On the Investigation of Gravity-Assisted Inert Gas Injection Using Micromodels, Long Berea Sandstone Cores, and Computer-Assisted Tomography

Abstract

ABSTRACT Downward displacement of oil by inert gas injected in a reservoir either at initial oil and connate water conditions or, in a reservoir depleted by waterflooding, results in very high oil recovery efficiencies under strongly water-wet conditions in both unconsolidated and consolidated porous media respectively. Advances made in directional drilling technology and increased understanding of the mechanisms and conditions that maximize recovery efficiencies can make the inert gas injection process of oil recovery1–3 feasible for a wide variety of oil reservoirs. This paper presents experimental results and discussion of a series of experiments designed for the study of: 1) production characteristics under immiscible inert gas driven gravity drainage conditions; 2) microscopic mechanisms of displacements and the determination of the rate of production by gravity drainage in capillary tubes having square cross-section; and 3) fluid distributions and oil bank formation using the x-ray computer tomography (CT) scanning facilities we recently established in our laboratory.