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GEOL6381/4382 Introduction to Petroleum Geology - Van-10
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02:03 Hello. A million. Hi, . Sure. Hi, everyone.
02:24 . Hello. Okay, E guess got all the grades out to
02:35 Um, somebody's actually asked to see test. I don't have any test
02:40 to show you. It was all online. But if if you do
02:43 a question about your grades, feel free to send me an email
02:49 I can, you know, send back information to help. Help?
02:53 explain to you where you made your . Okay, I'm going to share
03:04 screen. Assume it's recording. Okay. I gotta drop off on
03:30 coffee cup. Lord in trouble. is they don't give you a lot
04:00 room to work with things there. overcame the problem. Okay,
04:13 for this lecture, we're gonna this gonna be more appraisal. Yeah,
04:23 we're going to go over the mapping Volumetrics exercise, which is the last
04:27 you have to do. I think an important exercise. It might take
04:33 a little bit of time, but to focus on drawing it, not
04:38 to do it some some way When you start calculating reserves can't.
04:45 you think about trigonometry. It can you get through the volumetric part very
04:51 , and it's sort of designed thio help you understand what it is you're
04:58 in three dimensions and what's actually going . And of course, for many
05:06 we've used simple structure maps and ice maps to help us visualize things in
05:11 dimensions. But now we have these that try to image it displays three
05:19 , which makes it hard for Thio focus. Our mental power actually
05:27 in our heads, which is where which is where our decisions get
05:31 its inside of our head. It's in the computer and and it's,
05:36 think it's very instructive Thio to get opportunity to do something where you're actually
05:43 in two dimensions. What is three and and therefore exercising? Uh,
05:51 incredible human brainpower thio to actually conceive things inside your head in three dimensions
05:58 actually looking at something that really is dimensions. I mean, you
06:04 we have these great eyes to help see three dimensions, but what's important
06:09 to be able to think about that dimensional object in our brains and be
06:14 to sort of project of where things gonna be within that three dimension volume
06:20 having toe have that three dimensional volume rationalized or realized in front of
06:28 Okay, so okay, so kind the way we do this is with
06:38 lines. Most geologists should know what contour line is, but just to
06:42 sure, their lines of equal value terms of, uh, some reference
06:49 a datum so it could be an above sea level or an elevation below
06:54 level, something like that. And course, that's what geologists normally
06:59 And the ups and downs of things us see the relief off the earth's
07:06 , for example. It's a very example, but in the subsurface,
07:10 trying to figure out the ups and of surfaces, not planed off surfaces
07:17 eroded surfaces. But surfaces that have preserved has pretty much originally flat surfaces
07:23 sedimentary rocks that due to structure, emotions or some sort of subsidence and
07:31 things that can create curvature and dips also bends and uplifts, or
07:38 you know, like an antique line a sin. Klein all these things
07:42 Post deposition, all. But they're in general erosion unless it's an erosion
07:47 surface that's buried and preserved. It's lot of things that we think
07:53 including cross cut relationships and on the , are completely reversed in the subsurface
08:02 we're not looking, had things that been subjected to Pena play nation or
08:09 of the Earth by erosion. You , we're almost catching them, except
08:16 you know, we might even catching conforming. But for the most
08:19 we're catching structure that's developed with, , subsidence and tectonic activity acting upon
08:29 . Okay, so and that's what do is structure, maps.
08:34 of course, the other type of that we use contour lines is ice
08:37 maps or icy core maps and, , ice a pack maps. They're
08:43 to be, um, contour maps give us an interval of thickness.
08:48 not a surface, but it's a inside of inside of two surfaces or
08:54 surfaces. In other words, there's closure for the most part of an
08:59 pack map. You may not have all on your on your page,
09:03 eventually some thickness is gonna end in direction and the and of course,
09:13 , purists, uh, we'll talk Isaac or map, which is usually
09:19 t two vertical thickness versus a nice pack, which is true thickness through
09:26 strata Graphic thickness tst, in other , And if I have something that's
09:33 like this and have a well drilling it, that vertical thickness straight hold
09:38 through that vertical thickness is still gonna greater than if I went through it
09:42 way. Uh, sort of were only through the formation with the
09:47 you know, straight 90 degree angle in there. Uh, that's the
09:51 time you're going to get TV t T S t equal the same.
09:55 if there's any tilt this way with bed or any tilt this way with
09:59 well TV T, I's gonna be little bit different than true strata graphic
10:05 , which is what we're trying to out. But anyway, most of
10:09 we use we just call it a accord, a nice APAC map,
10:15 , and a zloty, as people in the back of their minds that
10:19 they have significant issues with dip. need to make sure they correct for
10:23 dip of that bed. Uh, always, if you have a deviated
10:28 , you need to correct for the in that well on you and I
10:33 pretty much call everything an ice APAC . But in some cases, it
10:36 actually be a nicer core map, , from a purest standpoint. And
10:42 other things we could do, like therms, isil, It's isobars,
10:49 , and we can do things with . Celebrity. Things like that are
10:56 chemical measures that we might have in water column. Okay. And this
11:02 just showing you how we translate a surface onto a contour map so that
11:11 a geologist sees this in two the surface up here, he will
11:16 that it means it's depicting something in dimensions. It tilts like that.
11:22 that's what I mean. Being able look at a two dimensional map and
11:28 in your mind, be able to that that's a tilted plane. And
11:34 it was curved in here in any , you know that it had
11:37 In other words, it wouldn't be flat plane. It would be an
11:41 surface. And this is just showing against some simple things. Looking at
11:50 in two dimensions, you see a like this the closer these lines are
11:56 . That means you have a greater of change in the tilt. And
12:01 is Let me do this. This here is lesser rate of change in
12:10 tilt. There's a dip here, it's za low dip. When we
12:14 ready to change its quicker, you to put the lines closer together,
12:19 to signify that this is going In other words, we go from
12:24 . Okay, so we've only we've gone up. Uh, this is
12:28 subsurface. So we've gone from minus minus 7300 over this longer distance,
12:35 over a shorter distance, we've increased rate and we know that the dip
12:40 coming up in the height is coming on that surface. And this is
12:47 just sort of the mind exercise to a look at it yourselves and think
12:54 you know, this. This is planes, so they're going to be
12:58 distance These air curves in a certain and kind of flattens out down
13:06 But it's very steep up here. could see that. Here's a compound
13:11 that Z flattening out from here. flattens out in this direction from
13:15 It flattens out in this direction, it's deep in the middle, and
13:19 something that's convex. And, of , eventually the roll over starts to
13:23 steeple. The top starts to get , and it could be a little
13:29 complicated. Could be a lot more than that, but this gives you
13:32 idea what goes on with rate of and dips. And here's looking at
13:38 in the map view and then flipping over and looking inside you.
13:44 uh, you know, it may like a simple thing to everyone,
13:48 there are actually I've heard a couple different numbers, but one of the
13:54 I think is probably realistic is about of the people in the world have
14:00 hard time visualizing in three dimensions uh, and so inside their
14:08 And so if you happen to be of those people, you need to
14:11 a lot of attention to, something like this. And even if
14:16 if you don't have difficulty, it's important when you're dealing with two dimensional
14:23 that air depicting three dimensional, often , it's good to look in different
14:27 . In other words, this is down, uh, into something,
14:32 this is looking at the side of . If you look, look
14:36 it's something at the side of something . You have a better concept of
14:41 that three dimensional surfaces tryingto. That dimensional depiction in two dimensions is trying
14:48 show you that it's something that spreads like this on two axes. But
14:53 spreads out like this into different axes . That's uh huh. Two overlapping
15:00 . You end up having, three dimensional concept of what's going
15:05 Okay, And here is, this is kind of a reverse image
15:09 one of the slides we had last , but it's showing something like an
15:14 Klein with a little pinnacle on the end of it, with four way
15:18 . And that was something I mentioned that sometimes when we have these really
15:22 things, it seems Smalley oftentimes or in shape, they don't have to
15:28 . And of course, with vertical , we can do all sorts of
15:32 . And by that I mean, , if the distance here his foot
15:37 foot the same as the distance a lot of times you wouldn't even
15:40 able to see structures close up because were just completely flat now. And
15:50 is, uh, also out of tear pocketbook and just showing one method
15:57 depicting depressions where you have contours like and you can see that the sub
16:06 this is subsidy with the minus, going down. And and,
16:15 what I think you really should develop a sense that when you see these
16:18 going down, you automatically know it's other words, it's getting greater from
16:22 level eso in the subsurface that's going Also in our industry, a lot
16:27 times, people leave these minuses out we're in the subsurface. And,
16:35 , everybody should assume for the same we don't put pluses on maps.
16:42 , when it's above sea level, don't put the minuses on there.
16:46 something something gets larger above sea This would be up, but otherwise
16:55 subsurface. It means down as we larger and larger numbers because we're going
17:00 sea level and depending on what company on or what kind of display your
17:08 Thio produce. Uh, somebody might that you put that minus in there
17:13 of course, then you need to it. But it's really important in
17:18 visual sense or visualization sense that you to understand. Ah, bigger numbers
17:25 down in smaller numbers mean up in subsurface. And here is just,
17:31 , kind of what I'm talking And this is a, uh,
17:36 sea level map, and I didn't the minuses in, But a lot
17:38 times you'll see this because we know in the subsurface. We don't bother
17:42 put the minus on, So the the number, the deeper goes.
17:47 when we're making these contour maps one things ah, the computers and people
17:55 is they start looking at equal distances everything. And, you know,
18:01 map might start doing circles around this because because it doesn't have any data
18:07 . And so it's going toe do to get you over here into over
18:12 that is. But when your hand them on again, I think this
18:17 This is a very worthwhile excerpt exercise anybody in the industry. Anybody working
18:25 . And of course, the guys wrote the book and taught itself thought
18:29 , too. Um, you, and this was, of course,
18:34 a long time after I learned how do this sort of stuff, but
18:37 have clusters of data like this and you have clusters of data,
18:42 in maximum control, that's where you putting this in. And of
18:46 this is just showing you I have that these WellPoint's you might have a
18:52 line like this for that particular If you've identified it, you could
18:56 values along that seismic line so and to it. But you do the
19:02 with the most control first, because kind of gives you an idea of
19:05 gonna happen. And, uh, other words, I'm not trying to
19:11 a bunch of circles to get over to 16 ft, depending on whatever
19:16 contour line is. I just I that this is going kind of like
19:19 . This is going kind of like . So I can almost connect the
19:24 and this falls into place where it . Same thing here here is 25
19:31 this one, you know, is have to kind of come down like
19:34 and then go back up 2, and rather than, you know,
19:40 some kind of funky thing around this because it's low and it looks like
19:45 should be equal to this. You to just increase the bend in this
19:51 to get it down a little bit they could get 25 around it that
19:55 and bring it on over here, , over this way. Okay.
20:02 of course, Contours style has a to do with, um, kind
20:10 what this is what a computer And this would be what a geologist
20:18 . And then what a clever geologist is also that it might really be
20:22 this and that closures or not are required. If this was a nice
20:27 map, there's gotta be closure But you may not It In other
20:33 , if I cut it off here cut it off there, I might
20:35 see the closure for all the But here you can see,
20:43 on the structure map, and this a subsurface structure map. I'm guessing
20:50 could It could be a Yeah, thinking this is a subsurface structure map
20:56 the minuses on it. And the is, is that disclosure that you're
21:01 here, um, doesn't have to . And also this undulation. This
21:11 kind of putting geological perspective into You might have some idea that there
21:17 be features like this, as opposed just a something that's always a
21:23 something that looks like a bull's Nature doesn't usually do this except for
21:28 like pinnacle reefs or path A listen things, things like that that we
21:36 , um, we actually don't normally those kinds of features. Okay.
21:42 basic contouring styles air called mechanical equally spaced and interpreted, and the
21:53 I usually do My work is a of ignore these two, which are
21:57 similar, and they tend to create kinds of things. Uh, that
22:04 up having closure around the data set you have without ever thinking that disclosure
22:12 not even exist that we could have with the strike along here and dip
22:19 way and dip that way. Strike here, Dip this way. Dip
22:22 way And there's no closure. Here all. In other words,
22:28 Parts wide open. In other there was oil and there could leak
22:31 this way or it could fill in that way. Okay. And
22:39 of course, this is kind of forced thing where you're trying to keep
22:41 parallel. Mrs Similar. Ah, you're trying to keep them equally
22:51 And when would I like to see always keep thinking about uniformed dip in
22:58 this exercise, you're not looking at big enough map to see it.
23:01 when you do regional maps, just little concept of trying to keep
23:08 dip grossly uniformed. If I can it that way, um, sort
23:15 roughly uniformed in an area because, know, you have a big part
23:18 the earth in a regional map that's in a certain way. Uh,
23:24 know, it really has a big on keeping you from over closing
23:33 and I think that's a really danger a lot of the computer maps that
23:38 do parallel and equal space. You ask him to do these different ways
23:43 there's a pop down menu, but when when were hand drawing? I
23:48 it's best toe have sort of a approach where you have data sets like
23:55 get mechanical in here and try to these things equally spaced within.
24:02 basically, you're tryingto interplay between points this. Like when you figure out
24:08 the dip is, what what's going to keep the dip from changing the
24:13 and keeping it kind of, sort of realistic, you know?
24:19 other words, do not create, , changes in dip. Unless you
24:23 a reason why you need to like , you would need to change the
24:26 a little bit and then, this interpretive thing in here when you
24:35 , you can always do that, sort of go with mechanical, but
24:41 do something that looks a little more like that. And so here's what
24:47 mechanical looks like in the book has mistaking it clears can be It's a
24:54 mistake, but this line should be between these two points and not less
25:02 halfway between those two points. And if I was doing this mechanically,
25:07 wouldn't draw it like this. And it's showing you in parallel is trying
25:15 force the parallel lines. But you see the dip changes by forcing a
25:21 the paralititan thio it. It's it's the dip here from over here.
25:27 other words, this is dropping down dip. This is raising the dip
25:30 . And but the idea this is to kind of force that these lines
25:36 of look parallel. It's kind of impressionistic art, you know, you're
25:41 these crazy lines, but you get back. It looks a certain
25:45 Okay. And then here is what can happen with parallel contouring by
25:54 then, of course, you can changes in dip here, and and
26:01 can cause problems, too. But is one of the things about um
26:09 is probably why a lot of people you can't do anything with geology
26:13 You have to have geophysical data uh, this is an unrealistic concept
26:20 all this. Sure you don't have lot of data but heck, I'm
26:24 geologist. I'm supposed to figure out going on with whatever I have,
26:29 with everything I think I need, , if you put enough well holes
26:34 here, you've probably spent too much to make any money. So you
26:38 have to think about how to interpret single point information in a two dimensional
26:47 so you can figure out what the are and where the closure is.
26:50 this this is, ah, prime have parallel mint. Uh, mapping
26:56 can create all these, uh, little closures that might have oil and
27:02 in them. And maybe none of exist. Could be just like this
27:07 right here. You know it Zanno . It just kind of over
27:14 Parallel izing your maps. And that's word. And here is equal space
27:21 a little different. Uh, then of them, but, you
27:25 and you're getting a little bit of change in dips, but you're you
27:30 , whether or not it's exactly parallel not You know, the underlying
27:35 Although every time I look at the I look at this somewhere, it
27:38 like parallel but with sharper corners. so when you're doing equally spaced or
27:46 or less mechanical. Ah, you to do something like this between
27:52 You have a well there and well , and you have a depth here
27:55 the depths here and you can you figure it out. I have one
27:59 these kinds of things. I don't you could even buy them anymore.
28:04 it's a contour spreading divider, eso you have equal points and you
28:11 like if you scale it on a and this is 450 this is,
28:17 know, something off 100 taking kind move these things around, and that
28:24 a whole lot easier to draw But you can also do it with
28:26 ruler, whether it's one of these scales or if it's just a regular
28:34 . But when you have an engineer , you can flip it around until
28:37 tends to work for the scale you're at, okay, and then interpretive
28:48 . You can see here this looks like a real geological feature. It's
28:52 far off from that. It's definitely like that. A little bit like
28:57 . And this mechanical thing is So I usually start was something that's
29:01 to mechanical, and and I add internal interpretive flair to it when I
29:09 , you know, you might not be able to do that.
29:16 uh and so we're gonna be using and then try to use your interpretive
29:21 you can. You can see her contours off again, Uh, when
29:25 making your maps, but you have really simple structure to map. But
29:30 the same time and where you decide put a a line of contour can
29:41 dramatically changed the volume of your reservoir I'll mention that how that happens when
29:47 get thio the exercise itself a little . Okay, so in this
29:56 one of the first things you have do is make a fault plane,
30:01 , and you need the fault plane because the fault plane is gonna be
30:06 plane that intersects, and most of faults are planer more or less plainer
30:13 a map. They often look curved the surface that you're mapping against it
30:18 curved. And if you have a with the curve surface on it that
30:24 it. It's going to make like the structure goes up and down and
30:29 like this. Uh, if you down on it, the fault will
30:34 like that. And so a lot the curvature and false has to do
30:38 surface that intersects with it. So we're looking at a map that has
30:41 drawn in map view, they will look curved in your You've got to
30:47 see this, uh, knowing that have, ah, plane. And
30:51 when you try Thio, uh, with your structure maps, you're going
30:57 see that it, but actually will up on your map is gonna be
31:01 curved surface for the fall When you a fault. That's a plane intersecting
31:07 curve surface. And hopefully that will apparent to you as we go through
31:16 and you'll end up making a fall map and a lot of students forget
31:21 do this. But when you make fault plane map, it's important for
31:26 to measure what the dip? the actual dip and write it down
31:30 the direction When you do this it's almost dipping to the south,
31:37 not quite in a lot of Just go ahead and say South
31:43 you know, get one of uh, nice little protractor things that
31:48 you to measure things. And maybe have one already. You can also
31:55 it with math, but I want to be able to come up with
31:58 strike and a dip and the The dip is something we're going to
32:03 . The actual dip angle is something we're going to calculate, uh,
32:09 a method that's coming up in the . And but the strike and the
32:18 , of course, they're gonna be to each other. And I want
32:21 to try to figure that out to other words, I'll ask for this
32:26 I'll ask for that. This one going to calculate for this exercise,
32:33 it's gonna actually help you make your , plane man, and then try
32:37 measure. But what? The deviation the strike is off the east,
32:42 or north south so that you can out what the dip of the fault
32:46 because the dip of the fault will perpendicular to the strike of the
32:53 Okay. And the reason the reason it's so important to do this is
32:59 that fault plane has a big impact the volume of your reservoir. And
33:11 can have a big impact, particularly you have this low incidence angle here
33:19 and you come in, it could just like a flatbed with oil.
33:23 contact. In other words, this a flat surface. You tilt this
33:27 into it, that wedge gets In other words, that this dip
33:32 in other words, gets closer and to the vertical, the amount of
33:38 formation that you're half ing in terms volume, eyes gonna increase, give
33:46 if you raise this up and reduce dip of the bed as it intersects
33:50 this, it's gonna change. So of one of the things in this
33:54 is that outfront you're going to know a flatbed can have a really big
34:01 effect. Excuse me. Wedging effect the oil water contact down here.
34:08 , but if steep, more steeply , one here will have a lesser
34:12 water contact, reduction in volume and greater fault contact reduction in volume.
34:20 these two points air critical that point there. And that point right there
34:24 critical because this this is, sort of the bottom limit. This
34:30 where this point right here is where go from. Um zero wedge on
34:39 fault to maximum wedge appear. In words, it's completely gone. We're
34:49 . Likewise. This point in this , some kind of in two dimensions
34:54 outlining a trap is away. And point at this point, this shows
34:59 the bottom of the reservoir on this you the top of the reservoir intersecting
35:04 and that shows you the with or area in which your volume is going
35:10 be half in the reservoir Because the water content This shows you where the
35:15 is relative to the fault. Now changed the dip on this. This
35:24 volume will get smaller and that volume get larger in terms of what's going
35:28 be cut out. Okay. And , here's the solution. Thio this
35:39 way of sorting out what your fault looks like and there are there are
35:46 ways to do it. But I it's it's kind of important to follow
35:51 and think about what's going on in dimensions when you're doing it.
35:56 uh, I think it will give a better idea of what's really happening
36:02 that fault plane and how you're going figure out this fall plane.
36:06 Now, this is gonna be the strike line, So this is sort
36:12 an East west strike line, and is going to be probably close to
36:16 . But to get the contours right everything, you need to know exactly
36:20 it is and to get the dip , the dip of the angle,
36:23 direction of the dip of the angle the fall plane and the strike you're
36:30 need to resolve this, and it's , and then it's going to help
36:34 create construct while you're going through Ah, fault plane man. And
36:39 start out with all these funny points critical thing here is you need to
36:45 three wells with a fault cut. here you have a well, with
36:48 fault cut. There you have a with a fault cut. And there
36:51 have a well of the fault cut your data set, you will have
36:54 fault cuts. Do not worry about it cuts the other wells because everything
37:01 work out in the mapping routine. , you just need to to look
37:07 the fault cuts that your provided and , of course, if something is
37:14 like this and, you know, already could read what this is
37:19 But as I go north, the planes coming shallower. So any well
37:25 of this, the fault will cut above the the unit that we're gonna
37:31 focusing on that were mapping, for . And so So that's that's kind
37:39 what's important course. This this isn't one mapping surface, but it's actually
37:43 cuts these things, and when we the map on top of it will
37:46 able to see how it cuts our . But the fault north of that
37:51 going to be in a formation higher the false south of that are gonna
37:56 lower in this section that we're actually at and not the surfaces that we're
38:03 . Okay, so the very first , if you have three wells,
38:08 start out with three wells, and look at the the one with the
38:12 fault cut and the one with the fault cut. And you draw a
38:16 between those on your base map and got a base map at a certain
38:21 that's going to help all of this out. Right. So you need
38:24 print out the base map at the , Uh, that it's done on
38:29 slide, and, uh, and everything will work out. Okay,
38:34 that's the first line you draw and , um, from lowest the highest
38:42 gonna be looking kind of for from the farthest down dip to the
38:48 up dip cut. Okay, then you're gonna pick a point. It's
38:58 distance, uh, between the distance of the depth. In other
39:06 that the distance and depth here is ft. So on the scale of
39:11 map, find a point out here 1000 ft, and you can do
39:17 with a compass if you want. you could just, you know,
39:20 a ruler and measure it out according the scale. And, uh,
39:25 could put the point up here, you could put the point down
39:29 But just send it off somewhere away this fault. This this well
39:34 And when you change, the angle is going to change all the
39:39 uh, three dimensional aspects of this that it compensates. In other
39:44 if I pull it down here, going to do something to make the
39:47 of this work right. If I it up here, is gonna alter
39:50 of the geometry that will will auto it? Uh, if I put
39:55 up there, So just here it's exercise is not gonna be 1000 ft
40:01 gonna be something different. But whatever difference in depth is here, you
40:05 a market out here and come up a point d? Then you can
40:12 that point d with point B, now you have this nice little
40:22 and then you want to take a right here. Here's 400.
40:33 this is between the fault cut and and C. So this well and
40:36 well is 400 ft. So I to basically like if you take this
40:42 stick and move it down parallel like . To where? The distance between
40:48 and here. Uh, excuse The distance between here and here is
40:53 ft. Then this line comes down right there. And so you just
40:58 it down to that e. So is the next one that you're gonna
41:01 400 ft away. You figured it from here, pull it down to
41:06 and then you're going to draw that across. And this is parallel,
41:11 though this line isn't orthogonal to But you have a parallel line and
41:16 it intersects right there is really because that's what you do next.
41:22 draw that line across here to this , which I didn't do perfectly.
41:29 this would be, um, the , uh, of default. And
41:39 also one of your first contours at ft. So in other words,
41:46 already have my fault plane map Kind figure it out. Now, I
41:50 have to contour in between him, we want you to come up with
41:54 dip angle the angle of the dip the fault. And to do
42:01 you just draw a line is perpendicular this, and it comes up here
42:12 shit. The actual map that you is a little looks a little different
42:17 this, but from a draw up fault to this line right here,
42:23 it happens to be, may not exactly like this, But wherever it
42:26 to be perpendicular to that strike okay. And when you do
42:37 you had 400 ft from that l to make an end point. And
42:43 angle right here? Not there, there, not there. The angle
42:48 here is the dip of your fault . Okay, then is we,
43:04 uh, get to that point. know what the dip is. So
43:06 have that you can you can answer dip. Like I said, this
43:10 the original line. It's not perfectly by me, but but you can
43:14 it, um, in other equally distance lines. Here's the line
43:21 . Uh, parallel to that line be your 2000. This is your
43:26 . You've got to put enough contours here equally spaced to go to
43:31 24 23 22 21 2000, and that's your ice. That's the fault
43:39 map that you're gonna be looking Like I said, it's it's tilted
43:44 little bit different than this, but gonna look very similar to this.
43:47 then, uh, here, I've that you can add above, and
43:51 can add below to increase your fault map to work to your to your
43:59 advantage, to see how it intersects the surface you're mapping. So what
44:06 need to do is make a preliminary map. It is going to be
44:11 in some direction towards the South. and it's a normal fault. So
44:16 deeper in this direction. And I'll you up front, the trap is
44:21 be up against the fault on the side. So you want to draw
44:25 you get all this. If you at the whole map, you have
44:34 these data points, and I could you roughly the faults going to be
44:38 here somewhere. In other words, of these will be south of the
44:41 . Most of these will be north you start making your surface your structure
44:47 . Make a preliminary map of the first. Don't mess with these yet
44:52 you don't have all the information you . You need to know what the
44:54 cut is doing to the surface based this set of of of contour
45:03 which will then give you more points help you draw this better up
45:09 And that's because this is the down block. I want to figure it
45:11 first. And that's where the trap . Once we figure that out points
45:17 the fault where these lines of contour , it will actually help you give
45:22 more data points to contour that Yeah, that went the wrong
45:31 Excuse me. Sure. Eso on geo geometric method that you were showing
45:38 without working it out. I assume it it doesn't matter which two wells
45:44 choose. It'll always work out the way for the third. Well,
45:51 e. If you had a bunch wells with a lot of fall
45:55 you could pick whatever one you want . But you're only gonna have three
46:00 and I'm only going to give you fault cuts. Eso you don't have
46:04 struggle with this. But normally you pick the deepest one in your data
46:07 in the shallowest one that had that fault in it. And then you
46:13 one in the middle. So if had a lot of points, you
46:16 have ones in the middle. But need to pick the deepest in the
46:19 one first. Okay, So shallow. And then the third one
46:24 the middle. And then when you your D line, yeah, it
46:32 an equilateral triangle with the shallow as in the deepest Well, I'm gonna
46:36 thio unshared. My, um I a mistake again with this,
46:45 the way this system set up, drops out my cursor there. I
46:52 it. Uh, and now this fully expanded. I can't go back
47:00 this mode. Yeah, the wonders sure. Okay, now I ask
47:12 question again. Okay. So, , the d the point D When
47:19 take that line out there, there's ft in map view. Eso Those
47:24 both 2000 ft. So it makes lateral triangle regardless, Um, I
47:32 so. Yeah. I don't know sure, but it doesn't matter where
47:36 put this, because it's gonna be this, and then this will come
47:40 it, Okay? And, but the key is is that you
47:46 if you change. If you bring down here, it's gonna change this
47:51 , okay? And, uh, it will also impact. This is
47:56 . So it will. Actually, f is gonna end up at the
47:59 place so you can put you can this whatever you want to, but
48:05 put it south of here. And think too hard North. You're just
48:08 of put it out a little bit s so that you can get a
48:11 triangle in there. Okay? I actually misspoke. It wouldn't be
48:17 because the points A and B on ft apart, necessarily in Matthew.
48:24 , Okay. Okay. So we this. And so what we want
48:34 do is take take our basic, , you know, sort of our
48:41 map that we have to the south overland on top of this. And
48:46 course, I knew where it was to cut off. So when you
48:49 you're actually drawing it, just extend things out a little bit when you
48:53 your contours. And when you put under here, um, here you
48:58 the twenty four hundred one and it's hit at 2400 here, it's gonna
49:03 a 24 100 so you can figure where it actually cuts it. In
49:07 words, this is where the this , where the surface stops, and
49:14 that contour, the surface stops Note. This is a a flat
49:18 child, and but I'm putting a surface on it. So the so
49:23 actual intersection is gonna climb up section this surface, the red, the
49:30 contours, air curved and they're gonna gonna climb up the fault, and
49:35 gonna make the expression of your fault two dimensional two dimensions look, curve
49:40 that. And so here we have a plainer fault, and we have
49:46 curved surface creating a curved intersection. then once you do that, you
49:51 , you you raised this stuff off then then you can put your other
49:56 points in and and do a couple other tricky things. And here's what
50:06 figure kind of figure out what? throw is on the fault, and
50:14 it's gonna be and just kind of it equal distance here because we have
50:18 plane of surface. And so it'll come up like that. Okay?
50:29 in this example, you're gonna you're be able Thio, move the throw
50:34 the fault like this. And I'm to think of what kind of data
50:39 have here to help you with the . I think I give I give
50:45 the throw on the fault, uh and so in a vertical
50:51 that's the throw right there. Here's throw. And so these lines where
50:58 line is, it goes up there it gives you a point on the
51:02 side. Should be exactly what that is on the other side. In
51:05 words, these air new data points will help you map with the contour
51:12 on the wells above it. In words, here, here is um
51:17 climb up here and get the throwing fault climb up here. So the
51:21 on the other side of the fault be that many feet higher. It
51:24 be the throw higher we're going to the heave and the throw is equal
51:28 . Though it might be 45 degrees not. You're gonna come up with
51:33 different than 45 degrees. But if actually did the math and calculated it
51:37 scale we're drawing, you probably wouldn't able to see it. So just
51:40 make it easier pretty much used the on the fault as your as your
51:49 offset here on S O horizontally. be equal to what it is
51:56 so you'll come up like that and hit. It will come up like
52:00 and hit it. That's why there's gap, because this is the surface
52:04 mapping. This is the fault playing the surface doesn't occur. And then
52:11 the surface is on the foot it'll start popping up over here.
52:17 everybody see that? No. And kind of visualized that in their
52:22 In other words, I have surface here, which are these points come
52:29 , the fault Come up the fault the new surface is up here
52:33 and we know that it's moved up an equal amount of the throat.
52:39 , so the throw is how far moved, and if we use a
52:43 degree angle, plus or minus for for the area on the surface,
52:50 , that's going to be the gap when we when we draw this,
52:54 we calculate this intersection, we can where this line goes. And when
53:00 estimate where that line goes, I have data points just north of each
53:05 of the contour lines below it that can use to contour into the upper
53:10 of the the map. In other , you'll have a fault through here
53:20 , and these will have depths to , but that the boundary between the
53:26 on the hanging wall is going to up here above the boundary on the
53:29 wall. Excuse me. I'm getting backwards that this is the the football
53:35 here and the hanging all down And so So what I'm gonna have
53:41 . I'm going to be able with map overlay. I'll be able to
53:45 out where that is. Put the throw in. So I have the
53:50 . But just north of those well perpendicular to the dip just north
53:56 those those wells. I'm gonna have new point that's going to equal the
54:00 line to that. Well, or contour line I had here will be
54:05 it. And so So that gives . Now I know that here it's
54:18 ft in this map 1800 ft in map in 2000 and at math.
54:23 see that? In other words, gonna have data points up here from
54:27 Wells. But now, knowing that has got to be a certain depth
54:32 that part of the fault where the is, I have additional contour lines
54:38 help me draw a better contour line the north of it. And I
54:43 see that there isn't any closure up when I do that. Okay,
54:51 I sepak maps are pretty much the thing in terms of the contours,
54:57 but they don't require closure. But lot of times, you know,
55:03 going to see closure on, and mentioned this before the ice of packing
55:08 isis Cormac being, uh, different but similar. And of
55:16 normally the way we get the you know, we had an exercise
55:20 he came up with a net pay all that sort of thing. And
55:24 I first did this exercise, I a log sort of use. It
55:28 a type log that was the same every well so people could calculate,
55:35 , the reserves. But what I out is, you know, if
55:39 give a log like this that thio 20 students, there's gonna be 20
55:45 nets Forget 20 different nets. It's be harder for me to see where
55:49 making mistakes in your mapping routine. when I grade these, you
55:55 I accept kind of have to figure not just that your numbers air
56:00 but why your numbers air off. , so here's kind of again,
56:08 a map view on a side view help you visualize this and you can
56:12 a sand comes up here like At some point, you have the
56:16 water contact in another point in oil contact. So it's the rest of
56:22 reservoirs what wedged here and in the , all the way up to this
56:27 . It's going to be full, thickness of the sandstone, okay.
56:33 this one actually shows if you have , the gas will be up here
56:36 the top and you could figure that so we'd cut out some of the
56:39 . We're going to assume this is 100% oil in our exercise. And
56:46 here's another one. Ah, just you you've got an oil water contact
56:52 on the outside. It's flattened on top because of a gas cap.
56:56 it's a slightly not perfectly spherical which has a little a dip in
57:03 in the thickness here. Okay, when you're making a nice APAC
57:12 used the sand thickness for the ice map and, uh and but then
57:20 have a container. So on on end, you're gonna have to worry
57:24 the wedge created by the fault and wedge created by the oil.
57:28 Contact in this example is similar uh, similar to your exercise.
57:38 from Tear Pack and Bisky and and can tell you that it's unrealistic because
57:43 not taking into account what happens. , in other words, you're gonna
57:48 a curved surface up here if if surface is curved. That intersection has
57:53 be curved. Eso they've kind of ized it incorrectly, but but I
58:00 to make it simple what you can here is here's where it's full.
58:04 where it's wedged because of the water, the fault, the fault
58:11 with the reservoir. And here it's wedge because of the intersection. Mhm
58:19 a with a horizontal surface. at the lower end of the formation
58:25 the oil, water contact will be the bottom and the fault contact will
58:30 find your end your base. So ice a pack has shown you is
58:36 here is where it's full and here's it's full here, too. And
58:41 if I if I know what where point is and I know where these
58:46 are, I can just equal distance and kind of draw a line like
58:54 to see where the contours will And I could just fill in the
58:58 right there. So I need to need to find this this area,
59:02 I need to find that air the from here to here and actually the
59:08 from here Thio here because that's that's telling me where it's full. And
59:15 from here to here is telling me whole area in between, from this
59:20 to their its contoured that way from line to their its contoured that
59:26 But it all depends on the dip the bed and in your example,
59:30 bed won't be dipped as much. this this area here will be
59:34 It'll be closer to the fault. because it's not, this will be
59:38 out and this will be stretched So that's what's different. Some students
59:43 copy this map, put some depths on what I gave him, and
59:49 they don't even put it to And they call that the volume.
59:52 do that. It has to be on the map that you have.
59:58 , so in overview, you're going make a structure contour map of the
60:04 of the sand and went on the of the sand and you have to
60:08 the top of the sand in the in the sand. So here this
60:13 you draw your oil, water contact going to tell you where that
60:16 Where the fault intersects it on the will tell you where this is.
60:21 you draw your surface against the fault oil water contact, it will give
60:28 what that area is. You get area that area, you can draw
60:31 map without any trouble at all, you need a top in the
60:34 Yes. Okay, to do this real, three dimensions. And one
60:40 a lot of students forget is to , uh, you know, the
60:46 water contact contour has to be. going to be zero, and you
60:51 label it with oh slash W for , water contact. And so that
61:02 what you're gonna get out of Okay, so that's why you need
61:13 . And there's also going to be fault plane and fault plane dip that
61:19 need to come up in the direction the dip. And then after you
61:24 that for the ice pack map, going to calculate the reserves. So
61:28 by step, this is how you're to do it. And I'm gonna
61:36 really looked at this because I changed some of the slides around, but
61:40 gonna double check and put this online you. So tells you which pictures
61:44 look at. But you're going to the fault plane map first. Then
61:48 going to make a preliminary top and of sand map, uh, integrated
61:52 the fault plane map. Both of have to be integrated, as I
61:57 you s so that you can see the cut is. And it's amazing
62:01 well it works when you do it , Focus on the south side of
62:05 fault. First, use this method contouring Those structures make the top structure
62:12 and draw the contours for the southern of the map below the fault you're
62:16 . Be sure to have an oil contact. Contour line identified.
62:22 And then then you do the same the bottom. Step three. Overlay
62:28 flop the fault plane map to see the, uh, contour intervals hit
62:34 the map. And then, something I don't have here. But
62:37 try to get that on there after done that, then go ahead and
62:41 out. Take you three seconds to out the north side of the math
62:49 . Okay, then make your a pack maps. You can look
62:52 slides. I'm pretty sure this is . Slides 41 to 44 for
62:58 And this will help you understand how playing wedge should look. And how
63:02 well water contact should look. And extra tips on slide 61 for
63:08 And then then then from that, will calculate the reserves kind of as
63:13 . You'll calculate the ice APAC areas a 1/10 inch graph paper.
63:22 if nobody can find it, I I could probably scan one and put
63:27 online for you to cut out. then it wouldn't be, um uh
63:33 a vellum. A lot of times get graph paper. That's like a
63:37 . Also, for the class I , um I had some at 10
63:44 1 inch paper that people could and I would just give them pieces
63:48 it. With the way the cove 19 19 things going on, you're
63:54 have Thio e guess we'll have to resourceful. But if anybody confined,
64:00 can put one online on, Maybe could print it out on thin paper
64:04 something like that, or you can up your maps to the to the
64:11 and, uh, on the a pack to 50 ft contours and
64:17 each layer is like a is like layer cake. And, uh and
64:22 you figure out your areas within that . And, uh, from that
64:35 should be able to add the volumes each layer, and then you'll be
64:39 to do multiply the other rock factors sort out what what is actually the
64:49 . And this is what I mean layers. If I look at a
64:52 and yours is going to be sort semi circle shaped and you'll have an
65:01 in here, uh, you like, a little grid area.
65:07 you count the number of grids to out the area on the on the
65:11 , um, grass paper. And don't have a slide for that because
65:17 normally show people this. So what be looking at is, if you
65:22 this, this is the place where sand is full. And from
65:27 Thio here it switched. And so can actually maybe calculate the volume totally
65:35 way. Has one half of your . Then figure out what it is
65:41 the north side, where the fault . And on the south side,
65:44 it is the oil water contact. add those three areas up. In
65:51 words, this area will be taken of. Here. Here, I
65:55 take care of this. And this the wedge. This and this with
65:58 wedge Kind of a way to shortcut . But you're gonna have You're gonna
66:05 a piece of graph paper. six you're gonna have. Can you
66:28 this? But I'm holding up. see what I'm doing? Okay,
66:41 what you're gonna end up doing is squares. And if you have,
66:46 you have most most graph paper will big squares and smaller squares. So
66:55 the Yeah, the big squares air . Um, if you can see
67:04 . I got a big square If that's full, you can count
67:07 whole big square. You don't have count all the little squares.
67:10 you know, if you're fast it's probably not your trouble. Don't
67:13 where you're at, but but this be an area on the map based
67:19 the scale of the map and you're your and your paper being tend to
67:25 inch. Okay. And so you'll be calculating these areas in these
67:33 One way to do it is to each of these separately and create a
67:40 volume in each one of these terms acre feet going to be measuring out
67:47 , um, on the map and acre feet. We'll come in when
67:53 put the thicknesses of these things, each one of these might be 50
67:57 or less, depending on how you it. Now, you may want
68:00 add precision on the corners when you it that way and go like
68:03 But if you look at this, , thinking about trigonometry, there's a
68:08 of shortcuts you can take to make quicker. And I'm gonna let you
68:10 to figure that out on your or you could just count them
68:14 Like I said, in other I would get an area for this
68:18 layer and make a volume out of with the thickness a layer for this
68:23 . This an area for the top this total volume area. For
68:28 the top of this in the total . Okay? And I'm going to
68:38 into that just a little bit more . But then so that there's gonna
68:41 five deliverables. There's gonna be a plan, and you need to have
68:45 striking a dip in a fall plane and you need to show your work
68:50 that. Make a structure contour map the base of the sand structure Contour
68:54 of the top of the sand. I told you to do the top
68:57 , which I think is a good . Make a nice APAC map.
69:02 sure to wedged oil, water contact a fault plane. You know,
69:06 other words, if you don't have oil water contact marked on your
69:11 you're gonna lose a point at and it doesn't mess everything else.
69:15 you're going to calculate the reserves from volumes that you get and and
69:21 this is this is a summary of those deliverables will be. Then the
69:27 reserve estimate is going to be done way, and we're gonna have rather
69:37 worry about stock tank barrel, you , oil shrinkage and whatnot. It's
69:41 to be limited in this area But I'm giving you a recovery
69:45 So you can read this for the , but hence our reserves. They're
69:48 be, Yeah. 7 77 158 of oil per acre. Foot.
69:58 , so you're gonna multiply that number your volume. Which of the rock
70:04 is going to be based on the and the area in acres that you
70:09 times of ferocity as a decimal In other words, if it's 25%
70:14 250.25 it's not 25. Then times oil saturation, which is usually figured
70:21 one minus the saturation of water. other words, if you subtract
70:29 saturate saturation of water from it, give you how much is oil and
70:36 then the recovery factor. So we're of figuring out I'm going to get
70:40 area an acre feet and times the gives me the volume of the rock
70:53 of ferocity times this times that so really yeah. You don't have to
71:05 . This just gets the acre. gets multiplied times the times the
71:11 Let me fix this. I think actually changed this today and the height
71:31 the rock. Okay, so you'll areas. So for each layer you
71:36 have an area in the height which come up with a volume,
71:42 uh and then you can multiply that volumes for each layer layer by the
71:48 , the one minus the situation of , times of recovery factor and come
71:53 with your total volumes. Okay, here's you calculate the ice pack areas
72:05 1/10 inch graph paper, and I hand you a copy of it.
72:12 gonna What I'm gonna do is suppose online for you and measure the area
72:19 50 ft contours. Assume each layers a layer cake. Determine three area
72:25 way. 50 ft thickness to get acre feet. In other words,
72:29 gonna have the area multiplied by the , so each layer you'll have
72:35 And of course, it may not , uh, I think the thickness
72:39 this whole thing is 240 ft. gonna be 40 ft, not 50
72:43 , and yeah, and then this give you the total volume of
72:49 Then you had those volumes together and average prostate for these wells is going
72:55 be 21%. The average water saturation 10%. The recovery factor based on
73:02 fields in the same playas, 34% into account, um, then the
73:08 tank issue the nets sand for all wells, I decided to make it
73:13 the same is 80% and and then really, what's going to impact?
73:19 your results are is how well you your contouring and how will you,
73:24 , connected to the fault plane map that sort of thing? And there's
73:30 closure for the wells on the up own block where the football block eso
73:36 there's no oil up there. Some will actually try to put closure in
73:39 reservoir up there. Okay, And your data set. And when you
73:53 the right, um, type of and I'm gonna put an example where
73:58 small square equals 25 100 square feet this one equals that many square feet
74:06 an acre equals this many square feet you can figure out that an acre
74:11 is 777 107 58 barrels of Okay, When you when you do
74:19 calculations and here's some more stuff to you. And yeah, this is
74:29 to just There's a basement. Use one because print this out, the
74:35 might mess you up. But here the actual scale that you need to
74:39 with. And I gave you a . It's roughly this 1.8 inches.
74:47 if you print something out of the scale, just check this to make
74:50 you've got a close to the right and use that as your base map
74:56 then these air just extra tips on to do it. And then I
74:59 a page on common missed aches. sometimes people might calculate by acre
75:05 But forget the multiply it by but forget to add the feet.
75:10 words. You have a square Acres is, uh, uh,
75:17 dimension squared because acres is an and then feet gives it a
75:23 And so you do that. And that, any questions, uh,
75:29 you right now, you may have if you read through this, but
75:34 through the slide you have now is get going. But I'm gonna send
75:38 , uh, this sort of revised tonight or tomorrow morning and then,
75:46 and then we'll be, uh, be set. And I'll put I'll
75:51 the graph on there. Uh, . Sure. If one of the
75:59 on the on the foot wall, we still use the three wells to
76:03 up with full planet? Like, now, the three of them are
76:08 the hanging war, right. All will be on the hanging wolf.
76:19 if if because the fault plane doesn't , it wouldn't make any difference.
76:24 fault plane is going to cut right all the wells. Even though there's
76:32 offset on your surface. It's not when when you map the surface has
76:37 . There were the fault plane is be. In other words, there's
76:42 one fall playing. So if it above that, yes, you could
76:44 it. You're asking me in another in this example, you don't have
76:49 worry about that, but yes. other words, you have wells like
76:57 . Two wells like this. There's plane that goes through them and and
77:05 the offset where it cuts a certain certain thing is not gonna You
77:09 it's only going to impact the surface between. Okay, but the fault
77:14 is gonna be the same. The fault plane is just gonna be It's
77:18 to be one plane. It's only to really impact. Um, in
77:25 words, um, Mhm. if I have. If I had
77:42 fall cut cut up here and a cut down here, I could well
77:47 up here and down here and maybe here I could still image the plane
77:53 using that Well, data. but but it wouldn't do me any
77:59 . And figuring out where the offset on the surface is in between because
78:03 gonna be, you know, the here, it's cut through the
78:08 that's the point. That's the And there's a plane that goes through
78:12 this and how that affects each one the wells. How much that offset
78:21 . Okay, And and that offset going to impact the layers, but
78:27 the actual fault plane. Okay, I take a layer and slide it
78:32 here, it's not gonna change where fault codes. Do you understand
78:39 Yep. Thank you. Okay, in our in your example, they're
78:45 gonna be down in here. The the fault cuts all be on this
78:55 the, uh they're gonna be south the the fault. Yep.
79:08 Okay with that, no other questions take a break. Let's make it
79:14 minutes and come back here about 2. 30. Okay,
79:53 Now we're on the lecture. 17 methods, three reservoir details.
80:03 So shot other things that we look besides what the volume is, And
80:09 we get started, I'll just Ah, the graph paper method is
80:15 Poor boy, a poor boy plan for measuring areas. And it can
80:23 be really helpful if you're in situations you can't get thio all your technology
80:30 you're allowed in a room without a . It's hard to do now when
80:35 have phones. But you're doing farming or something like that. You
80:39 be in a room and you could up one of their ice APAC maps
80:44 they're trying toe thio, sell you a particular bit of acreage and and
80:50 down pretty quickly and figure out what rial volumes are using this method.
80:58 ? And in fact, I did a number of times. And also
81:05 when you're not a reservoir engineer or type of designated, um, geologist
81:14 a large company, you don't even access to the software that you need
81:19 do it right. And so the you're not certified, so to
81:27 But quite often when I've had to it in a pinch, Ah,
81:33 success rates been, uh, usually the reserves within within, uh,
81:38 or 2% of what they actually find when they're drilling it, but not
81:44 that perfect. But it's usually close that, which is kind of amazing
81:47 you consider how you're going to be this. So anyway, we were
81:52 starting to look more at the envelope and structures. Important vertical closure
82:00 that structure is important strengths of seals important, which we kind of talked
82:05 . And the hydrocarbon column is And and so where the horizontal closures
82:13 important and also food contacts can have impact on on where that reservoir ends
82:25 . Do you think of an area truncated on on a surface, and
82:32 all these things become more and more . All of these other things we've
82:36 talking about are important. You do to worry about stock, tanked
82:42 recovery factors, something that usually developed an area or a play over a
82:47 of time. And, uh, are the rial fluid distributions? A
82:53 of a lot of places where we lots of Prasit E um, there's
82:58 an abrupt oil water contact. Don't to worry about it. But in
83:03 where the permeability and the pore throats smaller, uh, it's not always
83:09 sharp boundary. So that's important. things that we have to worry about
83:13 compartmentalization of the field with multiple faults perhaps face these changes. And and
83:22 in all, we looked at a of these different things. We won't
83:24 time to do reservoir characterization in but when we have the the more
83:29 genius reservoirs with poor qualities in terms porosity and permeability, for sure,
83:36 when we have to start doing a of reservoir equality type stuff.
83:43 so natural measurements of reservoir. works out to be in, you
83:54 , one in 33 million. In words, for every point we
83:59 there's three million other points that were . Even when we have a lot
84:03 , well, data because, you know, if you consider these
84:07 that are large acres, uh, know, one point in a
84:12 it is not really giving us a brushed idea of what's going on down
84:19 . And, uh, and of , uncertainty between wells and seismic control
84:24 be could be pretty large. Of , the seismic data gives us information
84:29 wills and can create volumes and does creates a lot of incredible images.
84:35 even to this day, sometimes there's differences between what we think is in
84:42 reservoir on what we actually get out it. And a lot of this
84:46 to do with the fact that we're measuring things as perfectly as we
84:49 because because to really do it you have to bring the whole the
84:53 rock unit back. And one of reasons for doing your exercise away did
84:57 was that in a real circumstances, a real situation. You don't know
85:03 the variables, and you'll never know the variables. Doesn't matter if you
85:07 the best gamma logs or the best logs or the best density logs.
85:12 still not going to know everything. there's always gonna be risk and
85:17 And there's just ways, um, know, people can cut corners,
85:23 it has to be calculated. It to be well thought out.
85:27 you do too many, uh, too many corners. You can really
85:31 things very wrong. So at any , it's really important to realize,
85:37 , in the really a lot of uncertainty and your example that you're working
85:41 your exercise. I created a reservoir my mind and poked holes into
85:47 So that way I knew exactly, , how big it should be,
85:53 I was able to even evaluate different routines on computers against it. One
85:57 did it for a capstone project, I think I mentioned this before the
86:02 closest mapping routine and in patrol and other. It wasn't called patrol back
86:09 , but three other and particular, popular software products, uh, for
86:19 doing this kind of work. We're equally off usually, uh, at
86:23 25% and up to 50% off in of the way they calculated the
86:30 Okay, so this is out of out of Shepherd's book, and,
86:36 , I think there's something similar and the glue as book. But,
86:44 , there's a lot of a lot different ways you can do this.
86:47 , you know, you have all variables appeared to top that you can
86:56 together and come up with a piece 90 which is your lowest volume case
87:04 a P 10, which is your volume case. And basically, this
87:08 saying that, uh, your lowest is got a high probability of
87:14 P 90 means probability of 90% success here would be p 10, and
87:21 has sort of in the middle there 50 but that you think you could
87:26 in reserves one of the problems that have with all risk methods.
87:32 and I keep trying to figure out way to make it right. I
87:36 there's some ways Thio Thio get around , but almost all risk methods
87:44 really focus on negativity. Um, they don't really take into consideration that
87:52 of the air up here might make p 10 a lot bigger than
87:57 ISS. And and, of you know a good example would be
88:05 chalks in the North Sea. You , the the volume they thought they
88:10 get out of that was zero, it turns out to be lots and
88:14 . So there's something negatively biased about kind of risk analysis. And and
88:22 been looking at these things for 30 , and I still can't figure out
88:27 they don't. I mean, you , you can say you have a
88:29 end case you could say have a end case. That's optimistic, but
88:33 math is always focused on the The math is never focused on anything
88:38 because there's an envelope here that doesn't . And that's one that's better than
88:42 you think. Ah, but once come up with something in here,
88:49 start thinking of how to knock it from here down to there, and
88:54 me, that's just a negative And, uh, this is just
88:59 you different ways to look at Uh, here's a expectation curve versus
89:06 frequency of these things happening over, know, so money, uh,
89:11 tries of different variables and make a story short. When you start out
89:18 exploration in frontier exploration, Um, typically have a broad range. But
89:25 I was just mentioning, this envelope we have in the beginning of possibilities
89:31 p nine and P 10 could be off. It could be,
89:37 you know, even the peen. could be more negative than the P
89:40 actually. But we always have this that it's somewhere in here. Sometimes
89:45 even bigger than there. And you know, I still think there's
89:52 There's a huge possibility that there's this around the world, uh, like
89:59 Eagle Ford and what horizontal drilling did it that were just totally blind to
90:04 because we have this system of coming with a range and beating the heck
90:10 it, beating the heck out of and saying, you know, this
90:13 where I really want to get to my well of make money and,
90:21 , you know, just it I a good example of this is I
90:26 a CO had a a prospect quality that used probability, and they basically
90:34 out Every, uh, prospect of has drilled since we since we merged
90:40 him. That turned out to be . And almost every major discovery that
90:46 ever found in its 100 plus your would have been missed by the Prospect
90:51 team because I would have said it perspective. So there's, you
90:56 I just There's something wrong with That's all I got to say.
91:01 know, it's like when you roll dice, there's only six sides to
91:04 dice, but in reality there could a 12 sided dice out there,
91:10 we just don't know it, and or don't even consider it. So
91:16 , basically, what this diagram shows that through time, though, we
91:21 this piece of 10 and p. . As we know mawr, we
91:25 of reduce the size of the And of course, after you've had
91:29 couple of wells, you know you getting a better controlling what that real
91:33 is. Like I said out here frontier, you may be so far
91:37 you're killing your killing the best prospects . But do you eventually work down
91:43 to where you're not really looking at ? And sometimes I'll look out.
91:47 at these diagrams just to show you asking things about like this is risk
91:55 defined when you're in development? Is more poorly defined when you're in
92:01 And so I'm kind of showing you I don't want to go into statistics
92:06 with you cause that we have to out with what an average is for
92:12 . Okay. And here's here's something showing some examples. Hot field went
92:18 3 to 7. Reservation from 601 thing. Of course, we
92:25 uh, O. B s in , and it went up thio another
92:30 million barrels of oil reserves. So even when you think you've got everything
92:35 down, uh, you're blind to lot of variables. Even with the
92:41 data that you think you have now it's it's it's, you know,
92:47 almost, um, sort of a thing. Humans at any point in
92:52 , I think they have the best and we have all the good
92:55 the good logs, everything. We're going to know what's going on.
92:58 we're still in the dark. And true about life. Not just for
93:04 , today we think we can. can solve all sorts of medical
93:08 and Covad, 19, has showed that we can't. Ah, two
93:14 ago, no one ever thought something this would have happened. It z
93:17 of why we're all caught with our down on this problem. People had
93:22 idea something could be a dramatically as this has been. So that's
93:28 the negative side, as opposed to positive side. But positively, things
93:32 get better. And and, and that's that's kind of why it's
93:38 to look at risk when you're dealing oil exploration because you only have so
93:42 money and you may have a lot prospects. So you do have to
93:46 on the best ones, but you have to have enough insight to
93:51 But sometimes this envelope is too small the start and and the eventual envelope
93:58 going to end up somewhere in this for the hot fields going to end
94:02 probably way outside of that envelope for it was when frontier expiration was going
94:11 . Okay, So, like I , the trap envelope is critical,
94:17 we showed some of these kind of . And, you know, once
94:23 have this trap envelope here, you a fault. And here you have
94:28 oil water contact. And whether it any deeper or not all has to
94:34 with how far this closure is. . This thing, they have,
94:41 , threefold seismic in here. So good to there and they had they
94:47 close your way out to here. suspect because we don't have as good
94:52 information. But I would say you know, with a two D
94:56 here nailing the closure on that line line in that contour line.
95:03 you don't know what's going on over , but that two d line right
95:07 would probably give you as much information three D in terms of what you
95:10 need to know. And same with line over here looking at these
95:17 But, you know, this kind this contour, it was kind of
95:22 , but But, you know, you see a point here and a
95:27 that's moved towards the fault and not from the fault like this over
95:32 you know that it's the contour lines therefore the surface has to be
95:36 So there's a lot of things that can use even when we don't have
95:40 d seismic. Okay, Another Uh, like I said, the
95:46 water contact in nice force impermeable conventional is, uh, pretty straightforward.
95:57 , and it can have an impact on Ah, a lot of other
96:02 , uh, in a regional in terms of how it's being
96:08 But the lower the permeability and the the ferocity and the smaller the pore
96:14 , this transition zone tends to get and s So there's a lot of
96:21 in in the in appraisals we've pointed before and figuring out where,
96:27 where that oil water contact is once get well, data. And,
96:31 , first Well, they had an down to, so they knew it
96:34 full to here, but we needed drill another well to actually find that
96:38 water contact. As we got just little bit past that. We actually
96:43 in oil water contact and could figure that it was actually, um,
96:49 a bigger area than we had before again that's trying to figure out the
96:59 total envelope of that reservoir. Now people have kind of argued with me
97:04 little bit. I don't know if an argument or discussion, but But
97:08 , you know, like this well like way off the center of the
97:14 and he ended up in full of is he could have gotten the same
97:20 drilling right there. And the thing , if well, what? Our
97:25 was just just inside of there. won't even know there's a reservoir
97:29 But if you drill it here, least you know there's a reservoir down
97:32 whatever that full sand would be if drilled it up here. But as
97:38 come down here, I've got If I drill the well,
97:40 it would be full there. It be there. It would be full
97:44 , and it would be full all way down, Do you hear?
97:49 if I get across that line, gonna find an oil water contact.
97:52 . And in this case, they So drill the expiration. Well,
97:59 then drill the appraisal and this is showing you in, Ah, cross
98:09 What this looks like And, uh actually, uh, a lot of
98:14 when we have multiple layers like unless you're producing from one of those
98:20 just by the nature of nature lot of times is Well, what
98:24 will come across here like this? if that hydrocarbon column gets too strong
98:30 will start leaking a little bit in collaborate a little bit and be a
98:35 bit higher because in this in this , um, you know, this
98:41 to go up to reduce that oil if they have the same strength
98:48 And if, for example, you well, on this thing, this
98:56 fortunate, you have oil jab oil this one, and you have gas
99:00 this one and with pressure data, course, you could plot these lines
99:04 figure out where that gas oil contact without having to go in and drill
99:10 well, to figure out where your leg is, all the way across
99:13 reservoir. And of course, you at this and you know that the
99:27 And this is actually kind of looking , um, how things a
99:32 abrade and capillary pressure. There's going be increasing from one to the
99:39 and so as we go from So we're in a heterogeneous rock and
99:47 go from some poor throats like this some four threats like that and some
99:51 threats like that, we're going to up seeing all sorts of different.
99:58 , what are columns across the Water contact. And so you end
100:02 with something that could be considered transition . You know, every everything's got
100:07 down here. Some places might have little bit more water there and a
100:13 bit more water there and a little more there and a little bit.
100:15 , you're gone from a lot of here thio, less water, less
100:22 , less water, and then all oil. That's kind of what that's
100:25 to show you. And this is two different things from two different
100:33 Um, this is out of your , I believe. And this is
100:38 of the shepherd book over here. showing you Ah, here's water saturation
100:45 the way to irreducible saturation if you , uh, what a wet,
100:50 rock you can't get rid of all water. Uh, but what you
100:54 is gonna be nearly 100% oil at point. And what you produce
101:01 down here is going to be 100% below here. Somewhere in here,
101:05 gonna have immobile the mobile oil, , mixed in some kind of wild
101:11 like this. Cap Hillary pressure, . And so you're gonna have some
101:16 stuck down here that you can't get . You're gonna be, uh,
101:20 less and less water, though, more and more oil A Z,
101:23 go as you come up into here the open part of the of the
101:32 . Okay, petroleum fields, a simple, you know, single
101:37 like the reservoir you're gonna be And it often requires a good number
101:43 wells to be fully drained. And course, in unconventional um, the
101:52 and volume immediately around the wellbore is about all you can drain. So
101:58 have to have a lot of So that's a huge difference in terms
102:03 capital outlay up front, front But one of the things about unconventional
102:10 , after a while, it so risk envelope really isn't gonna change much
102:15 each well. But it is. always going to be a balance between
102:22 much capital outlay you gotta put How much of that can be,
102:29 , actually deducted as taxes versus capital can be a huge, uh,
102:36 in terms of figuring out economics of things, too. So it Zraly
102:42 . But also, you can have to completely separate these reservoirs, or
102:46 can have partially sealed barriers and And this is just showing you,
102:55 ah, field in Venezuela That has lot of compartmentalization. And this does
103:02 look unlike the example I showed you from Venezuela by Kathy Farmer. But
103:12 of the things that helps you figure out is looking at the lowest known
103:17 . If it's the same, they're draining the same continuous reservoir. If
103:23 offer they get off, there's a chance of separation you don't know
103:28 So a map like this is usually useful in detecting compartmentalization of. So
103:35 looking at these fluid contacts. You also look at initial pressure and
103:40 Pressure changes across these potential boundaries or . And, uh, then,
103:47 course, the ratios between gas and and water and oil and all that
103:55 of thing can be, um, important. And sometimes the hydrocarbons in
104:02 in the composition and the water composition these boundaries can give you an indication
104:07 whether you're draining the same same continuous year. And this is just
104:16 um, mhm looking at production Another thing people like to do.
104:23 here's the production profiles. 11 a better than this one over here.
104:27 there's so sometimes you don't even have map in here fault. And maybe
104:30 have a 30 ft sand and uh, seismic. Can't tell you
104:34 a break there, but you can't a fault. There's a 40 ft
104:38 fault in here, and it's separating things and eso. Sometimes you can
104:44 these types of things to help figure where you have compartments. Nothing in
104:50 reservoir. Property distribution of geologists likes thing about little faces. Reservoir body
104:57 , reservoir quote, correlation from one to the next, and continuity of
105:03 fluid flow in sort of the internal that affect sort of the pathways of
105:09 best flow. In other words, we would call it heterogeneous. The
105:16 would call it an anti softer, I Satrapi that z affecting flow some
105:23 , but sometimes east and west it better than it does north and
105:27 depending on things that are going on his geologist and for people that had
105:32 photography. You know, there's a of surfaces, uh, they can
105:36 across and and eliminate particular faces. so one of the things that when
105:45 Characterization first started was to look at big geological models. Then, of
105:51 , uh, they look at internal by looking at all these different things
105:56 affect porosity and permeability and try toe a map, map it across the
106:03 , and then there's, you way CIA faces. We know there's
106:09 faces with that so we can project like a floodplain is going to be
106:14 something. If we determine that we an alluvial of channel and stacking
106:21 things could be important. And platforms we see can be very significant.
106:28 this is just kind of showing uh, from trapped definition all the
106:32 down to, uh, what we for reservoir Characterization. You can see
106:38 all sorts of things in here that just in this channel belt the create
106:44 , ease. We're actually looking at like this. This channel has the
106:51 leg preserved. That's all this has than that. This probably has some
106:55 bars in it. Over here, got a clay plug, so flow
107:02 be good in and out of the of this slide, but going
107:06 there's a lot of bed boundaries. there's any segmentation, iron stained cement
107:12 type stuff going on in here, could have forced sorting in here that
107:17 shut down porosity and permeability all sorts things in here and get down all
107:21 way to the microscopic level and maybe the ECM level to see that there's
107:27 lot of heterogeneity whom, when in early days we just would look at
107:33 sand unit like this and just call one ferocity, one permeability all the
107:38 across. So one of things that do, uh, with alluvial sand
107:47 . Um, we drill a we have We have a thickness,
107:53 we don't know what this is. we have seismic, we see these
107:57 belts, and sometimes we call them . But channel belts that we see
108:01 seismic are actually a bunch of interacting that air leaving different bits and pieces
108:08 this one. The basil part of cut into sort of a mid,
108:13 level part of that channel which was into by this channel right here
108:20 So you have a lot going on a channel built. But one of
108:25 critical issues is when I drill a , I have a thickness. But
108:31 I don't know from that well is far does that channel with that thickness
108:37 ? In other words, we look aspect ratios. In other words,
108:41 know what the vertical isn't here. can I predict for the horizontal in
108:46 direction? And there's three different ways could do easily. Three different
108:52 You can do this. Ah, is looking at outcrop data.
108:59 one is looking at empirical equations that developed, um, looking at lots
109:08 lots of things around the world and one, a seismic data. And
109:11 , of course, some of the of things we look at for Cornwell
109:15 so much smaller than this. But end of the day, we're trying
109:18 figure out how to get that. I drill into a well, that's
109:24 certain thickness. How can I figure what is gonna happen with that channel
109:30 racial So again? Well, gives this seismic can give us channel
109:39 It's not going to get this But if this were a channel belt
109:43 not a channel, seismic can help get this. And then, of
109:48 , people go around the world and at many, many, many
109:52 uh, channel systems currently active today try to come up with some empirical
109:58 to come up with an equation to come up with some answers on
110:03 so that if I drill a I have a rough idea of how
110:07 the channel belt can be. And is, uh, these two diagrams
110:13 doing kind of the same thing this is the colored version of a
110:19 figure in your book, the bluest . But this is kind of showing
110:23 that the aspect Rachel ratio between mean and sand body with and these would
110:31 for Alec or near shore sand bodies a barrier island core, which is
110:36 really good thing. Here's but other are Shoreline shelf title. We have
110:42 lot of things your Title Creek distributor for distribute, Terry. And,
110:48 , it doesn't actually have barrier bars here, which is something that should
110:53 like, but they're gonna have barrier . We're gonna have, uh,
111:02 to the coastline. Could be very or very short, depending on the
111:07 ranges at the time of deposition. that may be a difficult thing for
111:12 to figure out is what the title were there. But you can do
111:15 with geological model, but also the and then perpendicular to the beach in
111:22 barrier for is another number that you . It's not on this chart,
111:26 this is showing you how you can something like that. And, uh
111:32 , there's also diagrams like this for faces, which is really important relative
111:38 correlation because it shows that most of shell faces, uh, real thin
111:43 can extend for a very long and thick ones can presumably extend
111:50 And, uh, they can't. you know what I mean? And
111:54 why the shale markers and the shale air really good for correlations. Here's
112:02 so we're kind of like this is is the results of one of those
112:06 . I was taught empirical results, here's, um, going out looking
112:13 outcrops and exhumed units along the Caspian , that air buried offshore in the
112:20 Sea and full of oil. So actually looking at an outcrop of the
112:25 of channels that you should be in , countering in a particular formation
112:30 And in this in this instance, , he's identifying individual channels, but
112:37 got a channel belt that goes from to here, and he has a
112:41 components for the channels and then different for the whole channel belt itself.
112:47 he's figuring all of that out, here's a channel about that's 5 m
112:52 . It's 420 m along, said outcrops that should reflect almost exactly what's
113:01 produced. You can get on idea that aspect ratio. And,
113:10 he did have three d seismic in area, and it was really hard
113:18 keep getting students to work on this they'd all BP would support him,
113:22 then they would go to work for U. S. Company. But
113:26 managed to get quite a few students here. And you can see here
113:30 , ah, well well developed channel cutting into the strata. Its's not
113:37 obvious as you might wanted to Here's another channel belt over here.
113:46 , it might take me a Some of you may. This may
113:48 obvious to some of you, but would take me a while to to
113:52 your eye, to be able to how obvious these things are. But
113:59 , in the seismic, you can channel belt with and a channel belt
114:04 , and so you can kind of an aspect ratio from that too.
114:09 with inputs from seismic data, very outcrop data and data from around the
114:18 , you can kind of come up an estimation of what you expect to
114:23 . And it's also something like Statistically, you can do it from
114:27 . Well, and, uh, see one sand like that, it
114:32 look like this or that one scene that, Um, again, going
114:39 the negative probability approach, you'd end with a bunch of little sand masses
114:44 this through here. In other you're taking the in here is 100%
114:52 , 0% 0%. And here, going to say, Mm hmm.
114:58 a good likelihood that that sand continues . I'll take some of that sin
115:03 put in a stringers above and stringers . Or here I'll decide to just
115:09 constant proportions. And over this I have a certain proportion of
115:15 and I distributed the sand stringers like . And, uh, that's a
115:21 . It's kind of where you go from having one WellPoint to lots of
115:26 cells and reservoir characterization model. So could be overly negative sometimes as
115:34 And anyway, with object modeling, know what these things are shaped
115:38 We figured out what the aspect ratios , and yeah, well, here
115:45 a well here. This is what penetrated. Based on what you
115:49 you kind of project what you think going to be lateral to it.
115:52 then, uh, you'll come in , er well, bodies that kind
115:56 match. The density you have here the density you have there and and
116:03 of this randomness causes problems. So move it over to another place because
116:09 , uh, you know you're gonna all this open area that isn't really
116:14 into account what's happening here? Because stacking to some extent focus is where
116:20 next deposits they're going to because it faster and it starts to create accommodation
116:26 . And so over here, you to assume something like that's going on
116:29 the middle. So you've gone from points to a bit of an idea
116:36 where it might go laterally and then filling in where you don't see the
116:42 and this is really good seismic and it's not that clear cut.
116:51 unfortunately, we didn't have time for student thio plot these, uh,
116:56 scale. But this is 232 5 7 76 m separation between these
117:04 So the spread on these things sometimes a little bit, um, sporadic
117:11 we do the next realization. But it's because, uh, if I'm
117:19 between these two wells, sand bodies cross over, whereas that same sand
117:24 couldn't make it all the way across between that gap or this gap.
117:32 this is kind of how it was originally with Sandy. And it's like
117:42 . And this is what ended up doing using these aspect ratios with several
117:49 sources of input. Riel, seismic of producing sand bodies, uh,
117:58 of a similar formation that are being offshore and physics. Um uh,
118:07 models that people have developed looking at belts around the world in this type
118:12 terrain. So you go from that something that looks like that and
118:21 some of these air cut off cut mawr when you have these big,
118:25 long distances between the wells. If plotted this distance between, uh at
118:33 , you get a better handle on that ISS that we look like and
118:39 our second lecture done, and we'll ahead and take another 10 minute break
118:48 and I'll be back promptly. E will see you guys about. Let's
119:10 make it 3 28
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