Journal Article

Water Impact on Adsorbed Oil Detachment From Mineral Surfaces by Supercritical CO2: A Molecular Insight

Gao, Rui, Yang, Leilei, Yang, Yulong, Hou, Jirui, Sun, Wenyuan

2024

Overview

Geochemical reactions are crucial for in situ CO2 mineralization underground associated with CO2‐enhanced oil recovery (CO2‐EOR) in a hydrocarbon reservoir. However, the presence of formation water and adsorbed oil on rocks generates physical barriers to CO2's access to mineral surfaces, which may yield impedance to CO2 mineral trapping that has yet to be accounted for. In this study, we mimic the dynamic oil detachment process using molecular dynamic (MD) simulation and analyze the influence of an adsorbed oil film on supercritical CO2 (scCO2) diffusion toward the mineral surface in the presence and absence of a water phase. Our results demonstrated a negative impact of water on oil film detachment by scCO2, which may weaken mineral reactions and is unfavorable for mineralized CO2 storage underground. Plain Language Summary Carbon dioxide emission has been identified as one of the primary factors influencing global climate change. Storing CO2 underground while enhancing oil recovery is a promising technology that can effectively reduce costs for carbon capture, utilization, and storage (CCUS). Mineral trapping, that is, converting CO2 to carbonate minerals through CO2‐water‐mineral surface reactions, is one of the major mechanisms for CO2 storage. However, residual oil adsorbed on rock surfaces after CO2 injection into an oil reservoir yields a physical barrier for CO2 approaching mineral surfaces. CO2‐water‐oil‐mineral interactions have yet to be thoroughly understood. Therefore, we conducted a series of molecular dynamics simulations to mimic the dynamic oil detachment process and unveil the impact of water on oil film detachment by supercritical CO2. We found that the presence of water strengthens the interactions between the oil and rock surface, which may give rise to a substantial delay in oil film detachment and weaken mineral reactions. Our results provide significant implications for the mineralized storage of CO2 in a depleted oil reservoir and CO2‐enhanced oil recovery and its consequent sequestration. Key Points CO2‐water‐oil‐rock interactions are investigated using molecular dynamics simulations scCO2 can collapse the oil film and channel out a path for CO2 diffusion Water exhibits a negative impact on oil film detachment by scCO2

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Barriers / Carbon capture and storage / Carbon dioxide / Carbon dioxide emissions / Carbon sequestration / Carbonate minerals / Carbonates / Climate change / Enhanced oil recovery / Global climate / Hydrocarbons / Mineralization / Minerals / Molecular dynamics / Oil recovery / Oil reservoirs / Oils & fats / Reservoirs / Rock / Rocks / Surface reactions / Trapping / Underground storage / Water