Upscaling CO_2 Foam for EOR as CCUS from On- To Offshore

摘要

Two major challenges in CO_2 enhanced oil recovery (EOR) are the high mobility of CO_2 and reservoir heterogeneity. High CO_2 mobility, related to the low density and viscosity of CO_2, compared to in-situ fluids can cause viscous fingering, gravity override, and flow in thief zones resulting in poor reservoir sweep efficiency and low oil recoveries. Mobility control foam can improve CO_2 EOR and CO_2 storage potential by mitigating unfavorable CO_2 properties and reducing the impact of reservoir heterogeneity. CO_2 foam injection involves injecting a foaming agent (surfactant) with CO_2 to generate stable foams in porous media. This work presents an incremental physical upscaling approach that moves from the pore- to core- to field-scale for characterizing and optimizing foam systems for CO_2 mobility control, EOR, and CO_2 storage. An additional focus was to visualize and describe in-situ fluid saturation dynamics during CO_2 storage processes. We address the challenges associated with transferring CO_2 foam EOR technology offshore, using lessons learned from an ongoing onshore pilot in the Permian Basin of west Texas. The aim is to encourage co-optimized CO_2 EOR and long-term CO_2 storage foam technology as part of carbon capture, utilization, and storage (CCUS) for offshore applications.