Carbon sequestration and optimization of enhanced oil and gas recovery

Abstract

There has been a strong emphasis on the development of safe and economical carbon capture, utilization, and storage (CCUS) technologies in recent years because of rising concerns about carbon dioxide (CO2) emissions from fossil fueled power plants. Two technologies that show promise for CCUS application are enhanced oil recovery (EOR) and enhanced gas recovery (EGR), where CO2 is used as a working fluid to extract oil and natural gas respectively from depleted reservoirs. Permanent carbon sequestration is achieved as a byproduct due to subsurface fluid losses throughout the life of the system. In this chapter, numerical simulations of subsurface flow in EOR are conducted using the multiphase flow solver COZSim. For EGR simulations, the TOUGH2 (Transport of Unsaturated Groundwater and Heat) code is employed. An optimization code based on a multi-objective genetic algorithm is combined with COZSim and TOUGH2 and modified for EOR and EGR application respectively. Using GA-COZSim and GA-TOUGH2, the CO2 injection rates are optimized for both constant mass and constant pressure injection scenarios to manage the production of methane or oil for EGR and EOR respectively to ensure high output for the entire life of the system thus allowing for more efficient use of CO2. The results of this study highlight the scope of EGR and EOR technologies along with CO2 sequestration for consideration of deployment on a commercial scale. This chapter presents a review of the authors' previous work reported in the literature on EOR (Safi et al., Chem Eng Sci 144:30-38, 2016 [1]) and EGR (Biag et al., Energy 94:78-86, 2016 [2]) simulations and optimization.