The Use of Routine and Special Core Analysis in Characterizing Brent Group Reservoirs, U.K. North Sea

Abstract

This paper describes the use of core analysis data, both routine and special, in characterizing the Brent Group reservoirs in the U.K. North Sea. The results of various special core analysis tests conducted over the years indicate that coring fluid, core preservation, and laboratory procedures are important in defining relative permeability and capillary pressure. Examples are given of the effect of oil-based mud filtrate on rock wettability; the effect of extraction, drying, and test procedures on laboratory waterflood performance; and variation of relative permeability among facies. Results also suggest how petrography may be used in assigning relative permeabilities by facies. Analysis of routine core data shows complexity within the Brent Group reservoirs even within relatively uniform sands.