This doesn’t occur in the majority of geological versions as well as most petrophysical models. Rather we aquire NMR logs, core evaluation flow zones and stone types in efforts to utilize porosity to deal with permeability variations whilst dismissing that which we have to get a more affordable, more potent prediction of permeability. Hydrocarbon pore volume gives a superior default prediction of intergranular stone permeability across different reservoir types and distinct stone types compared to porosity, surely as well as saturation. The fluid zones test ought to be performed first to guarantee Sw ~ Swi. Each petrophysicist understands that fantastic stone comprises more hydrocarbon than inferior rock at the exact same capillary pressure (elevation ), but neglects to utilize it!
Additionally mercury data generally can’t be utilized for Sw-Height at a clayey, very low permeability rocks unless Cation Exchange Capacity and Clay Bound Water corrections are made. Throughout a mercury experimentation a water period isn’t present to moist the clays and delicate pores and the germ bulldozer will barge its way via fragile clay lined throats, therefore, unlike air-brine information, germ saturations don’t supply an analogue for all these reservoir saturations. Mercury data supplies pore throat size advice for stone typing. This absence of a water period is particularly significant here where Clay + Capillary Bound Water is a substantial portion of overall porosity, as indicated here from the 100% difference between the air-brine and germ data calculated HPV to the exact same reservoir elevation. Hence, regardless of the demand for a resistivity independent majority volume hydrocarbon these mercury data possess limited capacity to provide a usefully accurate dm-m scale complete rock storage capability in stones under about 30mD or higher CEC freshwater shaly reservoirs. Nevertheless, using MCIP data uncorrected for peppermint and clay bound water offers high HPV that’s possibly a more sensible explanation for its continuing usage.
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