Modified Brine Water for Simultaneous CO2 Mineralization and Enhanced Oil Recovery

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

🔬研究者:A novel dual-function workflow for CCUS-EOR with tunable chemistry, offering mechanistic insights into mineral precipitation and interfacial phenomena.

🏢実務担当者:A practical selection rule for optimizing CO2 mineralization and oil recovery using seawater-based additives, applicable to mature carbonate reservoirs.

🏛政策担当者:Highlights the potential of integrated CCUS-EOR processes to decarbonize hard-to-abate sectors while improving energy recovery.

Decarbonizing mature fields requires solutions that both immobilize CO2 and improve recovery without adding operational complexity. In Oman and the broader Gulf region, mature carbonate reservoirs, high formation-water salinity, and operational constraints on produced-water handling make seawater-based, low-chemical-intensity CCUS-EOR workflows particularly attractive. This study presents a seawater-based, dual-function workflow in which n-butyl amine (n-BA) is used to enhance CO2 uptake in Arabian Gulf seawater and subsequently enable controlled mineral precipitation, while concurrently producing an engineered injection brine tailored for carbonate enhanced oil recovery (EOR). Seawater was modified with n-BA at 0.3, 0.6, and 1.0 wt.% (CSWBA3/6/10), carbonated with CO2, and then alkalinized using 1.2 wt.% NaOH to trigger carbonate/hydroxide precipitation and brine reconditioning (SSWBA3/6/10). CO2 loading was quantified via total inorganic carbon (TIC), solids were characterized by XRD, and EOR relevance was evaluated through spinning-drop interfacial tension (IFT), contact angle on oil-aged Indiana limestone, zeta potential of mineral suspensions and oil-in-brine emulsions, and 27-day spontaneous imbibition in Amott cells. CO2 uptake increased with n-BA dosage (TIC: 1170 mg/L for CSWBA3; 1660-1680 mg/L for CSWBA6-CSWBA10). After alkalinization, pH reached ~10.35-10.74 and precipitate yield increased from 6.4 g/L (SSW, no amine) to 7.19-7.55 g/L (SSWBA6-SSWBA3), peaking at 9.5 g/L (SSWBA10). Mineralogy revealed a dosage-controlled transition from hydroxide-dominated capture at low dosage (SSWBA3: brucite ~69%) to carbonate-rich precipitation at high dosage (SSWBA10: aragonite ~44%, brucite ~3%). Interfacial properties were tunable: IFT was minimized at SSWBA3 (3.9 mN/m), while wettability alteration strengthened with dosage, achieving final contact angles of 30°, 23°, and 21° for SSWBA3/6/10, respectively (initial 149-156°). Spontaneous imbibition confirmed the design trade-off: SSWBA3 delivered the highest recovery (40% OOIP) via strong IFT reduction and favorable electrokinetic detachment, whereas SSWBA10 achieved high recovery (36% OOIP) alongside maximum carbonate locking via enhanced water-wetness. The results establish a practical selection rule for integrated carbon management and EOR: low n-BA dosage favors IFT- and electrostatics-driven mobilization (EOR-first), while higher dosage maximizes mineralized CO2 and wettability re-equilibration (sequestration-first), enabling reservoir-specific optimization using seawater as an accessible base fluid. Unlike conventional CCUS or smart-water studies that treat CO2 storage and EOR as separate objectives, this work demonstrates a single seawater-based process that simultaneously mineralizes CO2 and reconditions the remaining brine to optimize interfacial and wettability drivers of carbonate recovery.

• semanticscholar https://doi.org/10.2118/232562-msfirst seen 2026-05-23 05:55:37 · last seen 2026-05-27 05:04:52