文献类型：期刊文献

英文题名：Minimum miscibility pressure determination considering three-hydrocarbon-phase displacements for CCUS applications in tight/ shale formations

作者：Chen, Zhuo[3];Li, Ruixue[1,2];Du, Yifei[1];Wang, Xiaozhen[1];Zhang, Xin[4];Yang, Hong[1];Shi, Jialin[5]

机构：[1]Chengdu Univ Technol, Coll Energy, Chengdu 610059, Peoples R China;[2]Chengdu Univ Technol, State Key Lab Oil & Gas Reservoir Geol & Exploitat, Chengdu 610059, Peoples R China;[3]Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2V4, Canada;[4]Univ Alberta, Sch Min & Petr Engn, Edmonton, AB T6G 1H9, Canada;[5]East China Univ Sci & Technol, Sch Chem & Mol Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2026

卷号：286

外文期刊名：APPLIED THERMAL ENGINEERING

收录：;EI(收录号：20255019675810);WOS:【SCI-EXPANDED(收录号:WOS:001637533700003)】；

基金：This study was supported by the project from National Natural Sci-ence Foundation of China (Grant No. 52004040) .

语种：英文

外文关键词：CCUS; Minimum miscibility pressure; Shale reservoir; Confined space; Three-phase vapor-liquid-liquid equilibrium

摘要：The CO2 Enhanced Oil Recovery project offers an efficient method for extracting residue hydrocarbons after water flooding while achieving long-term CO2 sequestration. Recently, attention has turned to the potential of using shale formations, primarily exploited for unconventional oil and gas extraction, as CO2 storage sites. The technique of injecting CO2 in a miscible state enhances oil recovery while simultaneously sequestering CO2, with the minimum miscibility pressure (MMP) governing the displacement efficiency. However, the effectiveness of conventional MMP estimation methods is challenged by the unique properties of unconventional reservoirs, such as capillarity and nanopore confinement. Moreover, CO2 injection into shale reservoirs can induce the coexistence of three hydrocarbon phases under confined conditions, which further complicates MMP prediction. Consequently, there is currently no algorithm capable of accurately predicting the MMP for CCUS applications in shale reservoirs. This study introduces a novel MMP prediction algorithm incorporating both capillary pressure, confinement effect and three-hydrocarbon-phase displacements. The algorithm builds upon the modified MMC method and is enhanced by a three-phase vapor-liquid-liquid (VL1L2) equilibrium calculation framework that combines Newton-Raphson and trust-region methodologies. The proposed algorithm demonstrates robustness across various scenarios. It can be concluded from the results that when the VL1L2 three-phase region emerges, a pressure point with high oil displacement efficiency (PHp) is observed within this region, enabling CO2 flooding to achieve a higher oil displacement efficiency under lower pressures compared to the MMP. Compared to bulk fluids, the MMP for confined fluids can either decrease or increase, depending on the composition and critical properties of the oil samples. Conversely, the PHp increases across all tested oil samples.