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  3. Where Are The Sweet Spots

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- [Voiceover] So now that we understand how boiling gas is generated and how they can result in essentially sweet spots. Either in-situ or where the things have migrated or where things have been expelled and through expulsion, they've filled up more spaces, where exactly, did everything go? So let's look at the question, where are the sweet spots from a geological perspective? First, lets take a look at migration pathways and likely zones of expulsion, likely pathways of expulsion, and also preferential enrichment. In this slide, I'm showing a diagram of the Anadarko Basin and essentially what this is, is this is a graphic from a study from the USGS headed up by Debra Higley who works in Denver. And Debra had studying the Anadarko Basin for many years and she's looked at, with her team, the places where the oil is generated and then where it is expelled out and the migration pathways with a goal of determining where the oil got trapped along the way in its path. Also the direction of flow and also where it ended up. I mean what is the extent of the migration. And it is very surprising, as you might expect, there is quite a bit that stays in the deep Anadarko Basin. But there's quite a bit that flows up through, and this is primarily the Woodford Shale. Woodford had developed fractures during generation using the mechanism we talked about before and it flows up primarily, in to what is now Kansas and along the way, it got trapped in other formations, all kinds of sands and primarily like in Pennsylvanian and also it got trapped in say the Hunton Dolomite, the Hunton line and also in the Mississipian as far north as Kansas. So it's really, really amazing how far the migration path can extend. Here's another diagram that displays the structure and the main faults so you can see where things are going and it also shows where the main reservoirs are. See, you can kind of see the structure, you can see the deep basin and you can see the pathways and it's quite interesting to see that the travel of the oil and gas occurred in punctuated intervals and they coincided with tectonic activity. So, why not yes the burial and the natural creation of nano fractures and micro fractures and the expulsion. What was also accelerating this was, tectonic activity, so the creation of major falls and structural movement accelerated and facilitated the travel of oil and gas. So I really recommend going to the USS and downloading their studies, they're excellent, and they're free. There are a number of studies that were published in the last five or six years that show the migration pathways and they also estimate there is eight remaining reserves and they estimate where they are. And not coincidentally, the places where the most migration pathways and the remaining reserves are, tends to be in what's in Oklahoma, what's now known as the Scoop Play. So, Debra Higley's work, USGS's work is essentially the map for leasing of the Scoop and drilling. Now how do we predict those migration pathways? Determine where on earth the oil would be migrating on and flowing. Her work of the Anadarko Basin is excellent and there has been, on other basins as well, primarily done by the USGS and also different state geological surveys and as well different universities, different researchers. So, they have looked at basin modelling and looked at the history of the basin. Essentially, BRAV, the deposition of organic matter, to burial, and essentially that the cooking going on in the thermal maturation, in the processes of temperature is looking at vitrinite reflectance and all sorts of different, useful tools, and indicators in order to get a sense of the geological history and in addition to that, looking at the structure and getting a sense of when you had major structural activity, when were the faults put in place, lack of temperature was there, what kind of fluids, the types of fluids that float through, extremely important hydrothermal fluids can be really warm and they can be really hot. All have implications for the generation of hydro carbons and also the way that they push through and also just looking, taking a look at major regional faults. Were those important in conducting oil and did they function as conduits migration pathways out? Were there fault traps? Are there lots of areas where along those faults it would be good tracking mechanisms? These are all very important and very, very fruitful areas of investigation that can help you predict where you're going to have. Not just reservoirs but also sweet spots are essentially many stratigraphic traps. So in predicting migration pathways, you're going to find traps of all sizes and degrees. You'll have the big ones and little ones. So to recap, let's just take a look at the characteristics of migration. Fist of all, migration happens in pulses, where there's pressure build up and expulsion and the creation of nanofissures, nanofractures. It also happens in pulses triggered by tectonic events and structural activities. It's also powered by pressure and temperature changes that are from variable flow in the mantle. So essentially tectonic activity again and movements along plate boundaries. It's not an even flow, migration does not just flow out like, you know, water down a stream, it's in pulses. And hydrocarbons tend to stay behind in areas of optimal storage. In other words, where there is differential and preferential porosity, they stay behind when they're trapped when there are permeability barriers. So they stay behind in places where they can be stored in areas of porosity and also where they're trapped. If you selected "E," that was correct. If you selected "A," that was correct but it was not the only correct answer. "B" is also correct. If you selected "C," Food-grade reservoir fluids, well, that's kind of a problem because sweet spots aren't actually sweet in taste. They're sweet in other ways, in terms of being productive. And if you said, "Nothing much to offer," well, it's not really true because why would a sweet spot be sweet except that it's something good.