Reservoir Permeability: Innovative Measurement Based on Novel Concept

摘要

A new model of permeability to clarify the true behavior ofrnfluid flow around producing wells is presented. A twodimensionalrnrepresentation of fluid flow in the reservoir isrninadequate in many ways. The direction of fluid flow in thernreservoir is neither horizontal nor vertical, and consequentlyrnthe traditional use of these two permeability components inrndetermining fluid flow characteristics has been misleading.rnRather, fluids flow from all parts of the reservoir and convergernto the wellbore, a very small spot in a big reservoir. The flowrnpattern towards the wellbore takes a conical shape where thernbase of the cone at the reservoir boundary and the head is atrnthe wellbore. In many cases, the flow reduces to thernperforations which are even smaller “ports” compared to thernhuge reservoir.rnThe need for a three-dimensional permeability becomesrnsignificant, and this term, complete with a technique forrnmeasuring it, is introduced here. A new method developed forrndetermining the 3-D (conical) permeability presented andrndiscussed. The proposed method is based on Darcy’s Lawrnemployed in a hemispherical scheme as the released gas flowsrnfrom the probe through the sample in this pattern. Thernderivation of the model used along with the numericalrntechnique utilized for solving are presented as well.rnPredictions of the model for air flow into a porous system arernpresented that appear to conform to the authors’ vision of fluidrnflow in petroleum reservoirs.rnThis new 3-D (tapering) permeability term should enhance thernaccuracy of the models used to represent fluid flow in porousrnmedia.