CO2-Foam Field Pilot Test in a Sandstone Reservoir

This paper presents an analysis of a CO₂-foam-injection pilot in the Salt Creek Field, Natrona County, Wyoming. The pilot was successful in demonstrating deeper conformance control and improvement in sweep efficiency, which resulted in 25,000 bbl of incremental oil. A 22% decrease in the amount of CO₂ injected also was realized as a result of better use of CO₂ compared with the baseline.

Introduction

Foam-assisted CO₂ enhanced oil recovery (EOR), commonly referred to as CO₂-foam EOR, has been proposed as an effective technology for correcting sweep inefficiencies caused by gravity segregation and reservoir heterogeneity. The central concept of CO₂-foam EOR is the in-­situ generation of a viscous emulsion of CO₂ and water stabilized by a surfactant at reservoir conditions.