AN EXPERIMENTAL ANALYSIS IN EVALUATING ORDERING CRITERIA FOR COMPOSITE CORE ARRANGEMENT IN SPECIAL CORE ANALYSIS

Abstract

Composite cores of core plugs from different heights of an exploration well core are often used for routine and special core analysis to evaluate an oil reservoir. The question is whether or not the order of the core plugs in the composite core make a difference to the absolute and relative permeability measurements? The seminal work by Huppler (1969), proposed ordering individual core samples harmonically in a composite core in order to match the overall permeability. Langaas (1998) proposed ordering the core samples in decreasing permeability for effective relative permeability measurements, based on theoretical framework of North Sea sandstones. In this paper we tested the methods proposed by Huppler and Langaas experimentally. Core samples with permeability ranging from 50 mD to 2 Darcy were used for this work. The orientation of the core samples was tested for permeability and relative permeability and compared with the theoretical model developed by Langaas. In addition to the experimental work, simulations were performed with the three different composite cores and the representative recovery factor was compared to provide the appropriate composite core arrangement.