REVIEW OF THE INTERCEPT METHOD FOR RELATIVE PERMEABILITY CORRECTION USING A VARIETY OF CASE STUDY DATA

摘要

In 2014,Gupta and Maloney1 introduced a novel method of measuring steady state relative permeability,called the Intercept Method. The Intercept Method entails a modification of a standard steady state procedure that incorporates multiple total flow rates at each fractional flow rate. The objective of the method is to measure data at each fractional flow rate that will permit simple analytical calculations to correct differential pressure(hence relative permeability)and saturation data for the effects of capillary pressure. The Intercept Method is intended to provide a corrective technique without the need for additional supportive analyses,such as capillary pressure and in situ saturation monitoring(ISSM),or as an alternative approach to the current considered best practice of numerical coreflood simulation,which generally requires the specified additional data. Consequently,the Intercept Method is of interest to the global industry in regions and/or laboratories that do not possess state-of-the-art equipment,or for its cost saving potential. However,before employing this new method,it was important to the authors to investigate its validity across the range of rock properties,sample dimensions and wettabilities experienced in commercial SCAL coreflood experiments. This study thus draws on a variety of relative permeability curves(and supporting data)from various global core studies,originally derived by typical relative permeability methods plus coreflood simulation. From these data,we use SCORES to simulate the expected results of multi-flowrate steady state experiments and use the Intercept Method to derive and compare the corrected relative permeability curves. Results highlight criteria under which the method does not provide fully corrected data. The paper explores these criteria in more detail.