Fit-For-Purpose Injection Control Philosophy for CO2–Hydrocarbon Gas EOR in Microporous Carbonate Reservoirs

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Offers a novel approach to CO2-EOR injection control under varying gas composition, relevant for CCUS research.

🏢実務担当者:Provides operational strategies for handling CO2 breakthrough and mixed gas injection in EOR/CCUS projects.

Carbon dioxide (CO2) enhanced oil recovery (EOR) has emerged as a key technology for maturing fields while simultaneously supporting large-scale carbon capture, utilization, and storage (CCUS) objectives. Globally, CO2-EOR projects have demonstrated the ability to unlock significant volumes of stranded oil, particularly in low-permeability carbonate reservoirs where conventional recovery mechanisms are ineffective. In parallel, the increasing availability of captured industrial CO2 has accelerated the deployment of CO2-based EOR as part of broader decarbonization strategies. Despite the growing body of published literature on CO2-EOR, most studies focus on relatively steady-state injection scenarios involving either pure CO2 or hydrocarbon (HC) gas. Far fewer address the challenges associated with dynamic injection composition over field life, particularly the transition from dense-phase CO2 injection to mixed CO2–HC gas injection following CO2 breakthrough and back-production. Such transitions introduce a continuously shifting operating envelope, where fluid density, compressibility, thermal behavior, and pressure–volume–temperature (PVT) properties vary materially with time. These changes have direct implications for injection control, flow balancing, reservoir integrity, and overall operability, yet remain insufficiently addressed in existing EOR design frameworks. The field examined in this study — a field in North of Oman — was discovered in the 1980s and targets a shallow (~1000 m TVD) Upper Shuaiba carbonate reservoir. The reservoir exhibits a pancake geometry, poor rock quality, tight matrix permeability, limited natural pressure support, and restricted crude mobility. Conventional development approaches proved ineffective: water injection failed to provide meaningful sweep or pressure maintenance, and since discovery, only approximately 2% of the original oil in place has been produced. These limitations prompted the selection of gas-based EOR as the only viable redevelopment option.

• semanticscholar https://doi.org/10.2118/232411-msfirst seen 2026-05-23 05:54:53 · last seen 2026-06-16 05:13:28