- [Instructor] So, then, the last part I just wanted to show the benefit that this technique brings when you're shooting sidewall cores. In this case that we looked at before, where you have very poor mobility or movability of the oil, you've got heavy oil situation, the log looks like this, and when you shoot a core, a sidewall core, now the core has been drawn to scale with these depth of investigation lines. Cores typically recover about an inch, maybe a little bit more, maybe a little bit less, sometimes only like half an inch of sample, and we get interesting overlap between the shallowest measurement on the dielectric and what the sidewall core sees. So in a situation like this, if you have a log response that looks like that, you can be pretty confident that your core saturation that you come up with is gonna be unaffected by invasion, and is gonna give you a true oil saturation, as opposed to this situation, where you know you've got movement, the model shows invasion, sweeping back of oil. Take a core here, and your oil saturation is gonna be reduced by invasion, and so when people in these heavy oil environments or diatomite are required by their reserve accounting companies to take some sidewall cores to either calibrate the log response or to certify the reserves, if you don't have all four curves available to you, you're not gonna know when this is happening, and you could end up with a pessimistic core that pulls your reserves down. And as a matter of fact, when I was doing the research, back when dielectric was first introduced, 30 years ago, 20 years ago, whatever it was, there were papers that said you could replace cores with dielectric, and in heavy oil this would work great, because everybody knew that 16 gravity or lower, the oil didn't move in the invasion process. Well, that is completely untrue, which we can see by the data that we have. So this is pretty valuable. This is an example of heavy oil, a diatomite well where we have, now I've just presented the one-inch dielectric curve, for comparison to the core, and you can see lots of oil saturation, indicated by the separation. And cores were shot at A, B, and C. The core saturations, the oil saturations, were plotted here, in the stars, and the oil saturation calculated from the one-inch and the total porosity is here in pink on on a zero to 100% scale. Data through here, you can see the A was 39%, B was 34 1/2%, and C was 34%, so you've got pretty good agreement here and here. Here, the core is underrepresenting the oil compared to the one-inch dielectric. Now, once again, with only one curve, you really are limited to be able to see what's going on there in terms of movement. So when you add the other curves in here, you can see that at zone B there's a high amount of movement, a lot of invasion took place here, but at A and C there aren't, and so the saturations from these cores could be used to calibrate any sort of log analysis, or used in reserve calculations. But at zone B, if you did that, you'd be way underrepresenting the amount of oil there. So the one-inch measurement calculates 42% oil saturation. The four-inch, and this is the purple, is the curve that's calculated with the deepest reading, or the four-inch measurement, is 69% oil saturation, it's a 20, 25-unit oil saturation difference just by going from one to four inches. So this shows the benefit of havin' this information, but as well, when you do have the invasion process, havin' this deeper four-inch curve allows you to read a more accurate oil or water saturation. And the impact on reserves, again, when you're looking at 60% porosity, the difference between 42% oil and 69% oil makes huge impact on reserves. In summary, the new technique with the Oil Saturation Invasion Profile is a straightforward observation of oil movability variations, which, in many of these reservoirs, directly relates to higher productivity zones with higher movability. We've already shown examples where optimizing your completion strategy based on this data provides higher oil production, in fact, the best wells in the field. And the deeper depth investigation and the identification of flushing allows you to better utilize your dielectric data. You won't be fooled by a flushed interval, or by interpreting a flushed interval without the knowledge of it being flushed. And then the benefit with the sidewall cores. Since this quicklook is available in the field, at the well site, you run the quicklook first, and then select where to shoot cores. You can put them in places that don't have any movement to get better virgin oil saturations, or if you wanna explore what's happening in the zones with movement, you can shoot 'em in there too, but you're doin' it with a knowledge of what's goin' on.