The Impact of Field a Produced Water with Benfield and Amine Carryover on Carbon Dioxide Injectivity and Storage

Abstract The oil and gas industries have recently launched rigorous decarbonization initiatives to address critical issues related to global warming. Carbon capture and storage (CCS) is a transformative technology designed to reduce atmospheric carbon dioxide (CO2) levels. The CCS Project seeks to process, transport, and inject the high-concentration CO2. However, a major concern with this process is the potential impairment of CO2 injectivity caused by the carryover of Benfield and Diethanolamine (DEA) solvents from the Acid Gas Removal Unit (AGRU), which compromises the effectiveness of CO2 storage. This research investigates the effect of the Benfield and DEA solvent carryover on the CO2 injectivity. The research encompasses the characterization of CO2 gas, reservoir-produced water, Benfield and DEA solvent, determination of total suspended solids (TSS) and total dissolved solids (TDS), and supercritical CO2 (scCO2) core flooding. Characterization of the CO2 sample from AGRU indicates a high concentration of CO2, ranging from 95% to 98% concentration. Reservoir-produced water contains 63.33 mg/L and 15,105 mg/L of TSS and TDS, respectively. Meanwhile, Benfield and DEA solvents have significantly higher TSS and TDS levels. The mixture of reservoir-produced water and Benfield and DEA solvents significantly increases the TSS to 1000.33 and 96.67 mg/L, while TDS increases to 215,745 and 37,735 mg/L, respectively, showcasing the adverse impact of the contaminants’ carryover. From the scCO2 core flooding, it was found that the Benfield and DEA solvents carried over and contributed to a reduction in core porosity of 3.92% and 2.91%, respectively. The porosity reduction was attributed to the combined effect of TSS and TDS, which precipitated as scCO2 was continuously injected. The drying effect of scCO2 accelerates the evaporation of resident water, leading to supersaturation conditions and solid precipitation. In conclusion, prolonged carryover of Benfield and DEA solvents adversely impacts the formation's porosity, reducing permeability and increasing injectivity and storage issues, rendering the CO2 storage process inefficient. These findings highlight the adverse effects of CO2 contaminants carryover on the CCS operation, specifically on CO2 injectivity and storage, providing precautionary insights for future CCS operations.