Experimental investigation of CO2 miscible flood in West Kuwait

Abstract

As reservoirs approach maturity, the understanding and implementation of Enhanced Oil Recovery (EOR) techniques become essential to meet the world growing oil demand. EOR processes involve the displacement of one fluid by another. The major EOR methods in the petroleum industry include thermal, miscible and chemical processes. Miscible displacement methods involve the injection of solvents that will inter-mix with the reservoir oil to increase its mobility and reduce the oil saturation to low values in the swept zone of an oil reservoir. This work is part of Kuwait strong focus on EOR applications in Kuwaiti reservoirs to maximize the hydrocarbon recovery factors for a sustainable growth in oil production. This study is an experimental study that evaluates and investigates the miscible flood performance in Kuwait. An oil formation was selected as a candidate reservoir for this study after conducting EOR screening criteria. Core and fluid samples were collected and their properties were evaluated. Slim tube experiments were conducted to measure the oil minimum miscibility pressure with CO2. Coreflooding experiments were conducted to evaluate the recovery factor from different injection scenarios. The experimental injection scenarios included the effect of several design parameters including WAG ratio and number of cycle per WAG. These parameters showed different effects on the recovery factor. Optimum injection scenario was obtained which gave the highest recovery factor (WAG 1:2 and number of cycle 2). In this study, the in-situ miscibility achievement was quantified and evaluated at different injection scenarios. The outcomes of this work provide valuable information for future miscible flood field implementation.