| 00:02 | Okay, we're gonna talk about braided and then we're gonna talk about |
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| 00:08 | reservoir properties and fluid systems. Now, yesterday I talked about how |
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| 00:17 | in the lab, we can see as you steepen the gradient of a |
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| 00:24 | straight stream, it actually gives me . Um But then as you continue |
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| 00:31 | increase the gradient, it goes from answer to breathe. And we've seen |
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| 00:36 | in all these DFS, we've seen the proximal portion is steep graded, |
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| 00:44 | down into a finer grain, gently system, this band. So this |
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| 00:51 | to be a pretty good generalization. from that, we talked about how |
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| 00:57 | combination um slope and channel forming discharge can be external variables. Alice, |
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| 01:08 | click variables to control the pattern of formation. And we see this river |
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| 01:16 | going from graded to meandering. Uh if we look at the slope |
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| 01:22 | you can do this. Uh It almost twice the speed where it's raided |
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| 01:31 | worst, there's no tributaries coming So, you know, there's no |
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| 01:37 | in channel discharge. So this transition strictly a function of the change in |
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| 01:44 | . And of course we saw that uh this particular example is the Alpine |
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| 01:51 | D. F. S in but we saw it in South America |
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| 01:58 | Argentina as well. Um And uh and India. So let's let's look |
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| 02:05 | these rated and maybe the single most component of a greater channel is a |
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| 02:19 | channel art. And so um if think about this bar, this sitting |
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| 02:27 | the channel is causing the divergence of flow and convergence and imagine this migrating |
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| 02:33 | street, Well, we can begin see the types of bed forms that |
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| 02:39 | gonna see there. And we're gonna the pattern of migration that we're actually |
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| 02:46 | get at least something analogous to meander . Except they're basically they don't have |
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| 02:54 | same hope to get graphic rhythmic d'amore fick appearance, but they're basically |
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| 03:03 | be flood sets. Okay, so got upper floor plane beds and reduces |
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| 03:12 | is forcing over the top of the . They've got horse grain bed |
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| 03:18 | gravels, dunes in the channels. then as we go, the rest |
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| 03:24 | the the far now we're gonna go ripples and find a great material and |
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| 03:32 | we're also getting oppression not only in bar itself in the downstream portion of |
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| 03:39 | but also laterally. Uh sitting right . So we get lateral accretion to |
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| 03:52 | so this is down street notice though lords and so not only translate, |
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| 04:01 | one channel is beginning to become Um You can never keep two |
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| 04:10 | the same one will always become dominant some point. So you can see |
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| 04:17 | the pattern of channel migration is going vary. And that channel, one |
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| 04:26 | those two channels, if you'll be bed. Um so this channel has |
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| 04:33 | abandoned and this channel now is the channel. And now there's gonna be |
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| 04:37 | school rather another mid champ uh forming here. So in reality we rarely |
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| 04:52 | if the instrumental translation instead, we to have kind of a overlap and |
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| 05:08 | and it in part relates to the dominance of one channel versus the |
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| 05:18 | Okay, so let's look at a section of a system like this. |
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| 05:22 | this system is beginning to fill. is because is beginning big dominant. |
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| 05:30 | here there's one channel bar to the bar this channel is filling up, |
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| 05:38 | bar is still accreting, this channel migrating laterally. Okay, so we |
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| 05:46 | look at this laterally accreting package in reality is kind of obliquely accreting |
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| 05:55 | uh still it's going to give you flood deposit. It really is gonna |
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| 06:03 | a lot like we would have seen a point bar and it could be |
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| 06:08 | pound or simple. Okay, and we actually see that lateral accretion gradually |
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| 06:23 | as the channel is abandoned. This is being abandoned as this channel continues |
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| 06:34 | . In reality, this channel will at some point be filled as the |
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| 06:40 | goes someplace else. So if we at various cross sections. One of |
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| 06:47 | things we see here is the upstream , the downstream portion and we see |
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| 06:58 | accreting bars. Yeah, we got get to the crests and notice |
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| 07:07 | it says cross channel cross bar channel . We're gonna see that often there's |
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| 07:15 | little channel that cuts across here and for a while we actually get some |
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| 07:25 | , appreciate it. Okay, so this channel moves sometimes it creates like |
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| 07:33 | up straight. Other times it's just . And so upstream we have upstream |
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| 07:44 | or erosion in here are some of channel fills and this is that downstream |
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| 08:03 | the channel has filled. So the of accretion is flood deposits that we |
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| 08:12 | about some detail with laterally creating packages point bars is gonna be the same |
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| 08:21 | with the bleakly accreting mid channel bar's let's let's look at general pattern. |
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| 08:29 | is a series of mid channel Uh these are referred to as longitudinal |
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| 08:40 | for obvious reasons and these are transverse . Yes, we're gonna focus mainly |
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| 08:53 | the longitudinal bars for for the time . So, here is a |
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| 08:58 | this is uh rama putra I And if we look at this area |
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| 09:05 | here we see At least two big handlebars. Almost 2.5 filling this area |
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| 09:22 | the channel. Okay, and if look at that, those mitch |
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| 09:31 | we can see that they're subdivided into channels. So the main channel is |
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| 09:45 | first order channel. The bar is completely across. My 2nd order |
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| 10:01 | It's use your imagination that bar or channel rather Is cut by a 3rd |
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| 10:10 | chap. So you can imagine we've something like this. So the bar |
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| 10:28 | migrating downstream but it's also being cut channels. Cross chance. Okay, |
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| 10:40 | the brahmaputra today is a braided what's called the old brahmaputra is the |
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| 10:52 | stream. It turns out the old Was a braided stream in 1843. |
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| 11:11 | what is now the brahmaputra was a , unnamed meandering river. Sometime in |
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| 11:20 | late 1800s channel of ocean occurred beheading old Brown Put. So what we |
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| 11:30 | was a braided stream that has become under fit stream and it's mandarin. |
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| 11:42 | changed here is mainly the discharge slope changed. So whereas in the first |
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| 11:49 | we saw a transition of graded to because of a slope change a |
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| 11:55 | Here we see a transition from graded meandering because of a discharged change is |
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| 12:02 | beheaded. Same thing happened on the . Same thing happened on the |
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| 12:09 | Okay, so that's the two ways you can have a graded to |
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| 12:17 | Andrew transition of the same room. , so let's look at what's happening |
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| 12:30 | we got this channel. I'm this bar. I mean, let's |
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| 12:36 | this one here. And when we the two channels cutting on either side |
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| 12:44 | . So there's a bar up flow is converging from those two channels |
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| 12:50 | is forming a scallop. In it can be several feet meters deep |
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| 12:56 | the at the this too downstream portion that bar where the channels converge and |
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| 13:05 | erosion is gonna cause the deposition, is the core of the next mitch |
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| 13:13 | to begin that is going to cause with flow divergence. We get that |
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| 13:22 | an elongation of the bar almost looks a little mini bar can down. |
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| 13:32 | At some .1 of these two channels gonna become dominant. When that |
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| 13:41 | the bar becomes more elongated and of it still is gonna be eroding on |
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| 13:53 | flanks and they'll be downstream scallop for . So take a look here, |
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| 14:00 | two channels converging erosion on the side where the channels and these little wings |
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| 14:18 | are occurring. Excuse me. And one looks like it's being elongated. |
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| 14:23 | is probably gonna be the dominant Same things occurring here erosion. This |
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| 14:32 | is being elongated. Now this is a meandering river, This is the |
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| 14:39 | river, but as you would I hope there is a complete gradation |
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| 14:47 | braided and meandering and so more or straight stretches of the trinity river tend |
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| 14:52 | have mid channel barks. Now, you look at the brahmaputra with this |
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| 15:02 | mid channel bar, this elongate bar looks like this. If you look |
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| 15:07 | the crest, there are series of or unit bars on top of |
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| 15:14 | If you draw a cross section, see steeply, relatively steeply dipping packages |
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| 15:27 | . Each of those is a flood . We see four sets that are |
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| 15:35 | . So these are reactivation services and four sets are the result of those |
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| 15:42 | or unit bars climbing up the top cascading down the bottom. Okay, |
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| 15:51 | this is a compound bar again and should insert this. But go back |
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| 15:59 | that picture I showed last time of compound bar in the amazon look just |
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| 16:08 | this. Okay, GpR shows how these are and how deep it |
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| 16:18 | And notice how much variation in scour there is. Uh this is on |
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| 16:27 | order of several meters and those are scalar pools. Okay, this is |
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| 16:37 | bar itself kind of a tear dropped . So as this river channel here |
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| 16:47 | dominant, this ceases to fill or ceases to have sand. It's then |
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| 16:56 | off by this and now we're getting , we're seeing how this channel is |
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| 17:07 | to fill. Okay, now, we look at the fishies associated with |
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| 17:18 | big elongate bar, uh it's rather but let me just point out a |
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| 17:28 | general things. We have lateral accretion the flanks, We have downstream oppression |
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| 17:36 | we can actually have upstream accretion as . So these bars can grow both |
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| 17:41 | and downstream. Now they'll eventually begin erode upstream as they migrate downstream. |
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| 17:49 | there's an upstream downstream and lateral species you like. So the bar head |
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| 18:00 | up here, the bar tail is here, mid channel, we're gonna |
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| 18:15 | upstream accretion downstream, I'm sorry. , upstream accretion downstream accretion unit bars |
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| 18:26 | the bar flanks bar margins. These gonna be mainly reactivation surfaces. And |
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| 18:34 | gonna get some very large four sets well as these reactivation surfaces. And |
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| 18:40 | will be some I don't see him , but there'll be some channel uh |
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| 18:46 | that are cutting in here as And so the individual vertical sequence is |
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| 18:52 | quite complicated. Very much different than meandering stream with just lateral aggression. |
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| 19:01 | are dipping to the left to the downstream upstream. Okay, here in |
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| 19:08 | big stream in Argentina, we get same thing. Okay, we've got |
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| 19:14 | radar fishies. Uh we've got a bar and compound bars. We've got |
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| 19:25 | trough cross strata. These are with caps here. Okay, so |
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| 19:34 | we've got some pretty good vertical Now, modern point braided streams and |
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| 19:41 | is one of the things that remind what we think of braided streams as |
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| 19:47 | desert phenomenon. The we think of streams as why. But shell. |
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| 19:56 | , now with the death ratio still pretty big. But when big streams |
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| 20:00 | very have a big wit, they still have a big death. So |
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| 20:05 | can get very large grade bars in braided bar system. And then I |
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| 20:13 | like the little greatest dream that you walk across. Now in this particular |
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| 20:25 | , they did a flume study to what are the controls on on the |
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| 20:31 | and pattern of braid bars and braided . Well, it turns out the |
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| 20:38 | include the steepness and the discharge. knew that, but also the channel |
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| 20:43 | and the channel depth in the ratio area and the morphology that's seen is |
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| 20:52 | bar. And let me just come , the bar width, the bar |
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| 21:02 | , the width to length ratio, the number of bars within a |
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| 21:14 | Now, what that is is the mode and it's a measure of the |
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| 21:20 | to breeding of breeding. And so you have one mid channel bar? |
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| 21:26 | you have to, do you have or four there? Okay, so |
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| 21:33 | starts rather in the flume at Uh And this is for a constant |
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| 21:40 | and discharge. This is just looking the evolution through time we get these |
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| 21:49 | parts and then these pods began to downstream into kind of trans. But |
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| 22:01 | they're more transverse bars here, but to take over our launch tender |
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| 22:15 | And eventually they stabilize as these compound . Okay, so without changing radiant |
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| 22:28 | or discharge, you can see how river god is formed with increased |
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| 22:40 | The bars get more elongate with increased . The bar heights and areas increase |
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| 22:51 | height and areas decreased with river increase the river depth is the main |
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| 23:00 | for how many braid bars there I mean the area and the |
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| 23:06 | how many bars there are lateral is not a surprise of the width of |
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| 23:10 | ratio and the steepness and you don't to remember this, but you ought |
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| 23:15 | remember what the vari variables are to how these rivers can change. And |
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| 23:23 | a good example of that is platte which in its more proximal part coming |
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| 23:29 | the rockies, steeper gradient, coarser , it's braided the whole system until |
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| 23:35 | hits the Missouri, but it's mainly bars around Denver. By the time |
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| 23:41 | get down into Kansas, it's mainly bars. Okay, and so here |
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| 23:50 | have these longitudinal bars, it's pretty . Uh number of bars in this |
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| 24:04 | here, the transverse bars here and looks like these bars here are the |
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| 24:12 | patterns in the flume as eventually grew those. So if we go back |
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| 24:17 | the flume, this may be the situation for some rivers that are fine |
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| 24:31 | , relatively gentle slopes. This may the terminal stable configuration or rivers with |
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| 24:41 | discharge, coarser grained, steeper So we see the downstream portion of |
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| 24:51 | plan. Is that precursor, if like to more elongated dunes in the |
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| 25:01 | . Okay, one of the things see grain size is decreasing downstream, |
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| 25:07 | sorting is getting better. Okay, what we're seeing is that along the |
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| 25:21 | bars are predominantly in the coarser grain . I'm sorry, the legitimate new |
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| 25:28 | , predominantly the corset range section, , in the fire. Great |
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| 25:36 | So here we have a relatively small strength here, we have a |
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| 25:44 | turns out this is a unit bar before we had those terms we called |
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| 25:51 | bar. But notice this part can be at the river height and it |
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| 26:02 | be exposed with dropping stage and there be reworking of the distal portion to |
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| 26:10 | a reactivation surface. And then the stage. Again it reactivates. |
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| 26:20 | we get something similar on these bigger too. We're gonna look at how |
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| 26:28 | migrate and the pattern of cross sections we get. So here's that bigger |
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| 26:36 | with the first order champ, here's cross channel. That will be a |
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| 26:41 | order channel. We're not gonna worry 3rd order here is laterally accreting and |
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| 26:49 | accreting portions. And up in that's the flatbed. That's the plain |
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| 26:55 | . That's the core of the Okay, so we've got the bar |
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| 26:59 | up being covered with upper flow cheap flower if you like, and |
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| 27:08 | both sideways and downstream. Here. , we only we don't see in |
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| 27:14 | section if there's any upstream accretion or it's all rosy. But now look |
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| 27:22 | we see as we draw a cross down this chant. We see lateral |
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| 27:32 | downstream accretion, we see some dunes are coming down and the dunes are |
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| 27:43 | laterally into upper flow regime plane beds they're being cross cut by a second |
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| 27:52 | channel. And down in here these grading into a first order channel. |
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| 28:06 | this would be a 5th order bounding . These flood packets would be 3rd |
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| 28:14 | 4th order bounding surfaces, and we've erosion scours sitting here as well. |
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| 28:25 | here we've got uh some superimposed some channels. And so you can |
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| 28:36 | part of the problem in these braided is that you've got these bars and |
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| 28:43 | that keep switching. And so there's be a lot of amalgamation within the |
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| 28:51 | with because of these multiple orders. again, going down to this |
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| 28:56 | we have the downstream accreting bars here have the cross channel bars, and |
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| 29:02 | this particular example, there's a suggestion upstream accretion. Okay, so here's |
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| 29:08 | field example, um downstream creating the top having dunes or unit bars |
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| 29:23 | on top. Thank you. we've got bars Climbing on top of |
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| 29:33 | another. Okay. And this is same as was described here. This |
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| 29:48 | in 1980. Uh This was 35 later with the example of well, |
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| 29:58 | stream in the outro. And here's laterally creating bars and notice we've got |
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| 30:05 | channels that are, it's moving like , but we've got some bars are |
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| 30:12 | at a higher angle. Okay, here's a kind of more of a |
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| 30:22 | verse bar system. We've got a . These are basically gonna be |
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| 30:30 | We've got unit bars, we've got channel bars, we've got we got |
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| 30:37 | channel, we've got the cross channel 1st and 2nd order, we've got |
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| 30:42 | flats at the top and eventually vegetated as well. So here we have |
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| 30:53 | bar raiding up into the sand flat a mud dream typical of a small |
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| 31:03 | stream with transverse flowers. The san River, Which across on I-10 between |
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| 31:10 | and Columbus is just such a braided . And the pattern that we get |
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| 31:21 | the same thing here with the mud here, a unit bar rating into |
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| 31:30 | with dunes to ripples. Okay, here we have again, a larger |
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| 31:38 | stream with a lot of unit Here's the unit bar with these reactivation |
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| 31:50 | as it migrates downstream. Okay, capped with this case uh ripples in |
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| 32:01 | of these is if you like a plane. In some cases, the |
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| 32:08 | could simply be the flood slow down a while rained a little less. |
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| 32:16 | it kicked up again as the rain . Because remember these bars are going |
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| 32:21 | be a creep as simply or as as does the rain runoff. So |
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| 32:30 | can have floods. That on the last for months, we're gonna have |
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| 32:36 | , flash floods that last for The longer a flood lasts, the |
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| 32:41 | variation is gonna be. We see on the bars as it migrates and |
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| 32:46 | going to see it offshore from the as we get these high professional |
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| 32:55 | blood generated settlement that's going to be complex as is the flood again, |
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| 33:04 | the radar and now we're getting a view of it. This is, |
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| 33:10 | you like, a sand body, it's broken up. It's discontinuous by |
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| 33:19 | breaks. So here is that body . Okay, here's an example of |
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| 33:29 | migrating with the dune. Here's the face, main slip face, this |
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| 33:35 | of a little wing. Remember we these bars like this migrating? Here's |
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| 33:47 | big scour pool. Okay, up top of the bar we get plain |
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| 33:53 | and ripples. Um This is just this lateral migration here, of that |
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| 34:03 | bar. Just another example of a where you have uh a bar that |
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| 34:13 | migrated with downstream migrating dunes. Superimposed forming these compound sets. And then |
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| 34:27 | it grows to the point where or those dudes are gone. And it |
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| 34:37 | as a simple Yeah. So we bar migration raiding into a channel that's |
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| 34:51 | have coarse grained, probably cross cross gravels raids upwards into downstream and laterally |
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| 35:02 | bar deposits, rating up into sand , which may have some unit |
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| 35:12 | but mainly plain bed had rippled and cut by cross channels. So the |
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| 35:21 | itself is basically gonna the vertical accretion . But over here, we're gonna |
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| 35:36 | that channel is beginning to fill with accreting barge filling in the channel |
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| 35:51 | And here we got a channel and cross channel notice this at right angles |
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| 35:57 | the channel flow. And now we've accretion of the sand flat, going |
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| 36:04 | into plane beds and ripples in sand , much rather in this area |
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| 36:13 | This isn't big band, It's an deposit. There's the base of this |
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| 36:20 | system is sitting right here and this uh paleo soil down below, here's |
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| 36:29 | channel system, there's another channel There's another channel system, there's another |
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| 36:42 | and there's one up here. So is a very complicated amalgamated set of |
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| 36:51 | deposits here. We're looking a little , we can see this one channel |
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| 36:56 | , we can see this one channel and we see another channel up |
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| 37:04 | If we look at the base of channel, we actually see a lot |
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| 37:07 | groove casts and flute marks, soul . Uh And then we see |
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| 37:16 | except the interesting thing about this notice how it's not very resistant to |
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| 37:23 | . There's actually a little AL come , that's normally what we think of |
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| 37:29 | clay or mud. The sand is what we would expect it to, |
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| 37:34 | the base of the channel looks muddy in fact it is because what we're |
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| 37:39 | at our mud class that are falling the tall wagon the channel. This |
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| 37:46 | one of the reasons why L log if you look at that kick where |
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| 37:51 | sand is, he may miss the of the channel because what looks like |
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| 37:58 | for maybe a meter or more is just big class and that's what these |
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| 38:03 | and then what we have on top it, this is downstream migrating |
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| 38:11 | Yeah, here again, it shows how thick that channel lag can be |
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| 38:20 | these mud class. So that's a of meters sick. You see it |
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| 38:25 | as well and again, you well that downstream migrating law here, |
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| 38:34 | see that downstream migrating bar and we little bars migrating on top of it |
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| 38:49 | then going into the steep front. , And we can see that very |
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| 39:03 | here as well. Here's the bar or crest as it migrates. |
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| 39:16 | uh as we get up towards the of that bar, we're getting into |
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| 39:21 | sand flat, we're getting upper flow plane beds and an occasional two dimensional |
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| 39:32 | . So here we have downstream migrating across channel bar or cross channel cross |
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| 39:45 | channel kept within this case a pretty sequence of sand flat, Truncated by |
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| 39:56 | next 10. And this is kind a typical packing that we get. |
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| 40:07 | if you took it out of you might think this is wash |
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| 40:14 | both are upper plain view, there'll any dunes in here too, but |
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| 40:19 | is not a beach, its sand here, we've got that downstream migrating |
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| 40:26 | , not much suspended sediment here, at the angular toe. Okay. |
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| 40:34 | not a big surprise because this, is a more or less a desert |
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| 40:39 | . Here's a Similar one. so going back to this here, |
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| 40:46 | have a bar. Now, we're call it. This is a transverse |
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| 40:53 | , but it's we're gonna call it unit bar. Okay, on top |
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| 40:57 | the unit bar are dunes and Um it's got a scour pack |
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| 41:09 | We may actually have a little bit mud here, and it's gonna be |
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| 41:15 | downstream, and it's gonna look something this. Okay, so over |
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| 41:29 | it's kind of the lateral portion of bar doesn't have these dunes on |
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| 41:35 | So it's a simpler package then up . Okay, so what Galloway tried |
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| 41:45 | do was to summarize longitudinal bars and bars. And the problem is, |
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| 41:52 | of all, they tend not to in the same place. So, |
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| 41:55 | is a very an imaginary scenario, let's look at this longitudinal bar and |
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| 42:03 | that channel bass here is or are and laterally accreting bar system grading up |
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| 42:15 | a sand flat. They sort of channel bar, sand flat and actually |
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| 42:21 | sand flat might be pretty, it'll finer grained, but um it might |
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| 42:29 | up here. Um this is probably here, here's your transverse board. |
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| 42:38 | is easier to visualize in the sense it's the channel downstream. Accreting bar |
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| 42:51 | flat. Okay, so the transverse is really the bar model we're most |
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| 43:00 | with and is typical of sandy, shallow braided streams, it's very |
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| 43:09 | These longitudinal bars are typically associated with streams and a much more complicated |
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| 43:20 | This really does not do it Uh, for the complication and |
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| 43:27 | Now, these big ones to Okay. Uh, nonetheless, this |
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| 43:33 | a good model. This if you the time, you could probably do |
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| 43:38 | better job yourself given what's been done The 1980s or so. Okay. |
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| 43:46 | again, this is kind of a uh, channel channel or are sand |
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| 44:04 | , sand flat. Okay, let's look at that channel amalgamation. |
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| 44:15 | talked about earlier. What if the is actually filling the valley? |
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| 44:26 | Excuse me, on the lateral extent the meandering. It could fill the |
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| 44:37 | well, this is actually science but here the lateral extended, the |
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| 44:45 | , it's about the same size as champ. So the entire incised |
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| 44:53 | I mean size valley fill is gonna channel and that's gonna be something kinda |
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| 45:00 | this. But if they're, the mobility, lateral mobility is less and |
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| 45:10 | going to see more and more floodplain and that's what we see in |
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| 45:16 | the trinity. I'm sorry. that's what we see in the |
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| 45:22 | Here's one flip bill, there's another others. The meander belts are not |
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| 45:31 | as wide as the incised valley. , so we get a lot more |
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| 45:38 | . These sands have at least the for being interconnected. These sands much |
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| 45:43 | . So. Okay, so, you skip this? Uh, there |
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| 45:50 | a discussion about whether or not this a, this is a pro grading |
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| 45:55 | here. And so the discussion is this a distributor very channel. |
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| 46:02 | that was the first initial interpretation. now interpreted as an amalgamated channel fill |
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| 46:12 | belly fill. Okay, well, do you know? Well, mainly |
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| 46:18 | first of all, by looking for basil scours, those fifth order |
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| 46:25 | but also by reconstructing the channel With this channel was relatively small. |
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| 46:37 | , Maximum depth nine m. The was 30 m and so as a |
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| 46:49 | , this had to be the vertical notice. So the valley is pretty |
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| 46:55 | filled by the sand. So it's or less like this, not the |
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| 47:07 | . I mentioned this last time. gonna mention it again because I want |
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| 47:11 | to imagine this is a valley filled here the valley is sufficiently narrow that |
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| 47:24 | point bar is confined to the valley and as a result we have downstream |
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| 47:37 | . So the pattern of channel migration being forced downstream because it can't |
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| 47:47 | But by the time it gets up here it can expand my expansion, |
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| 47:58 | can migrate laterally by expansion. So get a very different style and geometry |
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| 48:05 | the base. In addition, once get out of the incised channel and |
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| 48:12 | began to flood the coastal plain, we can have channel of Walsh which |
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| 48:22 | extend 100 kilometers upstream depending on where apex might be. So we see |
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| 48:31 | these amalgamated channels can then grade up these isolated meandering channels and floodplain |
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| 48:44 | And we can fit that into some of a sequence strata, graphic sequence |
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| 48:49 | sequence of strata, graphic pattern. , So, again, the implication |
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| 48:57 | is that we're still within that zone you static changes affecting the river as |
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| 49:06 | go upstream. Well, actually, is still downstream. Um if you |
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| 49:12 | at multiple valley fields, they're And so the pattern of this, |
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| 49:21 | multiple channels, we're kind of closer where they're spreading out uh is gonna |
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| 49:30 | like the apex of the coast where beginning to be superimposed on one |
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| 49:36 | Then when it spreads out, they're to be more isolated. Okay, |
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| 49:43 | Okay, so, let me end the issue of the heterogeneity of these |
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| 49:51 | real deposits and how it affects their properties. And it ranges from large |
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| 49:58 | channel flu real bodies, meander belts to bar creation and stories to small |
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| 50:10 | individual flood events. So, here's the first publication to look at the |
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| 50:19 | of heterogeneity. And these numbers now not meant to be um the |
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| 50:32 | what am I trying to say? me out um bounding surfaces. The |
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| 50:36 | of bounding surfaces, but rather just of a level of So, we |
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| 50:41 | this huge meander belt and we can of it here. It's done experimentally |
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| 50:50 | , we see it in the And now let's look at a portion |
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| 50:55 | it where we're looking at a man meandering deposits. These are individual |
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| 51:08 | So we've got eight point bar channel Bill White bar channel fill. |
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| 51:26 | if we take one of those point right here, good. Here's that |
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| 51:32 | bar. And here are some of variations of things that might be on |
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| 51:38 | . These are unit bars. And as that creates laterally, it's going |
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| 51:50 | have a geometry sequence of sedimentary structures by now you should be able to |
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| 51:58 | . And so here's that meander belt fill. Let's just look at one |
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| 52:05 | these single deposits right here, chan , third or fourth, here's the |
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| 52:20 | deposit. So think of this It's a transverse sand wave. We |
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| 52:28 | use those terms anymore. Uh, it's basically a flood deposit. And |
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| 52:35 | if we look within here, we're at individual nominations, we're looking at |
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| 52:46 | flow, rainfall translate. So we're into finer and finer detail. And |
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| 52:56 | is analogous to what we talked about when we went from this case six |
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| 53:05 | 7th order bounding surfaces down to And it's what we talked about here |
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| 53:13 | we talked about channel bars or rather channel bar systems. The individual channel |
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| 53:22 | creating packages to individual blood events. , let's think about how this might |
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| 53:32 | a well or a field rather you an injection. Well here, you |
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| 53:38 | is supposed to be producing, it's not gonna work because you've got |
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| 53:44 | too much plugs. Now, you argue that's a pretty obvious one. |
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| 53:52 | knowing where those channel plugs are, that It wasn't that easy in the |
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| 53:58 | when we didn't have this sequence seismic to deal with. Okay, so |
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| 54:03 | is the unspent component. So we need to know the morphology and geometry |
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| 54:12 | all of these channel fills. And these are just some ways of trying |
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| 54:20 | predict extrapolate lateral extent of some of different elements based on vertical extent. |
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| 54:31 | , here's a nice example of a migrating strength and this is a cartoon |
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| 54:43 | , the laterally migrating stream, We've levies abandoned, channel fill. We've |
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| 54:54 | laterally accreting point bar deposits. We've clay drapes up here at the top |
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| 55:05 | this channel has been abandoned and So it's actually two stories. But |
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| 55:12 | been no vertical accretion. So here's second phase of channel migration. |
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| 55:20 | individual pulses of accretion being separated by clays. And then of course, |
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| 55:31 | clay in the dream itself. And using clay in a very general |
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| 55:35 | nonresident. So purple is nonresident So you try to produce here. |
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| 55:42 | is all your in a producer. . In fact, if you look |
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| 55:47 | the head of the deity, we even look at microscopic heterogeneity to within |
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| 55:56 | . We could think about 1st, and 3rd order header, giddy translating |
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| 56:03 | , finding upward sequences, grain etcetera. And here's an actual field |
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| 56:09 | china where in order to to really this, to get every drop of |
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| 56:19 | out of here, uh they ended putting 100 wells per square clone. |
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| 56:25 | mean, it looked like a but it allowed them to figure out |
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| 56:30 | detail the flow geometries. And so got these mud drapes, we've got |
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| 56:38 | channel fill, we've got flood plains as we had drapes, abandoned channel |
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| 56:48 | and floodlights. So, if you to produce from this kind of flu |
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| 56:56 | reservoir, uh to get as much as you can, uh you're gonna |
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| 57:02 | to know this type of detail. This is just the uh in the |
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| 57:13 | of coverage that they have in order uh develop that field, it will |
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| 57:21 | this. This says the same Uh this just goes into some of |
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| 57:28 | seismic uh characters of this and this the seismic Gilmore with strata trace. |
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| 57:41 | , uh and notice, notice how meander belt are getting separated and they're |
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| 57:53 | here. That's what we have So this is a channel that is |
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| 58:01 | pulsing, but it's a vaulting at spot right here. Now, if |
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| 58:11 | want to model a point bar, do it this way. Don't basically |
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| 58:17 | , shale, because if you you're gonna miss the subtleties of what |
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| 58:21 | should model it like this. So is a laterally accreting bar, If |
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| 58:27 | were homogeneous, this is the kind sweep, you would get 90 Efficiency |
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| 58:32 | 32 days. This is what you get if you modeled it, Recognizing |
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| 58:41 | energy needed. E 46% efficiency in days. Because what happens is it |
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| 58:49 | down here. That's it. You to press for what what? |
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| 58:58 | so there's a huge difference in terms how you develop a point bar, |
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| 59:05 | on how you model it, skip . Um, I'm gonna skip |
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| 59:09 | This is this is basically back when only had the logs, but |
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| 59:14 | it was with the purpose of trying define those packets. A point bar |
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| 59:20 | separated by channel films. Okay, we've got something like this. This |
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| 59:29 | a Mcmoran formation, it's the heavy uh, in uh Alberta is part |
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| 59:41 | a big continental scale drainage system and into uh precursor the arctic. It |
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| 59:52 | well have had s during um components it or title components was within the |
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| 60:01 | region, huge Channels 30m deep. , 10 degree. Dibs point barred |
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| 60:15 | migrating 4 - eight km. So had raided lancastrian raided in coastal in |
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| 60:25 | estuarine point bars and what we get very heterogeneous film. Remember that fragmented |
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| 60:36 | that we talked about? It's not give you a nice uniform dip |
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| 60:47 | Here's more of that lateral fill and here some of the point bars are |
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| 60:58 | what that tells me is there if you like reactivation services in those |
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| 61:05 | deposits and you can see it in period. So this is their |
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| 61:14 | You can look at it, notice the clay drapes. So how |
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| 61:22 | you develop this where you're not going treat it as a homogeneous same |
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| 61:27 | In fact, there's a lot of in here. Then we get to |
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| 61:31 | channel margin and so these are various showing horizontal changes in permeability, |
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| 61:40 | saturation, ferocity, etcetera. the way they're developing these is they're |
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| 61:47 | using um steam assisted gravity granted. as they look at one of these |
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| 61:55 | bars to say in here, they're put horizontal pipes down here, they're |
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| 62:09 | inject steam and that's basically going to up the, I'm sorry, they're |
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| 62:17 | inject steam down here and that's going this team comes in and in particularly |
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| 62:24 | oil sands that are up in uh, they basically melt and they |
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| 62:28 | out the production well here. so injection, I'm sorry, injection |
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| 62:38 | production down here and this goes back where I talked about the downstream |
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| 62:47 | Look at the downstream change in grain . Okay, you really need to |
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| 62:55 | what the plan view is in order know where to put your injections as |
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| 63:01 | . So here is the plan view the lateral changes in rain size. |
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| 63:12 | here is where you end up putting injection well, last case study promise |
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| 63:20 | can eat um, in the java meandering stream deposits and you can actually |
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| 63:28 | the individual meander belts, meander scars , and there are multiple levels. |
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| 63:37 | this typical, this is just one . That's one story of a meandering |
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| 63:44 | . And so we've got, we recognize Kind of three packages of point |
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| 63:51 | deposits in this story. Now, look at a case here where we |
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| 63:57 | like to put an injection well here we want to produce it here. |
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| 64:06 | , the trick is that this was laterally migrating point bar. Okay, |
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| 64:19 | here are our production wealth. unbeknownst this production well, was in |
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| 64:34 | different layer than the injection. mhm. And so it turns out |
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| 64:45 | this produced quickly took a lot longer before this produced because they're not connected |
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| 64:54 | hit. So what we really want do is we want to find the |
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| 65:04 | of the seals. In the case here, the areas of seals are |
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| 65:11 | ones who talked about meandering streams. here alive is not the last one |
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| 65:17 | got graded streams with clay grapes as and they can be basically floodplains, |
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| 65:28 | can be channeled fill or they can flood drapes just like we saw |
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| 65:35 | And so here are just some of examples here's a bar channel fill |
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| 65:45 | And this is the map big of seals, what you're beginning to see |
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| 66:01 | where the bars and the channels So a cross section here might look |
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| 66:07 | like this. In fact, that's it does. And so we've got |
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| 66:16 | crossbars here, sheep pills. Whole level uh types of baffles. |
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| 66:32 | . And so I'd like you to thinking about how this cross section and |
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| 66:38 | heterogeneity of this and this associated Um how it would compare with one |
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| 66:47 | the meandering stream. And just for example, here is one of those |
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| 66:54 | units, big uh longitudinal bars. here are some of the models that |
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| 67:02 | have to do to get a permeability taking into account the various facilities that |
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| 67:10 | have. Okay, that's it. go eat. Um It is 12 |
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| 67:19 | . Uh Let's come back no later 1 45 if you get back at |
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| 67:23 | 30 that's good. Uh Do what can Okay, stop |
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