POROUS PLATES INFLUENCE ON EFFECTIVE DRAINAGE RATES IN CAPILLARY PRESSURE EXPERIMENTS

摘要

Capillary displacement using the porous plate technique has been used for decades to determine capillary behaviour in a reservoir.The disadvantage is that the technique is quite time consuming.During the last few years,different techniques,such as the membrane technique,have been developed to speed up the experiments.However,membranes have problems of enduring mechanical stress and resisting wettability change during an experiment.Other fast techniques,like the continuous injection technique,have been introduced in order to reduce the time required to obtain data.In this paper we present a technique with the use of a recently developed,hydrophilic and hydrophobic,layered ceramic porous plate.We document the properties of this high-flux porous plate both theoretically and experimentally,and compare the results against standard types of porous plates.Parallel experiments using standard industry porous plates have been done on both reference and reservoir rocks from the North Sea.The results of the study prove how the flux properties of porous plates affect the effective rates and stabilisation time during drainage.A much faster stabilisation at each capillary pressure step is achieved by minimising the flux restriction in the porous plate.Experimental turnaround time has been reduced by a factor of more than 5.Use of layered porous plates may lead to a new standard for the porous plate technique and could reinforce the interest of using the technique in core analysis.