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  7. Conclusion

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- [German] So some conclusions and observations. So as a conclusion, the upper Almond Formation in the Wamsutter Field represents some, it has some characteristics that make water saturation-height modeling a really worthwhile exercise. For instance, as I said before, the subsurface structure remain unchanged from the Eocene time, which was when hydrocarbon went into the reservoir, and the trap model has a strong stratigraphic component. A composite capillary pressure curve are built by combining the first and second stressed mercury injection intrusions with the centrifuge capillary pressure when the wetting phase is lower than 40%. So the fact that the clay-bound water corrected stressed mercury injection differs from the centrifuge capillary pressure at low wetting phase saturation could be an evidence that clay-bound water and dead-end pore space not associated to clay. An imbibition saturation-height model based on mercury extrusion might be an inaccurate representation of the water saturation near the imbibition free water level. So we, in this paper, we present a practical way to combine mercury extrusion data with counter-current imbibition maximum trapped gas forbidding imbibition, primary imbibition models. So differences in pore structure arise from difference in primary depositional fabric and rock frame mineralogy, and their subsequent diagenetical overprint. And you have seen that this has a strong effect in porosity and permeability space. So given that depositional and diagenetical facies display different slopes in pore open space, it is not surprising that Thomeer and Brooks-Corey parameters correlate better to petrophysical properties when samples are sorted by those depositional facies. The zeolitic character of these reservoirs and the rock quality variation over small vertical distances make the matching exercise quite challenging. So the accuracy of the interpreted free water level is approximately one or two hundred feet. So in other words, I'll show you here what are perhaps the best examples of free water level matching, but you will see, so if you do this exercise, you will see that, in other wells and in other reservoirs, you'll see that you may have a good agreement in some reservoirs and have a lower quality agreement in others. So you end up kind of doing a trade-off between all your reservoirs. And the plus/minus water saturation accuracy, if you will, could be per approximately 10 saturation units. Assuming that the reservoirs were fully charged with hydrocarbon, the drainage saturation model is a key parameter for flagging departures from expected rock quality-dependent water saturation. A common free water level can only be used in wells located within a few miles of each other. The reason is the source reservoir configuration. So we couldn't, in the few wells that we have looked at, we cannot extrapolate that free water level over long distances because these reservoirs are locally charged from the cause that I just showed you. And finally, the mechanism by which these uppermost shoreface bars result in the high water saturation is still unclear. So in the second example that I showed you, so imbibition is the most likely thing affecting the reservoirs, but we are not, we need to look at more wells. And I cannot understand whether reservoirs were fully charged and did the trap leaked or, and this is the case of primary imbibition, or the reservoirs were not fully charged due to compartmentalization. And this different compartment that you may have in reservoirs are mostly caused by presence of coals, shales, and carbonate-cemented layers.