3. RFG: Connectivity and Equilibrated Asphaltenes

- [Voiceover] - A rather dramatic example of this was shown in a Saudi case study, where the reservoir is giganic, 50 kilometers, and you can see there's a heavy oil rim this four-way ceiling anticline in my little color thing. The heavy oils indicate as dark color. We had a bunch of wells around the periphery, and we plot the asphaltene content, which is varying by a factor of ten over a height of 60 meters, and what you can see is that the points are pretty closely matching the line. The line is again, the FHZ EOS, but, with no adjustable parameters. So, this is a remarkable fit, showing that the asphaltenes around this 100 kilometer periphery are equilibrated. We would predict connected. This reservoir is put into production, and it's known to be one giant tank. So, this is working, and I just know that this is a huge gradient of asphaltene, so then a tar mat down below, and there was some discussion. "Is this due to a variation in thermal maturity?", so we checked, and there's the thermal maturity markers, and what you can see. You don't have to know what these are. If there's a variation of this plot then you would say, "I have a maturity variation." and if it's a straight, vertical line, "I don't have a maturity variation." So this giant gradient in this reservoir is not due to a thermal maturity gradient, and you can see some air bars in the data points, which is fine, but this is not a maturity gradient. This is an accumulation of asphaltenes from one of these RFG processes. I don't have time to go into those details right now. Okay, we have many papers on this reservoir, if anybody's interested.

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