Carbon Storage Focused Reservoir Management: A Practical Example to Respond to Climate Change

Abstract

Carbon storage projects focusing on saline reservoirs have significant uncertainties in terms of reservoir and seal characteristics. Intelligent reservoir management of an oil and gas reservoir during primary, secondary and tertiary production phases produces an understanding of its key characteristics. Hence, the use of mature or declining oil and gas reservoirs to store CO₂ significantly reduces subsurface uncertainties. EOR (enhanced oil recovery) by CO₂ injection is a well-established technology for increasing oil and gas production rates and improving recovery. Considering climate concerns, using CO₂ injection for the twofold purposes of EOR and CO₂ sequestration/storage is an optimal choice. Our focused management clearly illustrates that an effectively managed and monitored reservoir is a superior candidate to gain from carbon dioxide injection for the twofold purposes - increasing production of hydrocarbon and CO₂ sequestration. Our research focuses on carbon management involving EOR and storage for an actual oil reservoir undergoing production for several years. A variety of key analytical and numerical techniques was deployed for a synergistic investigation of a mature reservoir involving several zones. The research utilized real field data from several sources involving performance of over three decades. We determined that the reservoir had a storing capacity of about five million metric tonnes, with an additional recovery efficiency of about 11% of OOIP (original oil-in-place). We learned that by skipping the waterflooding stage adds even more tonnes of storage. In addition, constant production of aquifer also creates supplemental CO₂ storage. Our research clearly identifies the huge potential for over 50 reservoirs for carbon sequestration in one region. Note that most of the reservoirs in this region contain large aquifers underneath, providing huge prospects for extra CO₂ storage.