| 00:04 | And that's the next exercise. This just this one single page. |
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| 00:09 | Oh, there's more over here. . People online have it. |
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| 00:51 | great. Thank you. Yeah. . And and ok, thank you |
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| 04:59 | should only take a couple of Oh, you're doing it. |
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| 05:11 | a few days. Ok. So . Yeah, so yeah, I |
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| 08:16 | right. Thank you. Hm, . Pretty good to me and thank |
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| 09:37 | . So I canceled it was to I just don't feel good enough. |
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| 10:09 | . Just kind of. Alright. . Mhm. Ok. Yeah. |
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| 18:58 | not um that's fine. Top and down. Is that what? |
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| 20:00 | Um What? Right. Oh except for right now I need to |
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| 20:23 | use the restroom too much coffee. , take this off. It is |
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| 20:50 | . Oh yeah. Right. We to get started. Thank you. |
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| 21:31 | there are there are two ways you saturations, two main ways you get |
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| 21:36 | in a reservoir. Maybe you're familiar these or not, but the two |
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| 21:40 | ones are resistivity modeling Archie equation and the other is saturation height modeling back |
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| 21:48 | use cap pressure curves and build a pressure model. OK. So first |
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| 21:54 | , we're gonna talk about one because will help us understand resistivity modeling is |
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| 22:01 | hide modeling like the bullet says, . There are three factors. There's |
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| 22:08 | space geometry. We've already mentioned this throats, uh physical and the chemical |
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| 22:14 | of the pore walls and the physical chem chemical properties of the fluids. |
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| 22:21 | works for initial saturations. It does work for basically after inhibition. Uh |
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| 22:28 | again, the hysteresis, it gets complicated. So we are just gonna |
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| 22:32 | about on the what's called the drainage , which I'll explain in more |
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| 22:37 | We are gonna worry in detail about throats. That's what we're gonna |
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| 22:41 | That's what controls the entry pressure of pores in the cap curve. Uh |
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| 22:46 | ability is the physical and chemical Basically how attracted are the fluids for |
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| 22:52 | pore walls. So you start out we're gonna do water, wet |
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| 22:59 | And so uh the rock actually likes attracted to the water more than the |
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| 23:06 | . So there is, you need positive pressure, you have to expend |
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| 23:11 | to get the oil into the OK. And uh this thing goes |
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| 23:17 | , I'll, I'll show you where is, but it's actually o you're |
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| 23:21 | what's called the adhesion tension or the , right? Because uh actually the |
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| 23:27 | adheres to the surface, you have displace that water with oil and so |
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| 23:33 | ability and capillarity is what we're gonna about go on. And then we |
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| 23:41 | talked about mercury versus oil. The surface tension right is much higher. |
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| 23:47 | it's the relative attraction for the fluid itself versus the attraction for the other |
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| 23:53 | . OK. That determines the inter tension. There's the introduction for some |
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| 24:02 | just like we spent most of uh and this morning talking about vocabulary, |
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| 24:08 | need some vocabulary related to this wet . Uh water wet first definition, |
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| 24:14 | have means and you should circle put exclamation points around only if it's |
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| 24:22 | wet, it means it imbibes only simultaneously, right? An example of |
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| 24:29 | would be like a sponge, If you have a sponge, it |
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| 24:34 | imbibe water. So it actually the is attracted to the sponge or paper |
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| 24:39 | is another good one, right? all judge our paper towels based on |
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| 24:42 | much water and how quickly they will water into them, right? So |
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| 24:49 | got that. They've underlined, circled common way to lose points, oil |
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| 24:55 | . So 100% oil wet means that oil is attracted to the surface water |
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| 25:02 | not. So if you have a that is 100% oil wet, it |
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| 25:08 | imbibe only oil. I have never seen a rock, a natural rock |
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| 25:14 | fits that description. You can make artificially so you can treat them with |
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| 25:21 | basically uh a variety of chemicals, can coat all the quarts that then |
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| 25:28 | be only oil wet. But I tell you, you get really odd |
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| 25:31 | when you do that. Uh, example, the A GN value is |
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| 25:35 | like seven as opposed to typical It's more like two or even less |
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| 25:42 | get as low as 1.6. So ridiculous. That's because the oil immediately |
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| 25:46 | sucked into all the pore throats and off all the resistivity. Right. |
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| 25:51 | so uh you, you don't see oil wet rock. I have not |
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| 25:55 | it, but you do end up wet is also not very common. |
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| 25:59 | imbibes nothing. It doesn't vibe oil imide water. There's one example, |
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| 26:05 | really know Teflon does this, it's oil oil, it isn't attracted to |
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| 26:10 | , it isn't attracted to water. . So, but you don't find |
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| 26:15 | Teflon reservoirs actually, it was invented accident even. All right. So |
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| 26:21 | know it neutrally wet. We'll see how you measure this in a |
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| 26:26 | right? How you measure the wet ? And then this is the one |
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| 26:29 | get more confused about is mixed wet fractionally wet. So mixed wet means |
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| 26:36 | a portion of the grain surface is wet. A portion of the grain |
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| 26:41 | is water wet. And how does occur? It's basically the crude oil |
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| 26:47 | actually alter the wet ability from initially water wet, which is a very |
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| 26:51 | assumption for rocks in the subsurface they formed pretty much in the presence of |
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| 26:59 | . Yeah. And so they start water wet, then what can happen |
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| 27:03 | make them mixed wet is you actually actually saturate them with some amount of |
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| 27:09 | . And if you get a high oil saturation with the right properties, |
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| 27:14 | the heavy ends, the long hydrocarbon , you can alter that wet |
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| 27:20 | Basically. What happens is those long chains can actually extend through a thin |
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| 27:27 | film that you would get at high saturations. And then you could alter |
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| 27:32 | wet ability on that portion of the . That's why a portion of the |
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| 27:37 | is oil wet. A portion of grain is water wet. So this |
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| 27:41 | a lot like why do you wax car? Why do you wax your |
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| 27:47 | ? Anybody do that anymore to alter wet ability? So your car, |
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| 27:56 | what you're saying. So what you, you actually you put a |
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| 28:01 | of wax on it. It is oil wet, right? As opposed |
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| 28:06 | water wet. So the water beads and runs off, right? Uh |
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| 28:12 | . Yeah. So often I give example on Titan it rains methane. |
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| 28:18 | you wax your car there? you would want to make your car |
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| 28:23 | wet there, right? So is clear? So literally, you are |
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| 28:27 | the kind of the comparable thing to a car? That's what happens and |
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| 28:31 | why only a portion of the grain different wet ability gets altered to oil |
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| 28:37 | as opposed to water wet. So model is about mainly about hydrocarbon uh |
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| 28:45 | the crude oil properties. And I when in in the Gulf of |
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| 28:50 | when we looked to predict wet the first thing we looked at was |
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| 28:56 | crude oil properties. How many heavy were present in it? Because because |
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| 29:01 | more heavy ends that were present, more likely you were to get a |
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| 29:05 | , a mixed wet situation. Is clear for everybody? What mixed it |
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| 29:10 | ? Do I need to draw a ? So I have to ask for |
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| 29:13 | to get up out of my Now, if I need to |
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| 29:18 | if I need to draw you a , we can, that's supposed to |
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| 29:23 | wet. I didn't make up this . It's not my fault. What |
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| 29:29 | wet means is it's mineralogy based, wet ability. And a common |
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| 29:35 | people would argue that feldspars may be wet, courts may be water |
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| 29:41 | probably not true, but I've seen argument made or Professor Hathen may agree |
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| 29:48 | this. More clays may be oil versus quartz may be water wet. |
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| 29:54 | it's mineralogy based. OK. So it's all about kind of mineralogy, |
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| 30:00 | cetera. This uh leads to very predictions for what will happen versus a |
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| 30:08 | wet versus mixed wet condition. So example, in an unconventional, you |
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| 30:14 | have intuition. Do you think an would be mixed wet or fractionally |
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| 30:26 | So, by that, he means shale reservoir. Yeah. Shale |
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| 30:32 | Would it depend on mythology or would depend on migrating oil into a high |
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| 30:38 | , altering the wet ability? everybody's first guess is that it would |
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| 30:46 | fractionally wet, right. That it depend on mineralogy, et cetera. |
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| 30:51 | that really true? We have some that would suggest it's not, we |
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| 30:58 | could in our ramen microscope, we watch and we could see that even |
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| 31:03 | the quartz grains, it looked oil . And one hypothesis was that was |
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| 31:11 | to the oil moving out and altering as it migrated out of of, |
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| 31:17 | that uh source rock. So that's a bit under contention. I would |
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| 31:23 | but you, you get very different , right? Yeah, I'm |
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| 31:29 | speak up. Would, would you a shale reservoir to be mixed wet |
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| 31:37 | fractionally wet? So, mixed wet the usual model. People use mixed |
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| 31:46 | in conventional rocks for sure. It's the usual model people use. So |
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| 31:50 | about it starts out water wet uh then can get altered depending on crude |
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| 31:56 | properties. So if you have a light crude, quite likely it's gonna |
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| 32:02 | up water wet, you don't have hydrocarbon molecules present to alter the wet |
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| 32:09 | . So when people do laboratory which I can tell you quite a |
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| 32:12 | is done they'll start with a water rock and they'll put some refined oil |
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| 32:17 | soul troll or something in it. doing water wet experiments, whether they |
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| 32:24 | stated or not. And I know lot of work came out of shell |
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| 32:27 | like that where they actually would saturate a very light artificial oil, |
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| 32:36 | So you can have some insights, clear, mixed wet versus fractionally wet |
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| 32:42 | neurally wet, water, wet or wet. So we have the nomenclature |
|
| 32:48 | great and it yeah, obviously could over time. That was what I |
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| 32:54 | talking about. So how do we it? We ability uh you're just |
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| 33:00 | about this this morning, right? uh cecil drops. So you actually |
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| 33:06 | put a drop on a surface. is actually pretty complicated and then you |
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| 33:11 | at the shape of the droplet on surface, I guess it's called a |
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| 33:17 | drop experiment. And so what you is you measure, you measure the |
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| 33:22 | what's called the contact angle, which this data. OK. And so |
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| 33:27 | this theta greater than 90 degrees means it's non wetting. Remember the mercury |
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| 33:34 | about makes little round balls and rolls . Mercury does not wet much of |
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| 33:40 | , right? It really likes itself than almost anything else. So the |
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| 33:45 | tension is quite high and its contact is uh actually uh is quite |
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| 33:54 | right? This case, right? we have, right? A wedding |
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| 34:00 | , the contact angle is less than degrees, right. And so |
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| 34:05 | you can see it's really adhering to surface, the drop gets pulled |
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| 34:10 | Yeah. So this force is laying the surface, the surface wants to |
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| 34:14 | it out, right. And so contact angle would be quite small. |
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| 34:20 | means it's wetting that surface. Everybody this, what the contact angle is |
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| 34:27 | what it means, how it's you measure it through the fluid of |
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| 34:33 | . So in this case, you're , you're measuring it through this or |
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| 34:37 | fluid. Yeah, you're, you're measuring it through this surface. So |
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| 34:43 | I want the, if I want wedding condition of this gray fluid, |
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| 34:48 | ? Again, non wedding wedding, would neutrally wedding look like? What |
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| 34:56 | the angle would be I need So it would be equally attracted to |
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| 35:05 | and the fluid surrounding it. This angle. Also there's a competition between |
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| 35:12 | fluid out here and the fluid interior the drop. So when you talk |
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| 35:18 | a contact angle, you always have specify all three, you have to |
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| 35:23 | the surface, quartz belts, clay, whatever you have to specify |
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| 35:28 | the liquid is, oil, for . Uh and then what the third |
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| 35:33 | is, air, water, et , whatever it is. That |
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| 35:37 | it is determined by all three So what what this means is that |
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| 35:44 | that this fluid is preferentially wetting over fluid. The fluid out here. |
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| 35:50 | this one, this fluid is preferentially over this fluid. So that's what |
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| 35:56 | contact angle means. We all OK that. So what it all, |
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| 36:05 | , what it's about is the attractive between the surface and the fluid. |
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| 36:10 | those forces are strong, it wants spread the fluid out. If they're |
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| 36:15 | , it wants to take the other and right minimize, maximize the kind |
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| 36:20 | amount of fluid and this fluid that's contact with the surface over this |
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| 36:24 | Yeah, it's kind of important The the the answer is you need |
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| 36:36 | , to tell me what three right? Because it's always the competition |
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| 36:41 | the fluids, the two fluids for surface. So you, you always |
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| 36:47 | all three when, when, when talk about what that wedding angle |
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| 36:59 | fluid is bonded to the source. it's, it's about relative attractions for |
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| 37:05 | surface to the two fluids involved. I'm gonna show you some slides that |
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| 37:11 | clarify this in a minute. If change either the surface or the |
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| 37:16 | you will change the contact angle and will change which one is preferentially |
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| 37:22 | So if you think about when you your car, right and then it |
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| 37:26 | and the water just is in little on your um on your car and |
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| 37:31 | just roll off. That would be you've altered the wet ability by waxing |
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| 37:36 | surface of your car if you don't the surface of your car, the |
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| 37:40 | just spreads out and wax the So, yes, there is |
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| 37:44 | a, an attraction between the surface the plume. So the two fluids |
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| 37:50 | the same, you've altered, you've the surface. We, we're talking |
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| 37:54 | the two same fluids, but you alter the wet ability, whether it |
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| 37:58 | preferentially oil, wet or water Again. If you put a little |
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| 38:04 | of oil on a wax car, oil, it's gonna spread out, |
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| 38:09 | ? And form of film. This like a big deal. If we |
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| 38:15 | get this, the rest of us gonna get pretty hard. We don't |
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| 38:18 | this concept down. Yeah. And reservoirs, I already answered this |
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| 38:27 | Sorry, spoiled all the fun. , what, what do you think |
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| 38:31 | wet ability would typically be? What the most natural assumption to make for |
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| 38:36 | wet ability of a formation when its originally migrates in? That's called the |
|
| 38:44 | phase? I already answered this like minutes ago. Remember when I said |
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| 38:57 | they're formed in the presence of there's no originally no oil present. |
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| 39:02 | what would the wedding properties be? would tend to guess water wet, |
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| 39:09 | ? It's never contacted oil. You make this transition essentially, you can't |
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| 39:15 | the car without any crude oil. quartz is water wet initially. Why |
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| 39:25 | it water wet? Because water is polar molecule. You have truncated crystal |
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| 39:31 | at every grain that means there's exposed charges. And so you get a |
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| 39:36 | attraction and you get an attraction between and quartz. So quartz naturally would |
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| 39:42 | to be water wet. Well, doesn't really care, doesn't have a |
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| 39:46 | , but it will be initially water . You have to coat it and |
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| 39:51 | that surface to alter the wet ability quartz away from water wet. So |
|
| 39:59 | the next question is how about when produce after we produce? So for |
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| 40:05 | , when we're thinking about performing a flood, what assumption do we |
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| 40:10 | Can we still assume that it's water ? My head is a clue. |
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| 40:18 | , why not? Yeah, because have exposed it to crude oil and |
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| 40:25 | on the saturations, crude oil we may well have modified the wedding |
|
| 40:31 | . OK? That's different from the , that's fractionally wet. That's different |
|
| 40:38 | the mixed wet one where it, totally mineralogy. You wouldn't care about |
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| 40:43 | crude oil again, that almost everybody everybody uses that first criteria. So |
|
| 40:51 | is the drainage phase. What does mean? It means you were pushing |
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| 40:55 | the wedding phase. So again, water wants to be there, the |
|
| 40:59 | is attracted to the surface, you to overcome that that requires energy requires |
|
| 41:07 | . That force is provided by the pressure, which is the difference in |
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| 41:13 | pressure between the water phase and the phase, which phase is gonna |
|
| 41:19 | the higher pressure has to have the pressure in a water wet rock would |
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| 41:33 | the oil because the oil has to energy to get, to increase its |
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| 41:40 | , to get it through the poor and displace the water, which really |
|
| 41:45 | like to be there. Yeah, all OK with this slide, another |
|
| 41:53 | slide, it's not a slide, actually power point. Well, |
|
| 42:09 | so we can go back to the slide here. So mixed wet. |
|
| 42:19 | was the model we were using as mixed wet model. Should I draw |
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| 42:24 | picture or not? Would that I'm pretty right brained myself. So |
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| 42:32 | help me. Actually, I might able to do it on screen. |
|
| 42:41 | very good drawing pictures if I had pen lost my cursor. So you |
|
| 43:01 | , I'll do my best. Here's grain, here's the grain, there's |
|
| 43:09 | grain, remember my famous rock, a grain. So we put oil |
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| 43:16 | here, right? So initially, can probably change colors, right? |
|
| 43:24 | What do you want to make? with colors? Oil, yellow? |
|
| 43:34 | I initially remember I put a little of oil in here. I got |
|
| 43:38 | stop clicking that we, we get drop of oil here in the |
|
| 43:42 | right? Yeah. And so is are we going to have modified the |
|
| 43:47 | at this point? No, we a lot of water wave thicker films |
|
| 43:52 | the grains than the length of a . I put a little more oil |
|
| 43:57 | the pore, it's gonna look something this. I'm doing pretty good with |
|
| 44:04 | . Right. So I'm getting actually , I have a fairly thin film |
|
| 44:07 | here's a little thicker, a little . So at this point, I |
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| 44:11 | be getting my oil close enough that molecules, the long chain hydrocarbons in |
|
| 44:17 | oil molecule could interact with that And so I might at this |
|
| 44:23 | this might be oil wet, that . Yeah. However, these would |
|
| 44:31 | , these here would still remain. other two surfaces would remain water wet |
|
| 44:37 | I put a little more oil in it may look like this go around |
|
| 44:44 | this, go around like this and all the curb has to be the |
|
| 44:50 | . So I would have filled a of this in, right, something |
|
| 44:54 | that. And so this would have , this would become oil wet, |
|
| 44:59 | would become oil wet and this would oil wet. So the fraction of |
|
| 45:02 | surface I would have a larger fraction the surface that's oil wet. So |
|
| 45:08 | my index is, my oil wetting would be larger, right, the |
|
| 45:13 | oil I put in. So the condition depends on the initial saturation. |
|
| 45:19 | if I'm on the plateau of the curve, I don't have much oil |
|
| 45:23 | there, we'll talk a little that'll mean more to you in a |
|
| 45:26 | , I guess I could remain, though I could have varying wetting |
|
| 45:32 | even in the same reservoir. So up on the cap pressure curve where |
|
| 45:37 | have had a lot of oil I'm close to all these, I |
|
| 45:41 | have a fairly, uh mixed wet . But gee, when I've just |
|
| 45:45 | a little bit of oil near the pressure of the cap curve, maybe |
|
| 45:49 | remains water wet. This makes your pretty interesting, right? So |
|
| 45:55 | where it's predictable, it's high up the cap curve or gee, the |
|
| 45:59 | thing I haven't filled only the corners the pores would remain water wet, |
|
| 46:03 | the rest of the grain, I would have a fairly high wetting |
|
| 46:08 | there. So the good news is where you're really interested. That's where |
|
| 46:14 | most oil is, right, et , or you're gonna leave the most |
|
| 46:18 | . And so that would probably be conditions you, you want to |
|
| 46:22 | OK? Is that OK? I pretty good. I'm proud of myself |
|
| 46:28 | my picture. We should sell you should sell it. You're drawing |
|
| 46:37 | wanna buy it. I don't think do. But, all right. |
|
| 46:45 | we answered that question we answered and know that that's the drainage phase, |
|
| 46:52 | ? And what we ability and this is the, this is the |
|
| 46:56 | phase. I should go back to old cursor. So this is |
|
| 47:04 | what's called the inhibition phase. And got a right click on this. |
|
| 47:12 | I all. Yeah, cool. contact angle, we talked about |
|
| 47:27 | This is a summary slide for It's the angle of fluid contact with |
|
| 47:31 | surface. It's measured through the fluid interest and depends on the fluids and |
|
| 47:36 | surface involved. And also it can on temperature. It can depend, |
|
| 47:42 | actually a little more complicated than but I'll leave it here for you |
|
| 47:46 | purposes of this class, right? actually pretty hard thing to measure in |
|
| 47:56 | surface tension is our next problem. one is actually a lot of fun |
|
| 48:00 | probably we're gonna have to draw another here. It's a ratio of the |
|
| 48:05 | force to the length along which the acts. So what does that |
|
| 48:12 | It's measured in dines per centimeter? that the same as a pressure? |
|
| 48:20 | are the units of a pressure, force per unit area? Yeah. |
|
| 48:28 | this weird thing, right? Uh so what it's related to is the |
|
| 48:34 | of whatever is in contact with that , right? So I should draw |
|
| 48:42 | picture here. So we'll see, gotta go back to my other cursor |
|
| 48:47 | I'm drawing another picture on my So I have something that looks not |
|
| 48:53 | as good. I have a beaker change color. I did better with |
|
| 48:59 | other ones color. I've got no and this is full of water. |
|
| 49:07 | . So beaker full of water and I'm going to, uh, actually |
|
| 49:14 | is green. Then I have a here. I keep pushing that and |
|
| 49:21 | it. So I, I have wire here, two vertical wires that |
|
| 49:27 | like this. I have a little here. This thing goes here and |
|
| 49:34 | goes around here. Right. And I pick this up out of the |
|
| 49:39 | . Ok. I'm moving this in direction. And so I go from |
|
| 49:45 | one position here, I've gone from to here. Have I expended any |
|
| 49:50 | doing that? Yeah, I've I have a film here, |
|
| 49:58 | I have a film of should be out with blue. Oh I don't |
|
| 50:03 | like it. So I have a here, right? Uh And so |
|
| 50:06 | film, I would ask you, what happens is I pick that wire |
|
| 50:11 | to the force required to move it pretend we did this on the space |
|
| 50:17 | . So gravity doesn't matter, So how does the force change as |
|
| 50:23 | pick this up? And I draw I make this film area larger and |
|
| 50:33 | . So I go from here to . That's one good guess but wrong |
|
| 50:49 | less other good guest but Ron. what are we left with stays the |
|
| 50:58 | . Absolutely. Right. So why that? So what are we |
|
| 51:04 | So what you have is, is , you, you have this beaker |
|
| 51:09 | , what causes surface tension? You beaker water, you have a surface |
|
| 51:14 | then you have molecules interior to right? They have no idea that |
|
| 51:19 | is there. And so this molecule the attraction from the other molecules |
|
| 51:25 | it's far, far enough away from surface. It has no idea it's |
|
| 51:29 | , right? So forces are I now get near the surface. |
|
| 51:33 | I have a molecule up here of molecule up here. It's feeling attractive |
|
| 51:39 | from its neighbors, but nothing OK. So it's literally pulled into |
|
| 51:45 | held into the liquid by those attractive . Do we have molecules escaping? |
|
| 51:52 | . Because they're zipping around, they a certain velocity, some of them |
|
| 51:55 | an escape velocity, get out. is why water evaporates out of a |
|
| 52:00 | , right? What happens when water , I've increased the velocity of the |
|
| 52:08 | to the point where they actually are escape velocity, right? And so |
|
| 52:12 | literally we we very quickly, The molecules are getting out, we're |
|
| 52:18 | it, right? But this excess right here, right? Is, |
|
| 52:24 | simply related to these attractive forces and us act like there's a tension |
|
| 52:29 | something pulling the fluid in. And what determines that amount of force pulling |
|
| 52:35 | in is simply the length of a or whatever along that surface tells you |
|
| 52:41 | many molecules are trying to pull it in, right? And so as |
|
| 52:45 | pull it out, this is why this force is measured in dines per |
|
| 52:51 | of the contact. So it's very from a pressure. And this is |
|
| 52:56 | , for some reason, not commonly that a surface tension is a very |
|
| 53:01 | property. You all OK? With , that's why we get the little |
|
| 53:07 | of mercury because the surface tension is high because mercury molecules like each other |
|
| 53:12 | lot. There's another foreigner if you and it's expensive. So I won't |
|
| 53:17 | this. But if you put a of florer on the table, it |
|
| 53:21 | is non wetting. But surface tension so low, it spreads out immediately |
|
| 53:25 | the whole surface and then evaporates, ? That's about the surface tension being |
|
| 53:30 | low. So it actually is not really attracted to the surface, it's |
|
| 53:35 | not attracted to the air and it's attracted to itself. So it doesn't |
|
| 53:40 | spreading out and then the surface area so big. It, it immediately |
|
| 53:48 | . We all set here. we'll see. So I have another |
|
| 53:53 | for you, right? This is , our friend. Remember Bert |
|
| 53:58 | We, we now have a system . We have one tube looks like |
|
| 54:05 | . I should get a pen, goes like this. And then we |
|
| 54:13 | a valve here. We have a . We have a big balloon and |
|
| 54:22 | little balloon. What would happen if opened that valve? That's one good |
|
| 54:35 | . But wrong. Uh Let me you a hint, your intuition is |
|
| 54:42 | here. What would happen if this a rubber sheet? What would happen |
|
| 54:50 | the force as I extended it? is Hook's Law as my distance got |
|
| 54:56 | , right? My force would get . This is probably what most of |
|
| 54:59 | were guessing because you're familiar with elastic . That's what your guess is based |
|
| 55:05 | it. It's good intuition because you're used to soap bubbles. You were |
|
| 55:09 | , you're used to elastic properties, ? Dealing with those. Yeah. |
|
| 55:14 | what what happens here is this thing wants to reduce the amount of molecules |
|
| 55:20 | the surface. So this thing will your your uh the curvature here is |
|
| 55:27 | and so this one actually will get for a film and actually go to |
|
| 55:33 | and will expand that bigger one. tamer used to give this demonstration in |
|
| 55:40 | when he gave Caity lectures. So , you know, have some sort |
|
| 55:52 | intuition for what a surface tension At least the idea that it's different |
|
| 55:57 | properties that you're probably used to hook kind of materials, right? Rubber |
|
| 56:02 | whatever uh soap bubbles. I what happens if you have two |
|
| 56:07 | small soap bubbles or two small drops liquid on a table, they get |
|
| 56:12 | to each other, they coalesce, ? You are used to that, |
|
| 56:17 | ? Why do they do that? energetically favorable for them to do |
|
| 56:22 | And it's similar here, the small , the small bubbles go away and |
|
| 56:27 | to form the big bubbles. That you, you are familiar with. |
|
| 56:36 | . And it takes energy. If have a big bubble and you hit |
|
| 56:39 | , you add a lot of you create a lot of small |
|
| 56:43 | but you have to add energy to system to make that happen that we've |
|
| 56:50 | done, right? We're good. , I like physics. So |
|
| 57:00 | right? I'm never sure whether this helps you or not. What kind |
|
| 57:06 | pressure do I have to add? I force fluid in here to get |
|
| 57:11 | liquid level to rise, it's actually GH so I have to add |
|
| 57:19 | But what happens is that the whole will rise equally all at the same |
|
| 57:25 | . That's because energetically, right? doesn't take any more energy to put |
|
| 57:30 | here than here than here. So is an example, I gave you |
|
| 57:34 | example of a capillary array of I'm gonna enter all of them at |
|
| 57:38 | same time. And so I would liquid in all kind of simultaneously. |
|
| 57:44 | this was a rock, this would very different, which is, I |
|
| 57:50 | this case, what's gonna happen is are gonna reach the largest pores in |
|
| 57:56 | rock. And I talked about this little bit yesterday and then we get |
|
| 58:00 | smaller and smaller pores to as we more and more of my non wedding |
|
| 58:06 | , right? And then we get to where we fill most of the |
|
| 58:10 | . Now we're putting it into the in that portion. So because |
|
| 58:14 | we don't have a single energy that would go into. This didn't |
|
| 58:21 | I don't have to show it, that's supposed to give you some |
|
| 58:27 | So four rocks, we have capillarity rocks. We have two opposing |
|
| 58:33 | What are the two opposing forces that what my distribution is? We have |
|
| 58:39 | pressure. So by cap pressure they, they, they mean the |
|
| 58:44 | , the amount of force that you to apply to get a non wedding |
|
| 58:49 | into and displace a wedding phase. what they mean. And what supplies |
|
| 58:55 | forces are the buoyant pressure. The that oil has a lower density than |
|
| 59:03 | . So oil wants to rise above water and it will, and that |
|
| 59:08 | a net pressure related to that Difference in them. The the water |
|
| 59:14 | wants to displace that oil. So water wants to rise. Yeah. |
|
| 59:20 | you, you have the Catholic pressure right again and why we, we |
|
| 59:25 | these are forces you have to What, what actually is that |
|
| 59:30 | You are overcoming in a water, rock with a non wedding phase, |
|
| 59:35 | actually have that, that wedding phase attracted to that surface and you have |
|
| 59:41 | actually overcome that attractive force. in order to push that fluid |
|
| 59:47 | Yeah. And then what supplies that is the buoyant pressure forces. So |
|
| 59:56 | , we're, we're about as complicated we're gonna get in this course. |
|
| 60:00 | . So here and we, we literally have done this in the lab |
|
| 60:04 | we saturated samples. Yeah, you do a fair job if you have |
|
| 60:08 | , if you have a really water rock, that's real porous and |
|
| 60:12 | You actually can sit there, put rock in the beaker, you can |
|
| 60:17 | the water rise in the rock, fact. Yeah. And uh uh |
|
| 60:23 | actually pretty much displaces all of the in the rock. Even more interesting |
|
| 60:29 | when you freeze that sample, you it from the bottom up and you |
|
| 60:33 | watch the for water come out the of the rock when you do |
|
| 60:36 | if you do it right. So is ideal what the saturation profile would |
|
| 60:42 | . So we have this, this is attracting the water, water gets |
|
| 60:46 | into the pore space. It's getting in this case by the gravitational |
|
| 60:53 | Yeah. And so how high it get. And uh it depends on |
|
| 60:58 | attractive force which is related to the surface area, the amount of surface |
|
| 61:04 | that's attracting the flowers and it will up in equilibrium with row GH the |
|
| 61:10 | force trying to pull the water back the liquid phase. You OK. |
|
| 61:17 | us, that's an inhibition experiment. the way, I think that's reasonably |
|
| 61:28 | . It's just based on the cap my saturation is. So a little |
|
| 61:34 | more terminology, this is called the water level. So what that pre |
|
| 61:39 | level means is there is zero capo there. It means the pressure in |
|
| 61:45 | water phase and the non wedding phase the wedding phase and the non wedding |
|
| 61:49 | are equal. So there is no force trying to push anything anywhere at |
|
| 61:55 | point right then we have here, is called the 100% water level, |
|
| 62:04 | often gets confused by people. This the point from here to here there |
|
| 62:12 | 100% water saturation in the sample because have not gotten to a high enough |
|
| 62:19 | that we can displace that water. no water goes into the sample. |
|
| 62:25 | is 100% water level is the If you remember, we call this |
|
| 62:29 | displacement pressure. Those two terms are with each other 100% water level and |
|
| 62:36 | displacement PD if you remember, Pressure, displacement pressure, right. |
|
| 62:44 | these are all things uh that you asked on the final, by the |
|
| 62:49 | . Yeah. And here we have known as the critical water saturation or |
|
| 62:56 | producing water level. So why is also called the critical water saturation? |
|
| 63:02 | here we have higher non wetting This is low water saturation, 100% |
|
| 63:09 | here, 0% water here. And what will happen? And remember I |
|
| 63:14 | about this as we have more and oil as we move this way. |
|
| 63:17 | we have less and less oil, water phase, actually, at some |
|
| 63:21 | will cut and act and be able flow. That's called the producing water |
|
| 63:27 | . That has high economic value. where we start to produce water. |
|
| 63:34 | much is water worth? If it fresh water, it may be worth |
|
| 63:39 | . Right. However, saltwater we got plenty of that. |
|
| 63:43 | It's three quarters of the earth's surface with that stuff. Right. |
|
| 63:48 | not just that, but you got Taine Xylene floating around in it and |
|
| 63:52 | these things, maybe a little H S or whatever, you're gonna have |
|
| 63:56 | pay to get rid of that Yeah, he can't just dump it |
|
| 64:00 | the ocean without getting in trouble and fine. Yeah. So you don't |
|
| 64:07 | to do that. All right. this, a lot of times that |
|
| 64:11 | water level where the water phase connects with each other becomes a continuous |
|
| 64:17 | . Is the economic limit of a , or close to the economic limit |
|
| 64:20 | a well. So as, as produce oil, I move down this |
|
| 64:25 | at some point, I'm gonna start water and then, yeah, I |
|
| 64:28 | to pay to get rid of that . So, uh, depending on |
|
| 64:33 | much water you produce, how far , you might be able to produce |
|
| 64:37 | little water, but it's uncommon to able to produce 90% water and 10% |
|
| 64:44 | in the gulf that certainly that you plug and abandon that well. |
|
| 64:50 | And then my last part of the , right, it's called a, |
|
| 64:54 | called a critical water saturation or a point saturation. How you, how |
|
| 64:59 | get that? The kind of rule thumb there's no uh rigorous reason to |
|
| 65:04 | this. The draw tangent here, tangent here and move up vertically from |
|
| 65:09 | point. That's the critical water And this is the cap height above |
|
| 65:15 | water level where it's gonna occur. my last one, my, my |
|
| 65:24 | one here is basically residual water. called sometimes mistakenly called coate water, |
|
| 65:30 | it is not coate water geologists should about this, in particular, uh |
|
| 65:37 | was here, she went and uh to you about it, right? |
|
| 65:40 | isn't coate water means the original water was in place when the rock was |
|
| 65:45 | . This is not that water, water's been replaced, right? So |
|
| 65:50 | fair to call it residual water. fair. But uh a lot of |
|
| 65:54 | it gots called coate water. It not coate water geologists in particular get |
|
| 66:02 | . Yeah. So that, that point, that critical point saturation is |
|
| 66:09 | value is the producing water level is the saturation at which we first |
|
| 66:14 | to produce water. It's called a point. A critical saturation. What |
|
| 66:21 | means is that's the point where the phase has connected across the whole length |
|
| 66:26 | your sample across some critical length. also called a percolation threshold, |
|
| 66:33 | Whereas I add individual segments of this , ultimately, they connect up. |
|
| 66:42 | talked about this when we talked about models and they give you some ability |
|
| 66:47 | predict this if you're doing your network correctly. So we OK with |
|
| 66:52 | we OK with our residual water saturation or irreducible water saturation is more |
|
| 66:59 | It's the irreducible water saturation. So a lot of times this irreducible |
|
| 67:09 | is related to remember bound water that talked about with clays. It's related |
|
| 67:14 | the amount of bound water in a . Remember how I told you you |
|
| 67:20 | not get that water out of the . You cannot get to a high |
|
| 67:25 | capi pressure to displace bound water. you often when you measure a mercury |
|
| 67:35 | , which we'll get to in a , we when we get to |
|
| 67:38 | I'll explain to you how to correct . So free water level. The |
|
| 67:43 | time we're talking about, we have line formation tester. This is actually |
|
| 67:48 | it's most often measured. In is uh this kind of measurement you |
|
| 67:53 | in and what this is is uh is a tool you can go into |
|
| 67:58 | well or you can actually uh it looks a lot like a rotary |
|
| 68:03 | drill. You have a, you a arm that comes out, pushes |
|
| 68:07 | , you have a snorkel that penetrates mud cake and you start measuring |
|
| 68:13 | So we go down deep, we down deep and we measure this and |
|
| 68:18 | we get uh is a straight And this is predicted by Archimedes principle |
|
| 68:25 | be either what's called gamma, a specific weight of the water or |
|
| 68:33 | gamma is equal to row times G GH is a pressure. If you |
|
| 68:39 | below the surface, it's the pressure feel in the fluid, it's related |
|
| 68:43 | the density of the fluid. The small G, the gra 9.8 m |
|
| 68:49 | second squared, right? Uh Depending how far you the earth from the |
|
| 68:54 | of the earth, it varies a bit and then kind of the depth |
|
| 68:57 | the surface, you swim to the of the 10 ft end of a |
|
| 69:01 | pool. A lot of pressure on ears, right? You're in the |
|
| 69:05 | end, not much. It's all to that pressure simply related to the |
|
| 69:09 | of the water above you. That's that matters. Doesn't matter where I |
|
| 69:14 | in the swimming pool, all it is how deep it doesn't matter how |
|
| 69:18 | water is. Be below me, it matters is the amount of, |
|
| 69:22 | water above me, which provides that called Archimedes principle. So you can |
|
| 69:31 | it if you want at pressures. GH. So I get a nice |
|
| 69:37 | line that's called the water gradient at . So we have P SI per |
|
| 69:48 | . So that typically for brine is 0.43 P SI per foot. So |
|
| 69:57 | every foot you go beneath the the pressure goes up by 0.43 P |
|
| 70:03 | Yeah. Now we move a pole we start measuring pressures and lo and |
|
| 70:11 | , what do we get? We get a straight line. |
|
| 70:15 | However, the slope is different. . And that's because the density of |
|
| 70:20 | is different from the density of Row. GH still works. |
|
| 70:25 | But row is smaller. So my , my pressure increases more slowly than |
|
| 70:33 | does for water. What is this right here where it crosses, that's |
|
| 70:40 | the pressure in the oil phase is to the pressure in the water |
|
| 70:46 | That is, it's kind of at top of the slide. And by |
|
| 70:52 | way, yeah, very good. called the free water level. That |
|
| 71:00 | where what that means, the free level is zero capillary pressure. The |
|
| 71:06 | in the oil phase is equal to pressure in the water phase. So |
|
| 71:10 | is no net force trying to push oil into the rock. OK. |
|
| 71:18 | your water saturation would be in a wet rock at that point 100%. |
|
| 71:26 | would have no oil in the Now what happens as you move up |
|
| 71:31 | from this point? Right not sure drawn exactly right. But we will |
|
| 71:36 | to right a point where my buoyancy , right, where my buoyancy |
|
| 71:43 | which is the difference between the pressure the water phase and the pressure in |
|
| 71:47 | right, that pressure goes up. . And we will get to a |
|
| 71:53 | where that force is now big enough get oil into the poor space. |
|
| 71:59 | that will happen where on the cap , a lot of ways, a |
|
| 72:10 | of distance to go back. Where that happen at the 100% water |
|
| 72:20 | This is my free water level where start to get oil in the |
|
| 72:24 | which is here, my saturation drops 100% is is the 100% water level |
|
| 72:31 | called the displacement pressure on the Yeah. These are key ideas we |
|
| 72:38 | to get. Yeah. And as move on, we're gonna get more |
|
| 72:44 | more oil. And what will happen we get up to here, we |
|
| 72:48 | disconnect our water phase. So our phase is continuous and water will flow |
|
| 72:55 | all of these cap pressures where we that cap pressure. So we are |
|
| 73:01 | down here, we're producing both oil water. When we get to this |
|
| 73:05 | water saturation, my water phase disconnects not connected. So above this |
|
| 73:11 | this is where we want to be the cap curve. We produce only |
|
| 73:18 | . Remember perm curves. We are out our R perm curve onto the |
|
| 73:23 | pressure curve fair enough. So this where you really wanna be. Oh |
|
| 73:40 | our water. And this is literally people find free water levels. In |
|
| 73:46 | , they do exactly these measurements, will go in and measure pressures as |
|
| 73:50 | function at depth. They will you get data down to a certain |
|
| 73:55 | here. What happens here where in region is both phases are connected. |
|
| 74:00 | the tool gets confused and then you'll back to where only the water phase |
|
| 74:05 | connected somewhere in here. And then measure pressure in the water phase and |
|
| 74:10 | those two, you extrapolate those two cross. That's the free water |
|
| 74:15 | This is very commonly very applicable done the time. Probably the best way |
|
| 74:21 | get a free water level. People also try to get it off a |
|
| 74:26 | curve but doesn't work very well. water level is up hole from |
|
| 74:32 | Yeah. My Catholic pressure has gotten , it got bigger. And then |
|
| 74:41 | uh critical water saturation right? Was above that somewhere up here somewhere or |
|
| 74:50 | disconnect the water phase and I get a low enough water saturation. |
|
| 74:58 | Been known to get asked this on problems and elsewhere to literally solve |
|
| 75:04 | But you have to be able to two simultaneous equations, right? |
|
| 75:10 | you all know how to do So here's the holy grail and where |
|
| 75:14 | wanted to get and we're almost ready do the exercise. All right, |
|
| 75:18 | cap pressure, if you want to me like a week, we can |
|
| 75:23 | this. Uh, otherwise you can accept it. It's up to |
|
| 75:29 | So we could probably get to it the end of week after next. |
|
| 75:34 | there's a lot of ideas behind But what I would expect, I |
|
| 75:40 | you to know this equation And what mean by that, I don't think |
|
| 75:44 | have to derive it. What you to know is what the Catholic pressure |
|
| 75:48 | . And what's the definition of That's the difference in pressures between the |
|
| 75:56 | phase and the water phase? So literally when we cross the interface |
|
| 76:03 | oil and water, we will just there's a pressure drop, right? |
|
| 76:09 | the pressure in the oil phase will higher than the pressure in the water |
|
| 76:13 | , right? And that's the cap . So this is the, this |
|
| 76:17 | the pressure trying to force oil into poor system of the rock. So |
|
| 76:26 | equal to two because there's actually two , two directions of curvature. But |
|
| 76:33 | , I said, you have to me the two, this is the |
|
| 76:36 | tension. OK, that we're right? So it's the surface tension |
|
| 76:43 | the wedding phase. This is the of that contact angle that we talked |
|
| 76:49 | . This is the surface tension we about and this is the pore throat |
|
| 76:55 | that we've talked about multiple times, ? So that's one force, |
|
| 77:00 | That's the force that we have to to displace the wedding phase. |
|
| 77:09 | The other force that we mentioned already the buoyant force. So this is |
|
| 77:15 | good question. I guess we can where we are. What happens to |
|
| 77:19 | Catholic pressure as R gets smaller, happens to the force we have to |
|
| 77:25 | to displace that wedding phase, the the poor throat, the more surface |
|
| 77:31 | we have per unit volume. So pressure gets higher. That's why this |
|
| 77:37 | right. So the smaller this is bigger this gets. What what |
|
| 77:46 | What happens if this con if this angles 90 degrees sine of 90 degrees |
|
| 78:02 | . So what kind of, what of wedding condition do we have? |
|
| 78:06 | would have this property? So that that basically right Catholic pressure is |
|
| 78:12 | And so there is no relative force displace the fluid, right? Whereas |
|
| 78:17 | contact angle of zero, right, a cosine of zero, right is |
|
| 78:23 | . So it's the full, that that this phase is really attracted to |
|
| 78:28 | surface. Yeah, cool. So is, I guess this is funny |
|
| 78:40 | I'm Big Bang. He goes oh ? All right. And then our |
|
| 78:44 | Force is Archimedes principle. So that's equal to the difference in densities. |
|
| 78:50 | density of water is bigger than the of hydrocarbons. So that term positive |
|
| 78:54 | . Little G. So row GH , my weight is my force, |
|
| 79:00 | ? My gravitational force and C is about goofy units, right? I've |
|
| 79:06 | feet, I've got grams, I've centimeters squared in this relationship. That's |
|
| 79:11 | we generate that. It's not my . OK. So what would we |
|
| 79:18 | at equilibrium? The good news for is that we are just gonna calculate |
|
| 79:23 | this is kind of initially. Fluids at equilibrium, nothing's moving. So |
|
| 79:29 | is simple, called balanced forces. those from your high school physics |
|
| 79:39 | I have a force this way, have a force this way that's equal |
|
| 79:42 | opposite. Am I accelerating? Am moving? No, I have balanced |
|
| 79:49 | . Therefore, our conditions in our are in conditions of balanced force. |
|
| 79:55 | I can set these two equal to other, which is what I'm gonna |
|
| 79:59 | next. Yeah, those two forces equal, we can set them equal |
|
| 80:07 | each other. We can solve for height of free water level and we |
|
| 80:10 | basically solve the problem, which is we're gonna do next. The last |
|
| 80:15 | we're gonna do today is go through exercise pretty sure we got enough time |
|
| 80:20 | 2 30 we might even get out little early. That's ok. Unless |
|
| 80:26 | strongly object, we can go on another lecture. Happy to do |
|
| 80:30 | So we, we'll see how far get. This can take easily an |
|
| 80:33 | , hour and a half to get the, to get through this. |
|
| 80:37 | we're almost ready to start it at . The cap pressure is equal to |
|
| 80:41 | and pressure we set these. And when you can, you not use |
|
| 80:45 | , if you have a flowing because you have fluids flowing. Now |
|
| 80:50 | notice when, when we, when up to this point, right, |
|
| 80:55 | is the expression we get, there's time in it, there's no acceleration |
|
| 81:00 | it, there's nothing going on other the balanced forces. So if fluids |
|
| 81:05 | moving, what do you do, geologists don't usually do it. Geophysicists |
|
| 81:10 | do it, but there's people called engineers who deal with that problem. |
|
| 81:17 | have we included there that you you're not dealing with booing fluids, |
|
| 81:27 | reservoir engineer, they run a reservoir . And what that reservoir simulator does |
|
| 81:32 | it includes not only capillarity, not these forces, but actually hydro hydrodynamic |
|
| 81:40 | , right? So basically they are how do fluids move under pressure. |
|
| 81:47 | we lower our well bore pressure, moving fluids into the well bore, |
|
| 81:52 | actually shearing fluids, we're doing all of cool stuff now, right? |
|
| 81:57 | are flowing everywhere. You might have influx. So they're modeling all of |
|
| 82:02 | . This is kind of the major of their job that's called a reservoir |
|
| 82:07 | . If you're not familiar with I'm guessing you've heard of them |
|
| 82:11 | right? So this is kind of a full time job. And so |
|
| 82:17 | they do this, they're deciding do need in fell well in fell |
|
| 82:21 | et cetera. Right. What should spot pattern be? So, how |
|
| 82:26 | wells do I drill? And so of money involved in that. That's |
|
| 82:30 | they get promoted a lot. And rest of us, not so |
|
| 82:34 | they're closer to the money. They have to dress better than us |
|
| 82:39 | Usually because of that. That was . A shell, the closer you |
|
| 82:46 | to the money, the better you to dress at the labs, you |
|
| 82:50 | dress pretty badly. Once you got the operating companies, it was tougher |
|
| 82:56 | if you were in the people who the economics. You were all suit |
|
| 83:00 | ties still. Money, money drives some reason. You have to be |
|
| 83:06 | dressed if you're close to money. never really understood that but got some |
|
| 83:13 | serious. All right. And so can you not use it? It's |
|
| 83:17 | the circumstances. You have a leaking , you, whatever you can't because |
|
| 83:22 | are moving and we haven't included any that. Physics. There's a lot |
|
| 83:26 | physics involved in that. All Cool. So, this is |
|
| 83:32 | uh, this is, uh, forms, uh, of, of |
|
| 83:37 | . Right. We're getting elevation above water level. We're gonna do all |
|
| 83:41 | that. We're gonna figure out how do that. That's a big part |
|
| 83:44 | the exercise. This is the equation gonna use. Why are we using |
|
| 83:49 | equation? Why does it look so ? We have mercury properties in |
|
| 83:53 | We have oil water properties in We have specific gravity here. We |
|
| 83:58 | mercury pressure here and it's because we gonna start with a mercury curve. |
|
| 84:04 | then we are going to convert that curve to an oil water curve. |
|
| 84:08 | we're gonna convert that to a height free water level curve. Then we're |
|
| 84:13 | put in our reservoir geometry, whatever is. And then we'll be able |
|
| 84:18 | figure out what saturations are as a of depth. So it's not as |
|
| 84:24 | as it seems and we'll go through step by step how to do |
|
| 84:29 | Yeah, better know how to do because it shows up on the final |
|
| 84:32 | a bit. Yeah, it's, relatively straightforward once you get through |
|
| 84:35 | once it's really not bad, maybe of you already done it before and |
|
| 84:39 | can go home now. No. it really is something you should understand |
|
| 84:44 | be able to do because people will about saturation height models all the |
|
| 84:49 | two ways to get oil saturations. of them is this. And so |
|
| 84:54 | I would like to do is go , we have enough information to do |
|
| 84:58 | exercise and then, so we'll spend hour uh uh we'll see we'll see |
|
| 85:05 | we get through it. How much we get through, then once we're |
|
| 85:09 | with that model, I can talk kind of the impact of these models |
|
| 85:13 | what they mean, that usually takes 15, 20 minutes to talk about |
|
| 85:17 | . What, what it means. , we're gonna hand out the exercise |
|
| 85:22 | , I'll get started. So, should do this exercise in the |
|
| 85:28 | I give it to you in the it's expressed here. If you do |
|
| 85:32 | do that, you will get lost you'll do it wrong. Yeah, |
|
| 85:41 | chair really is dangerous. Oh, you follow these steps. Exactly. |
|
| 85:49 | happy to go through. Uh If skip steps, I'm not gonna help |
|
| 85:54 | . So you need to do them the order that you're asked to do |
|
| 85:57 | here. And the first thing you is you, you take that saturation |
|
| 86:03 | height bottle. Thanks you, you that model right now. Let |
|
| 86:07 | let me read what the exercise right? You have a flat layer |
|
| 86:12 | . This means we don't have to deal with tilted reservoirs where my cap |
|
| 86:17 | pressure would be, my buoyant force be a function of position. So |
|
| 86:22 | that means flat reservoir. My buoyant is the same everywhere. All |
|
| 86:26 | it, we have two types of is gonna make it a little more |
|
| 86:30 | . We have a clay sand which labeled here. I've been nice to |
|
| 86:35 | on this. I could have and asked other students to identify which would |
|
| 86:39 | the clay filled sand and which would . But this is consistent with |
|
| 86:47 | So you should understand why that red is called the chlorite sand. And |
|
| 86:51 | you would know that anyways, I , why would you know that we |
|
| 86:55 | went through examples right, of ate curves as we had at clays. |
|
| 87:01 | happens? My displacement pressure gets larger my G gets larger, right? |
|
| 87:06 | then my irreducible water saturation gets larger I add clays. So hopefully, |
|
| 87:12 | obvious it's the red curve is the . It's the Shay sand. All |
|
| 87:18 | . Each of the two rock types up one half. We can all |
|
| 87:22 | by two, all depths in the are vertical depths and simple two top |
|
| 87:27 | the reservoir is at 7500 ft. bottom is at 8600 ft. Not |
|
| 87:32 | why I did that. The 100% level in the clean sand is found |
|
| 87:36 | be at 84 60 ft. Oil the non wedding phase like we talked |
|
| 87:42 | so far. And we've given you mercury Caple pressure curves for the two |
|
| 87:46 | . They are in pressure communication with other, which often at uh we |
|
| 87:52 | this in the engineering department, we that not happen. I will be |
|
| 87:57 | if you guys understand it at this . If you want to know what |
|
| 88:00 | would mean if they were not kept , in pressure equilibrium. Uh We |
|
| 88:05 | talk about that, but first problem should do is this one simpler, |
|
| 88:11 | ? Uh And they have, and that means is they have the same |
|
| 88:14 | water level. So I've already given if they weren't pressured communication, they |
|
| 88:19 | probably not have this same free water , they would have different free water |
|
| 88:24 | . So how would you handle So your first job, first task |
|
| 88:29 | is a scale, the vertical the cap pressure curve and height above |
|
| 88:35 | level. So how do I do ? I take this equation, I |
|
| 88:41 | the numbers in that I've given you I should get H is equal to |
|
| 88:46 | number times mercury pressure. So that's first job. Plug those numbers in |
|
| 88:53 | get that, get that proportionality I know what it is. So |
|
| 89:00 | know whether you got it right or . So we've given you all these |
|
| 89:06 | I've given you on the first page . I've given you the contact |
|
| 89:11 | I've even given you the parameters for Tamir the equation. The other thing |
|
| 89:20 | often ask which I don't think I've here is uh estimate a permeability in |
|
| 89:25 | two curves. So you might wanna that too. That's why don't we |
|
| 89:30 | that estimate the permeability by plugging the into two MS equation which I gave |
|
| 89:38 | in the notes. So first plug the numbers into this thing for |
|
| 89:42 | contact angles for the densities and for surface tensions and come up with this |
|
| 89:49 | between height above free water level and mercury pressure. You're welcome to work |
|
| 89:56 | on this if you would like sometimes it easier. Now you look |
|
| 90:07 | made the mistake of getting vaccinated like three of them. So it's |
|
| 90:16 | a fairly rough day. Get You gotta to get vaccinated. We've |
|
| 90:26 | friends die of pneumonia. So that a pretty good abject lesson. Never |
|
| 90:38 | to get blue cats. Oh, time in my career I changed my |
|
| 90:45 | . They were free right still. let me know when you get the |
|
| 90:52 | answer and then uh we can move . Yeah, it's already powerful. |
|
| 91:30 | can immediately calculate from a mercury curve the properties of all the fluids, |
|
| 91:36 | the pressure changes is related to a above the free water level. It's |
|
| 91:42 | pretty exciting stuff. The first thing do. Yeah, I guess I |
|
| 92:21 | you get one relationship. So I've given you all the densities, |
|
| 92:26 | given you all the contact angles for for the oil V five goes up |
|
| 92:35 | . Mhm. And mercury's 4 80 in the bottom and then the contact |
|
| 92:41 | for mercury is 1 40. It's there. Contact tale is zero, |
|
| 92:48 | is one up there. Specific gravity 1.05 and the 0.433. So |
|
| 92:55 | you plug those numbers in and you it right. You better get |
|
| 93:03 | Yeah. So. Mhm. I , even here you got 0.095 divided |
|
| 93:13 | 0.0866 that's gonna be one point Yeah, you were there. This |
|
| 93:23 | a little bit bigger. It's, , it's about 1.1. I, |
|
| 93:29 | just, no problem. That would cost you a lot of money. |
|
| 93:47 | right. So we got two people have 1.1. So we're gradually getting |
|
| 93:51 | uh three people at 1.1. So getting close enough, right? So |
|
| 93:59 | next thing you wanna do is scale your mercury pressure for height above |
|
| 94:05 | water level. When you plug the in, you'll get 1.1 actually minus |
|
| 94:12 | . But again, the minus sign ignore that because you're looking at heights |
|
| 94:15 | free water level. So this one's you can do in your head zero |
|
| 94:22 | 1.1 0 110 to 1.1 100 and to 23 34 45 56 60 et |
|
| 94:32 | . So then now you're starting to powerful, right? You have what |
|
| 94:36 | pressure would be right? Related these pressure curves or the distance above the |
|
| 94:45 | water level. So let's go ahead relabel that axis again. So the |
|
| 95:00 | , I guess for multiplying, I ignore the minus sign. It's, |
|
| 95:06 | gotta come out negative because your contact has to be greater than 90 |
|
| 95:11 | Right? That's negative. That's where negative came from. If that was |
|
| 95:15 | negative, you would be, you , you would not have an entry |
|
| 95:20 | . This would be oil wet. to be water wet, that number |
|
| 95:24 | got to be great in that. you get a minus sign and it |
|
| 95:27 | has to do with how much pressure we apply as we move up. |
|
| 95:37 | should only take you like 10 seconds relabel that axis, I can even |
|
| 95:47 | do that multiplication. So I'm not tell you what to do next. |
|
| 95:51 | this 01, 10 to 23 34 50 et cetera all the way |
|
| 95:57 | Hi above free water. Everybody got done. So what does this |
|
| 96:15 | So what we don't know is we have our depth tie point yet. |
|
| 96:21 | know the height above free water but that's an arbitrary position in the |
|
| 96:25 | . I don't know whether that's at ft 20,000 ft. I don't know |
|
| 96:30 | it is. I need a depth point. And so there, there's |
|
| 96:34 | points you can use that are commonly . One is the position, the |
|
| 96:39 | water level, I show you how get right uh in the lectures, |
|
| 96:44 | other is they could give you a for the critical water saturation, the |
|
| 96:48 | water level. You can get that a spinner survey, something like |
|
| 96:52 | Knowing what fluids are flowing uh or can use the displacement level, you |
|
| 96:59 | use the 100% water level and that can get off electric logs, uh |
|
| 97:05 | kind of saturation here and there. I gave you one of those three |
|
| 97:09 | type points, which one did I you depth of the water level? |
|
| 97:18 | water level even better. So where know the depth of 100% water |
|
| 97:23 | Where is that on the cap And did I tell you what sand |
|
| 97:28 | was in, in the clean So I know the depth of this |
|
| 97:35 | on the cap curve, that's the water level. That's the displacement pressure |
|
| 97:44 | that clean sand. Everybody see that given you the depth of this point |
|
| 97:50 | the cap curve, the 100% water giving you. Yes, giving you |
|
| 97:56 | depth of the 100% water level and clean sand. Yeah, exactly. |
|
| 98:02 | giving you that depth. How do get the depths to the free water |
|
| 98:10 | ? I know this mercury pressure. given you that the displacement pressure for |
|
| 98:16 | curve and gee I know the relationship that this by the way is 25 |
|
| 98:21 | si if I remember. Right. . And so I just have to |
|
| 98:26 | that by 1.1 to get how far that my free water level is I |
|
| 98:33 | a relationship between mercury pressure and height the water level. Did I take |
|
| 98:41 | the fun out of that for So, here. Yeah, I've |
|
| 98:45 | you that depth and you also know many P SI that is, |
|
| 98:52 | 25 25 P si. So I exactly what pressure that's at. I |
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| 98:57 | the relationship between mercury pressure and height free water level. 1.1. So |
|
| 99:04 | times, 1.1 is 27.5. So know my free water level is 27.5 |
|
| 99:11 | deeper than that displacement pressure. Yeah. So I know the depth |
|
| 99:23 | this. I know the mercury That's at, I've given it to |
|
| 99:26 | . It's 25 P si I know to relate mercury pressure to height above |
|
| 99:33 | water level. We just multiply by . So I know this is 27.5 |
|
| 99:39 | above my free water level. So need to do is take that depth |
|
| 99:44 | add 27.5 ft to it to get depths of my free water level as |
|
| 99:50 | tried to. Is that what you ? Yeah, you gotta add |
|
| 99:54 | It's deeper, right? This is my free water level. So my |
|
| 99:59 | water level is deeper. Everybody see to do that. I'm just gonna |
|
| 100:07 | them through that and we'll leave we're gonna do elegant. So, |
|
| 100:21 | know, you know how to get free water level yet. Do you |
|
| 100:25 | how to rescue your axis yet? did you do? This is why |
|
| 100:32 | doing it together. This isn't that . So, you know the relationship |
|
| 100:36 | mercury pressure and height above free water , you just take your mer |
|
| 100:40 | 1.1 you have tiny writing. so this is still 01 10, |
|
| 100:47 | 23 34 45 50 et cetera, ? That's my height above free water |
|
| 100:52 | . So do that relabel that you plug the numbers in, you |
|
| 100:58 | 1.1. Yeah, multiply by 1.1 gives you height above free water |
|
| 101:07 | OK. So that would be 100 10 ft. Next one's 2 23 |
|
| 101:13 | et cetera. So. Ok. . Got we got our free water |
|
| 101:27 | . All right. Now you get be a geologist. So what I |
|
| 101:31 | is I, I draw my geologic on top of this cap curve. |
|
| 101:38 | are my sands, right? So know the depth of the free water |
|
| 101:45 | , the depths of my horizons. . So I simply can put lines |
|
| 101:50 | here where my clay sand is and my clean sand is at. What |
|
| 102:00 | you say? Get your Yeah in in a in exercise. So |
|
| 102:10 | How do we get pre water I've given you the depth of the |
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| 102:16 | of water level. It's in the sand. A give me a second |
|
| 102:20 | turn the camera Yeah. OK. I've given you the depth of my |
|
| 102:33 | water level in the clean sand. I know the depth that that points |
|
| 102:38 | . That's also I've given you the pressure and you can try to read |
|
| 102:42 | off, but I also gave you displacement pressure that curve. It's 25 |
|
| 102:47 | si I also have a relationship between height of above free water level and |
|
| 102:55 | and it's 1.1. So 25 1.1 is 27.5. And so I |
|
| 103:02 | that my free water level is 27.5 deeper than my 100% water level. |
|
| 103:09 | all I do is add 27.5 ft the depth of my 100% water level |
|
| 103:15 | get my free water level. Thank . Sure. Yeah, you add |
|
| 103:36 | to to 10. So if I want to, yeah, that's the |
|
| 103:45 | thing I would label this axis in of depth. Once I know the |
|
| 103:49 | of my free water level, then first tick is 100 and 10 ft |
|
| 103:54 | that. So this is 8460. this would be 100 and 10 ft |
|
| 103:59 | . No, that's just our, the, the percent water, |
|
| 104:04 | So this is 100 and 8460 not . So your, your water level |
|
| 104:11 | pre water is 27.5 ft deeper 0.5 , 84 87. So I everybody |
|
| 104:23 | how to get the depth to the water level. 84 87.5 ft, |
|
| 104:32 | ? Ok. So I have this now I can relabel this axis in |
|
| 104:36 | of depth, this action. Because I know that this first tick |
|
| 104:44 | 100 10 ft above my free water . So at 84 87 right? |
|
| 104:50 | 100 and 10 ft, I'm getting here, right? As I move |
|
| 104:54 | and then minus 2 20 minus 30 minus 4 40. So I |
|
| 104:58 | relabel this now, in terms of , I use my depth tie point |
|
| 105:04 | get an absolute depth for this. then this is, I know this |
|
| 105:08 | 100 and 10 ft above my free level, 220 ft above my free |
|
| 105:14 | level, 330 ft, et cetera the way up. Yeah. My |
|
| 105:22 | water level zero capa pressure is my water level. That's what you |
|
| 105:32 | Well, it's shallower, right? mean minus, ok. Ok. |
|
| 105:35 | it's the 84 87 minus 1, , 84 87 minus 2 20 gonna |
|
| 105:51 | shallower. Ok. So yeah, everybody has their depths. Now, |
|
| 106:36 | can you geologists input to this? GEO gives you the depths of your |
|
| 106:45 | . So we gave you a geologic , which is the next thing you |
|
| 106:49 | in after you label this in terms depth. I know the depth of |
|
| 106:53 | chlorite sand, clean sand interface. know the depth of my top, |
|
| 106:58 | clean sand, top of my clay . Yeah, I've told you that |
|
| 107:04 | when we outlined the problem, uh just gets shallower as you move |
|
| 107:25 | we have to do that pressure by to get the height of a free |
|
| 107:36 | . Then I'm gonna start with It is negative because it's so you're |
|
| 107:47 | the de Yeah, it's a good to remember it. The information. |
|
| 108:05 | , that's uh 80 84 60 is 100% water level? I subtracted the |
|
| 108:14 | 47.5 I got. Ok. So 16th. No, no, |
|
| 108:31 | it's 84 87. You're gonna label tick marks. So we you you |
|
| 108:38 | up with the depth of here at Caple pressure. Sorry. Yes. |
|
| 108:54 | one was it? Oh, it's one with the picture of the cat |
|
| 109:00 | . So you know the depth of free water level, that's zero cap |
|
| 109:04 | by definition. You know that's 84 , I guess. Right? I |
|
| 109:10 | that depth. I know this tick is 100 10 ft above that. |
|
| 109:15 | tick is 2 20. Ok. is why we do it together. |
|
| 109:28 | a little confusing. 80%. You stuck and so you're doing way too |
|
| 109:39 | significant. Well, again, 1 , 2 20. That's fine. |
|
| 109:44 | you, you can do it wherever want, right? But you're gonna |
|
| 109:47 | , you're gonna have this uh 84 87.5, minus 1, |
|
| 109:53 | 84 87.5 minus 2 20. Is tick mark, et cetera and that's |
|
| 109:57 | you did. So these are your and if you did that, it's |
|
| 110:02 | . You're done with that. Now have what my capillary pressure curve, |
|
| 110:07 | is in terms of absolute depth, hide above free water level. This |
|
| 110:13 | where you needed that depth tie point all you had initially was relative to |
|
| 110:18 | free water level, right? But need to know what depth that's |
|
| 110:22 | It could be anywhere I could I write the problem, I can |
|
| 110:27 | my free water level anywhere I It just depends on how much oil |
|
| 110:32 | migrated structure or whatever. OK. now that I have depths, I |
|
| 110:38 | the depth, I know the depth my horizons of my two sands. |
|
| 110:45 | I can draw those on. I tell people just, just put |
|
| 110:51 | on this chart. So at the depth, you have the interface at |
|
| 110:55 | appropriate depth, you have the at the appropriate depth at the bottom |
|
| 111:00 | the chlorite sand. So where are ? So you just draw those |
|
| 111:08 | Mhm Now you can put the geology . So you, you need |
|
| 111:18 | you need to put in the geology . So the, so you just |
|
| 111:23 | to put in the depths where your are. What depths are your sand |
|
| 111:29 | ? Yeah. There you go. . And students oftentimes tell me, |
|
| 112:00 | , gee, you can't put the wherever you want. Oh, I |
|
| 112:04 | . Right. I'm God. I can put my geology in wherever |
|
| 112:08 | would like. Geology is independent. could have put those sands wherever I |
|
| 112:17 | . You might think about what it mean to move those sands around if |
|
| 112:20 | want. So like clean sand is the chlorite sand, right? Is |
|
| 112:35 | Indianapolis and my interface is halfway in , right? You go through the |
|
| 112:52 | exercise and then showing on the screen don't do that. We're supposed to |
|
| 113:01 | this out together. I'm not supposed give you the answer. This is |
|
| 113:07 | I say. It's a little bit for somebody online to do this. |
|
| 113:12 | the only way you would do that be to uh meet with them, |
|
| 113:17 | ? Or having a zoom meeting and tell them what to do and let |
|
| 113:21 | work through it one on one if not here now. So if they're |
|
| 113:26 | here now, that that's ii I , you see how much trouble people |
|
| 113:31 | with this. If you don't go it with them, they're gonna struggle |
|
| 113:35 | 68 hours and maybe not get it and get stuck. So I this |
|
| 113:41 | why I decided to do inverted A couple other exercises that are comparably |
|
| 113:46 | to this one. And we do same thing. Uh, usually if |
|
| 113:51 | go through it once with somebody they of get the ideas and the |
|
| 113:56 | I don't know what to tell We, we could have, we |
|
| 113:59 | have a, you have to do along with them. So, but |
|
| 114:06 | not familiar familiar with this so, , I would be happy to do |
|
| 114:12 | . They just would have to meet me at some point where, |
|
| 114:16 | where are they? Yeah, this , we have 33 person right |
|
| 114:23 | And what time zone are they Only? Only one student is in |
|
| 114:30 | . The other two are in, the, in the same time zone |
|
| 114:34 | we. So where are they? aren't they coming to class? Uh |
|
| 114:42 | they have no good reason and haven't to not be here and I am |
|
| 114:46 | willing to accommodate that. Oh, you have the option to be an |
|
| 114:54 | student. Well, so then they to be working this with us right |
|
| 115:03 | so they can share their screen if want with somebody and we can go |
|
| 115:08 | this. Um I mean, we have a solution written out for |
|
| 115:31 | So you, you could, you give them a PDF version of that |
|
| 115:36 | if you'd like, but they're gonna half the value here if they don't |
|
| 115:40 | it out for themselves. They will , I tell you learn, it |
|
| 115:44 | won't understand how to do it. . So we are recording right |
|
| 115:50 | So. Oh OK. Yeah. the, the 80 times the 1.1 |
|
| 116:02 | . And then, so, so your, put your geology on here |
|
| 116:07 | . So I want you to put the interface between the sands is where |
|
| 116:10 | top of the reservoir is where the of the reservoir is. So top |
|
| 116:14 | the, yeah, that's fine. . That's fine too, if we |
|
| 116:20 | this 80 times 1.1 that would give 88 and then a piece of, |
|
| 116:26 | that be the top? It's halfway between those? So that's where the |
|
| 116:30 | is, right? Oh halfway. , it's half, they tell you |
|
| 116:34 | half, half the top half. this the bottom half is that so |
|
| 116:38 | know the depth of that transition? you, they're off scale. |
|
| 116:43 | so be it right? So you put where that transition is, you |
|
| 116:48 | the depth of the transition. That's important thing. OK? So top |
|
| 116:53 | the reservoir is up here and and just put a wiggly line and |
|
| 116:59 | the bottom or whatever, what depth at. So, you know, |
|
| 117:19 | mean, the way to do if they want to follow along with |
|
| 117:22 | , they should be sharing the screen you and we could talk to them |
|
| 117:26 | it, right? We could talk way through it, that spot as |
|
| 117:32 | as I can do. The other if they're in Houston, they might |
|
| 117:36 | coming in for the portions right, we're actually doing things in the class |
|
| 117:42 | the class suffer. That's here for people who are not. We can |
|
| 117:46 | our best to accommodate it. I'm gonna go to their house. Thank |
|
| 117:56 | so much. Great draw that transition the transition between the two sands is |
|
| 118:10 | need to draw that um chart everybody that. Put the geology on their |
|
| 118:20 | on their cap curves. I don't so yet. All you need to |
|
| 118:25 | is at that depth. Calculate where depth is. It's halfway between the |
|
| 118:30 | and the bottom, right? And draw, draw a line across |
|
| 118:38 | survive. OK. And draw, a line across at that depth. |
|
| 118:45 | wherever that is, yeah, that about right? Really? 50. |
|
| 118:57 | . OK, great. So once have that line on, what does |
|
| 119:01 | mean the cap curve that controls is appropriate cap curve for that sand, |
|
| 119:08 | on the bottom is your clean So as you come up, |
|
| 119:12 | you wherever your free water level you're gonna reach first, you're gonna |
|
| 119:16 | in the bottom sand, you're gonna saturations are gonna follow that cap |
|
| 119:21 | then you're gonna transition to the other curve and your saturations will be related |
|
| 119:26 | that from there on. I So we're gonna go here and then |
|
| 119:29 | gonna bounce. What squiggly you think talking about squiggly? Um One of |
|
| 119:38 | slides and goes like that. Um you. So your saturation profile, |
|
| 119:57 | basically on this curve, you're coming from the bottom and we reach our |
|
| 120:01 | water level. It's all 100% water in the clean sand. Below |
|
| 120:06 | We get up to the 100% water and now we start putting oil in |
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| 120:11 | . We come up to this Now we transition to the other cap |
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| 120:16 | . It's a tighter sand. We less oil than we did in |
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| 120:20 | And we follow that cap curve up the top and that's my saturation |
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| 120:30 | right? So we fly between what do they want to know? |
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| 120:47 | between the new depth we labeled, have no idea what that question |
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| 120:52 | So first they need to do the right? Plug the numbers into |
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| 120:58 | OK? And then you're gonna get is equal to 1.1 times mercury |
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| 121:04 | OK. And you go to the curve and you label this zero times |
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| 121:11 | 100 times 1.11 10 to 23 34 et cetera all the way up. |
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| 121:17 | your height above free water level. we need to find, put |
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| 121:20 | use a depth tie point to actually out where in the subsurface we are |
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| 121:26 | with. So this is right. our height above free water level. |
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| 121:30 | I tell you the depth of the water level in the clean sand, |
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| 121:35 | 8460 ft. So this, I the entry pressure here is 25 P |
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| 121:43 | I gave you that right there. sand displacement pressure, right? 25 |
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| 121:51 | SI that's the 100% water level. 1.1 times that is 27.5. So |
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| 121:57 | know my free water level is 27.5 deeper. So that's at 84 87.5 |
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| 122:05 | . OK? And then I can 1 10 from it, 2 20 |
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| 122:10 | it 3 30 put things on a scale. Then I can put my |
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| 122:15 | on I know where my transition It's like 84 50 that I can |
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| 122:20 | my right where my sand transition, use this curve because I'm in the |
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| 122:26 | sand up to that point. I to transition red sand and that's my |
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| 122:32 | from thereof. That's basically the Yeah, I'm not sure it's it's |
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| 122:41 | mostly terminology, confusion. A little of that is done on purpose. |
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| 122:52 | water of the profile is but I , I mean that's fine. You |
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| 122:59 | a lot of people use a highlighter wave the line or whatever any of |
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| 123:04 | things is fine. So yeah. Yeah. Yeah. Depth of producing |
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| 123:49 | levels. So we're gonna be around 3 90. So then we plug |
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| 123:55 | . How do we get the critical saturation off this? We draw a |
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| 123:59 | , we draw a tangent, we straight up. So it's a little |
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| 124:02 | , always a little bit point past point of maximum curvature. So it's |
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| 124:07 | there and here it's, it's really in this sand. So you have |
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| 124:13 | single critical water saturation. It's about there. Then you would just, |
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| 124:18 | have to read off the, that line was just a graphical way |
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| 124:29 | get it. Draw tangent line draw a tangent line here. They're |
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| 124:35 | cross at a certain point and then gonna move straight up from that point |
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| 124:39 | this curve. That's your critical water . That is your producing water |
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| 124:44 | So that you would plug 200 into formula. Well, that's the point |
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| 124:48 | think it is? I don't know that triangle is. Oh Yeah. |
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| 124:53 | . So it's gonna be roughly So then we plug that and then |
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| 124:56 | , so for age and that's Yeah, you could, you could |
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| 125:00 | for your height above free water Sure. If I know the mercury |
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| 125:05 | or I can know the depth that can know the depth it's at. |
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| 125:13 | that's the mercury pressure. You went and you showed me right, you |
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| 125:19 | off the mercury pressure. And so I know that that would tell me |
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| 125:23 | height above free water level. And then my free water level |
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| 125:27 | I would add that height to it I'm reading this anyways, I could |
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| 125:32 | read off my depth. My depth be here off of this axis. |
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| 125:39 | , so, uh it's about right me. So that's the, that's |
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| 125:46 | , I don't know. G that, like the last question where |
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| 125:50 | says, estimate the depth of the water level. Yeah, that's the |
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| 125:54 | of the producing water level. I'm sure. I'd call it. Not |
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| 125:57 | why you're calling that G because it's . Oh sure. That's a good |
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| 126:04 | to call it G and then for credit estimate the permeability in these two |
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| 126:18 | use the two mir parameters plug into Tamir Equation for permeability and calculate what |
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| 126:23 | permeability in the two sands is. Everybody done. That's optimistic. So |
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| 126:41 | , you're doing great there. And the last question is producing water |
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| 126:46 | You're a tangent. If you're on tangent where it comes up, that's |
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| 126:49 | critical water saturation. That's your producing level. This is pretty iffy, |
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| 126:59 | ? Graphical rule of thumb, it's a little bit past the point of |
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| 127:05 | curvature. Hm Then you simply go up from that point to get straight |
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| 127:24 | . Yeah, to get the mercury . So OK. So and I |
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| 127:56 | to the mhm Right. Extra Calculate the terms. So I think |
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| 128:16 | close enough that I can wrap this up. So let's go ahead and |
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| 128:21 | that. So to show you the of this and hopefully drive home why |
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| 128:27 | doing this, then we're gonna Yeah. These are just examples of |
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| 128:43 | to plug in, right? Lab , lab conditions, microphone. I |
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| 128:48 | a microphone. Oh, you OK. All right. People can |
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| 128:52 | you. So people don't wanna Now, I'm happy to do this |
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| 129:00 | next Friday if you'd like. But that's up to you. We really |
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| 129:06 | to get her home. She's not good. So what do you want |
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| 129:10 | do? People aren't even listening to asking if you are listening. So |
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| 129:20 | guess implicitly that's the answer. I'm happy to let people go now |
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| 129:25 | people want. It's, it's like a half hour to wrap this |
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| 129:28 | I'm happy to do that next So let, let's just go ahead |
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| 129:33 | do that. I'm feeling guilty making stay. She's not feeling guilty. |
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| 129:38 | not feeling good. So let's wrap up. Don't get all three of |
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| 129:42 | vaccines at one time. This will you a chance to mull it over |
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| 129:46 | everybody else a chance to finish Just it's, we're, we're gonna |
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| 129:51 | about what the utility of this is it's a really powerful method is the |
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| 129:57 | line. It gives you, you , if you calculate the perms, |
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| 130:00 | gonna get permeability, you're gonna get , you can calculate volumes, you |
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| 130:05 | can answer all of the questions you to answer. So it's a really |
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| 130:10 | technique. I just wanna impress that everybody. So who, who's |
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| 130:19 | Is your flash drive? Yeah, fine. So we should shut off |
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| 130:27 | recording, et cetera, right? let you do all that stop. |
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| 130:46 | will you can, can you email answer to the to the exercise? |
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| 130:52 | email it to you. Thank We're coming up with this, you |
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| 131:17 | . Yeah. Mhm. And Bye bye. Ok. I |
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| 131:50 | you are ok. Where are you ? He, he said we don't |
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| 132:30 | what? Ok. So then there's other one too, right? So |
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| 132:36 | have the in class and now we , oh, yeah, I like |
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| 132:45 | again. Sp which I, So the exercise is due to gain |
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| 133:01 | Exactly. Ok. Ok. I'm, I'm at homework. You |
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| 133:07 | homework. No. No. So work is you next Saturday that you |
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| 133:12 | a week to finish it and then homework on campus like here. What |
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| 133:32 | you want us to do? I . Ok. All right. |
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| 133:41 | Ok. So, so was, , for me and you, |
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| 133:59 | yeah, so the, and, |
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