water
49:21 Deep basin. Deep water. Deep in shallow water and then shallow basin
49:27 right? Where the depression was not deep and what do you typically produce
49:33 base and fill situation. Right. it's evaporate IQ, what do you
49:39 to have to have? Basically evaporates to have a sill right to periodically
49:47 that body of water. But then have to have recharged periodically in order
49:52 account for greater thicknesses. And then else do you need? You need
49:57 right kind of climate. Right? it's evaporate IQ, every time you
50:02 then you can evaporate that stuff Okay, so what's the net
50:07 The net effect are what we call upward sequences. They go from
50:13 So this could be calcite or dolomite and hide writer gypsum depending on whether
50:20 is out proper sub service. And you go back into carbonate. So
50:25 cycle contact is a reflooding where you new water. And so tell me
50:33 , what's the first thing that precipitates of a bucket of seawater, calcium
50:40 . Then what? So mhm. calcium carbonate gypsum around hydrate?
50:56 light. And then all those weird insults if you go far enough and
51:01 see here there's no hey light Because happens every time you re flood you
51:05 dissolve the hey light. Okay. so this is classical basin fill evaporate
51:13 carbonate and hydrate carbonate and hydrate. . And look at the DNC log
51:19 ? Low density for the carbonate, density for the and hydrate. And
51:25 good cycle contact. Is that transition high to low density just repeats over
51:30 over again. All right. And this is how they set up their
51:34 graffiti for the basin. Bill basin evaporates in areas like Western Canada,
51:40 musk ag formation. The basin film scag is classical finding upwards sequences.
51:47 right. In deeper water. All right. And then there's some
51:54 . There's interplay between shallow and deep . Obviously where things pro grade out
51:58 the basin. Sometimes you get an fingering effect because of the program nation
52:03 back stepping. Remember we had that last week, things will program and
52:07 they'll back step and then they'll program they'll back step. And you want
52:11 be able to in the in the you drill. You want to be
52:14 to mark that entertaining relationship. Because there could be some play potential
52:20 with a good strata, graphic right? If you have reservoir faces
52:26 with deeper water carbonates for sales. so the two tools that work the
52:31 are the process log in the gallery if you're based in Philly carbonates respond
52:37 the gamma. So, here's little more detail about the cyclist e from
52:43 water reef. I showed you a last week of the sort of the
52:49 bucket for red water. We're back itself out of existence. So here's
52:56 was a schematic cartoon. Here's a bit more detail. So you can
53:00 the prime reservoir units for red water the reef margin and re flat.
53:05 the dark blue and red. And you can see it also shed these
53:10 grain stones out in front as it out. And then you can see
53:16 first cycle builds up and out Classical internal probe additional geometry as it
53:22 up and then there's the main back right here. Right. We shift
53:27 . Well, look what happens along margin have incursion of deepwater carbonates up
53:31 the edge. We get the center effect. All right. And you
53:36 track that. You would obviously see would coordinate to but you see how
53:41 gamma rays responding to that dinner fingering the proxy log is responding because the
53:47 grain stones have great reservoir quality and shales are obviously impermeable, low
53:54 but show gamma response. Okay, sometimes those logs suites will help you
54:01 that in her fingering effect. All . All right. And then,
54:07 , this concept of composite cycles ah the story is when you have these
54:15 deepening effects, Right? Major deepening out of the shell water carbonate platform
54:22 , major deepening into based on live . The first thing you're going to
54:26 is incorporate. They are delicious carbonaceous at the base. You're going to
54:30 a kick on the Ghana. and then what do we typically see
54:35 cycle evolution? The lower cycles are because you have more accommodation to begin
54:44 . All right. And they are dominated by subtitle faces. And then
54:49 subsequent cycles become thinner thinner thinner with of that perry title deposition. Remember
54:56 term perry title? Yes. has nothing to do with title
55:04 That's what it be like small. , we don't use the term swamping
55:12 . Right. What did we Title flat or very shallow subtitle.
55:19 the title five complexes. We have restricted ponds and levees and things like
55:24 . So that's a that as restricted you can get in a marine
55:30 Right? Without going above sea So if you were to drill into
55:37 of that title flat, but you recognize the classical say levy deposits to
55:43 you're surely in a title flat. you hit the pond, but you
55:48 know if that's the offshore subtitle or pawn. We used the term perry
55:54 . That means we're in a highly setting. We don't know if it's
55:59 flat or shallow subtitle because we don't for sure we use this this sort
56:06 catch all term perry title. All . Right. Yeah. Well,
56:18 day we know where we're at. . So yeah, it would be
56:21 in the rock record. Right. would be telling be telling people,
56:26 not quite confident. I'm in a flat. I could be just offshore
56:30 the title flatten it really restricted subtitles or I couldn't It has.
56:40 Yeah. Yeah. Because that was the question. That was one of
56:44 questions. Right, Kerry title worst . Yeah. If you really want
56:53 understand what's going on, you've gotta rock data. No, I'm not
56:58 are not good enough, usually. right. Especially when you get into
57:02 parts of platforms where there's a lot variability, right? Members of cyclist
57:07 ? Whereas most of the cycle variation platform interior, right? These small
57:12 cycles, bigger scale cycles, interior, platform margin, no expression
57:18 cyclists out in deeper water. All . But you could have inner fingering
57:24 . That's not cyclist sitting, That's just setting back stepping, shedding
57:29 stepping. All right. Yeah, the other issue. Right? The
57:36 is not going to pick this All right. Okay. So let
57:41 let me just show you an example what I'm talking about here,
57:49 Mhm. Okay. And I don't why this is here. So,
58:06 the cartoon. All right. we have a major we come out
58:09 the title flat, we have a deepening. Right here we mark that
58:14 week as a major cycle contact agreed over shallow, but a major deepening
58:20 typically will show gamma response. And the first cycle relatively thick dominated by
58:27 shallow water carbonate faces. And then the second cycle contact. We built
58:33 the title flat. We go back deeper subtitles depot Rachelle a but not
58:39 enough to incorporate our delicious or carbonaceous . So no response on the gamma
58:45 cycle is not as thick and you see now we're changing the proportion of
58:50 water faces. We have greater proportion shallow water or peritoneal phases and then
58:57 turn around and go back into a thicker cycle. Again dominated by a
59:02 proportion of deeper water faces. That's turnaround point. That's the top of
59:07 composite cycle. So we would call of this the composite cycle but for
59:13 correlation, we would use this cycle in this cycle contact. Okay,
59:19 how we set up the regional time graffiti. So here's an example from
59:24 Devonian Western Canada. This is part a case study. We'll talk about
59:28 afternoon. All right. So the represents basically title flat or perry title
59:35 . The green represents restricted subtitle So we're coming out of a
59:42 cycle dominated by greater thickness of title deposition. Then we have a dramatic
59:48 right here. That's the major cycle . That's the base of the composite
59:54 . The lower cycles are thicker with green carbonate subtitle. The upper cycles
60:00 thinner with mostly title flat or perry and then we have the turnaround point
60:05 here. So this is the composite turns out to be 7-12 m
60:11 but those cycle contacts correlate all across platform for 30, 40 miles.
60:18 , so that's how we set up regional time strati graffiti. And then
60:21 see tomorrow that these small scale cycles correlate for hundreds of meters or a
60:27 kilometers. Okay. That's how you up the finer scale time strategic graffiti
60:33 you have the well control. All . And one last example here,
60:39 ray, then nancy log again for Mississippi and this is, uh,
60:45 Williston basin. Um, all of has been ground truth with core or
60:51 data. So I marked the oil shales and green and then the
60:56 represent the showing cycles and see the cycles are thicker with mostly subtitle carbonate
61:03 then the title flat or restricted all evaporated deposits start to come
61:09 Subsequent cycles are overall thinner with a proportion of red and then there's a
61:16 point. Okay, so with a shale. All right. That's a
61:21 deepening. That is a timeline for all the way across the Williston
61:26 Okay, so the boundaries are what we use for regional time strategy
61:32 and then we try to correlate the school cycles within that framework.
61:39 anybody understand what I'm saying? This a simple way, this is Wendy
61:43 way of, of trying to set regional time starting graffiti on a basin
61:50 or is you'll see next friday on reservoir scale. Okay, production.
61:59 , yeah. Okay, well hear tracks pretty well the reason activities tracking
62:07 pretty well. I mean, you want to look and see if you
62:11 make some sense out of any of long sweets, right? With respect
62:15 faces or cyclist city support. I can't tell you. I don't
62:27 . Okay. I don't know what poor food was. All right.
62:37 right. And then just to finish here and then we'll take a 15
62:41 break. The you guys are familiar the ways we use these modern log
62:47 here. I just want to make couple of comments about some of
62:51 some of the pitfalls, some of we've already talked about, right?
62:54 porosity logs. It's not enough to we have ferocity. You need to
62:58 what kind of ferocity, right. it effective with permeability or is it
63:03 and ineffective? Right fractures? don't create a lot of ferocity.
63:11 their role is in improving the P curves are nice to have because
63:17 break out mythology, but again, doesn't mean faces. All right.
63:22 point about spectral gamma ray, If you work dola stones, you
63:26 to run a spectral gamma ray because want to know if those Dolomites are
63:30 or not. And whether if they're , you want to know what's causing
63:35 . Is it being caused by which may or may not have anything
63:38 do with the oppositional setting. What it caused by the more standard
63:44 Soria, right? Is the gamma to that? That's probably more deposition
63:48 . Right? We get our delicious carbonaceous material. Same problem with image
63:54 sometimes, you know, these are people try to do with the image
63:57 , but there pitfalls to that NMR nuclear magnetic resonance technology. This is
64:05 mostly used in classics and carbonates to the proportion of micro ferocity versus macro
64:13 and then cT imaging uh, that are some of the applications, but
64:17 imaging is controlled by the price of . Right? Nobody does scanning.
64:23 does cat scanning On rocks when the of oil is not over $100 a
64:28 , essentially. So you don't see using that much right now, let
64:34 just show you some of the All right. This example from the
64:38 in west texas, uh ST andrews the big booming Permian reservoir that produces
64:44 from carbonates and this is above the interval. And uh, so companies
64:50 not gonna, they're not gonna look , they're not going to collect rock
64:54 for regional correlation. So what do use? They use the they use
64:59 p curved to pick up these silt . These sell stones have three going
65:04 there probably low stand deposits right? silk moved across the carbonate platform during
65:12 . And so they use the soul for regional correlation and not spend time
65:17 money pouring and trying to use the data. Okay, So that's one
65:24 . And then the, the image of course. Uh, people want
65:29 see cursed effects and things like And usually when you see image response
65:35 this, this is taken to be , some sort of cave deposit.
65:40 . But we talked about the brecko last week. Wretches by themselves.
65:46 prove some barrel exposure versus barrel You have to look at more of
65:50 rock to figure that out. All . And then cycle contacts. All
65:55 . Remember our definition deepwater faces abruptly relying a lighter cleaner colored
66:04 Sometimes you can pick that up nicely the image log you'd also probably see
66:08 sun a on some sort of law or cross your response pressure solution
66:15 Remember what we call this new modular is a by attributed to begin
66:21 And then pressure solution on top of . And you can see how the
66:26 log picks that up. And then an example from the Permian in west
66:33 where the bureau in Austin interpreted core . Of course they're comparing two different
66:39 here, which is that's a red right off the bat. Right.
66:44 at the the different well, for image log in the different wealth for
66:48 core really. But anyway, what trying to say when you see this
66:54 fabric, that's a title flat Right. Where else can you get
67:00 carbonate? Yeah, yeah. In reef. But okay. Where
67:15 where else is it more likely to greater vertical thickness in a title flat
67:21 the basin? Right. All But here they relate this to title
67:26 . They're saying this is the millimeter stratification. Actually what I see here
67:31 more precious solution. You see all fine scale and I see more finesse
67:36 here, then maybe you pick up of that finessed right here.
67:41 But again, this is not a match between the rock data and the
67:46 log because they're comparing two different But this leads me to share with
67:52 . One of my experiences or I a client called me up once working
67:56 pennsylvania in the four corners area of western U. S. He
68:01 record this well and he called me and he said, I want you
68:06 describe this Corer. It's 100 ft of laminated title flat. I
68:12 well if you already know what it , why do you want me describe
68:15 core? But I said, Why do you think it's a laminated
68:19 flat? Because we have an image looks just like this image log right
68:24 , 100 ft of fabric to look that. Again, that doesn't make
68:30 for a title. Is that Remember our title slap discussion title flat
68:36 fabric was limited to where the Right. And the levy just makes
68:42 a small proportion of that overall Flat succession. It's highly unlikely you're
68:48 going to stack together 100 ft of . Right? Because you're already you're
68:54 at sea level. Any minor sea level is going to terminate that
68:58 and you're going to go back into subtitle borough carbonate. Right. So
69:03 are you more likely to preserve this a basin? Okay. So I
69:09 and he gave me, he shipped the logs and and I went and
69:13 at the core And it was 100 of black limestone with no lamination.
69:20 it looked just like this image. . That's where the tool can
69:25 All right. So you have to really careful. And just assuming that
69:28 you see on an image log is representative what the rock looks like.
69:33 right. And then this last example there's a again, they're comparing two
69:41 wells. I lost a lot of for the birth of the bureau when
69:46 published stuff like this. And I I lost respect for whoever reviewed this
69:50 . Right? They should have caught as well. But but here,
69:55 you see the borough fabric. And and this is these are those
69:58 tempest. It's we talked briefly about week, right? Backfilled burrows during
70:05 deposit of the different texture. And here they say that's the same
70:10 but if you show this to most log analysts, what would they call
70:13 dark these dark areas. Doctors. , well, it could be a
70:21 could be a denser nodule surrounded by porous fabric. Or it could be
70:27 , right? Could be a buggy system. Yeah. Sure. Something
70:34 leads to cavernous ferocity. Right. . Just continues solution. Enlargement.
70:42 . Anything is possible. What are are receptivity logs. Right. So
70:48 they're looking at a changes in the . So, and I mean,
70:56 you want to ground truth with the data? They didn't really do that
70:59 because they're comparing two different wells. they're just they just made the
71:05 When I see this in the I'm going to call this backfill
71:10 Right. And not porosity. And NMR logs. The NMR technology is
71:18 used more in classic Senators and but there is good potential and
71:24 All right. Especially in cretaceous systems you have this by model porosity,
71:28 of microprocessor, lot of macro And how the bumps are expressed on
71:34 log tells you whether it's a bi poor system where you have to or
71:39 it's skewed to the left. It's uh microprocessor. If it's all skewed
71:44 the right, It's mostly macro porosity I got involved in a big study
71:50 Anadarko back in the 90s Where we at 5000 ft of course through the
71:55 trend Edwards trend in south texas. looked basically spent a week in the
72:01 warehouse in austin looking at all the available. And we sampled all the
72:07 for porosity, took standard cord we had them analyzed for processing permeability
72:14 then Anadarko took the plugs and had run through the NMR to calculate the
72:21 of macro versus micro porosity. And we did a double blind study.
72:26 didn't share that data with me. gave me the core plug. I
72:29 a thin section off of the edge made thin sections and then I estimated
72:34 thin section the amount of macro versus porosity. And you see we came
72:39 with a correlation coefficient of .71, is pretty strong. All right.
72:44 this is this is what I I used a simple white paper technique
72:49 pick up the amount of microprocessor. look how you would miss that micro
72:54 in the standard thin section right But look how you pick it up
72:58 the white under the white paper All right. So you can see
73:02 estimate of macro versus micro porosity. you see the measured P and
73:07 And P. For the for that . And then here's the lagoon.
73:11 stuff which has poor reservoir quality. ? No permeability because it's all micro
73:16 dominated. Where's the microprocessor. You see in a standard thin section but
73:21 can pick up the blue hue and grains and in them a critic
73:26 Okay, so that's why all of of these numbers at the top for
73:44 or mine. Mhm. Pretty 2.71 correlation coefficient is pretty strong.
73:54 we had a pretty good correlation between I observed and what the NMR tool
73:58 suggesting in terms of macro versus micro . Yeah. Mhm. You are
74:25 pretty good. Yeah. Good. huh. Yeah. Okay. Any
74:36 other questions or comments about the longer this suppose it you did a carbonate
74:54 physics thing. Yeah. Right. said she was this is okay iris
75:10 . It's supposed to be what? physical model that gave us so
75:17 He gave us so much of the just to show the correlation the
75:25 Yeah, basically it was a way determining with dialogue information whether you have
75:31 force systems in which one is Yeah. And why do you why
75:36 you care in a oil water system you've got a lot of micro porosity
75:42 a lot of effective inter particle We had we had this discussion early
75:48 our this goes back to the porosity that we talked about the first day
75:54 when you got to buy mobile poor with a lot of microprocessor in the
75:58 but you have effective inter particle processing the grains. Where's all the bound
76:03 ? It's in the micro porosity. the oil? It's in the inter
76:07 ferocity. But you're resistive. Itty reads that high water saturation within the
76:14 Micro porosity. So you end up high water saturation of 60-80%. And
76:21 everyone would conclude, oh, that's a water wet reservoir.
76:26 Yet these are the famous reservoirs that oil water free because it's all irreducible
76:33 . That's why you want to All right. And what are the
76:37 major geological time periods where you tend see a lot of this by mobile
76:42 ? So cretaceous all around the You see this in the cretaceous,
76:47 kind of relationship and then the tertiary has a high percent. For support
76:53 whatever reason. The tertiary shows lot microprocessors, but that doesn't mean it
76:58 occur in any geological system. It . All right. But just if
77:02 had to characterize the two time we see a lot more microprocessor.
77:07 the cretaceous and it is the tertiary tertiary right areas like South East
77:14 famous for a high degree of micro . All right. All right.
77:21 take a break. We'll come back 10-3. All right, Yeah.
77:28 talk a little bit about seismic expression carbonates. Alright, Utah I'm going
77:34 stop the recording. Mhm
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