Qi Chuangchuang, Haroun Mohamed, Rahman Md Motiur, Suboyin Abhijith, Abubacker Ponnambathayil Jassim, Ghosh Bisweswar
Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates.
ACS Omega. 2023 Jun 27;8(27):24426-24440. doi: 10.1021/acsomega.3c01984. eCollection 2023 Jul 11.
A polymer flooding workflow was developed to diminish polymer degradation and minimize formation damage under high-temperature-high-salinity reservoir conditions by using a shear-thickening polymer (SAP) prepared in engineered waters. First, rock characterization, fluid-fluid analysis, and formation damage tests were conducted to shortlist the potential formulations of polymer solutions based on higher viscosity and less formation damage. Second, polymer core flooding experiments were conducted under reservoir conditions to investigate the performance of candidate polymer solutions on oil displacement efficiency (DE). For the first time, the compatibility between SAP and engineered water was systematically tested. The factors affecting bulk rheology, polymer retention, and oil DE, including polymer concentration, polymer type, salinity, and hardness, were experimentally investigated and compared with regular partially hydrolyzed polyacrylamide (HPAM). Results showed that compared with HPAM, the SAP solution led to lower formation damage and overall higher oil DE, especially in the first 0.4 pore volume of polymer injection. When using SAP prepared in twice-diluted and hardness-stripped seawater under low-salinity formation brine conditions, the DE was the highest (69.04%). The formation damage was reduced when the salinity and hardness of the base fluid were lower, whereas stripping the hardness had a more pronounced effect on reducing formation damage. The improved oil recovery potential due to the shear-thickening feature of SAP solutions and their better compatibility with engineered water compared to regular HPAM has been proven in this study. It was also found that the lower salinity and hardness of the engineered water further stimulated the enhanced oil recovery potential of SAP solutions. The contribution of this work relies on revealing how SAP prepared in different engineered waters affects incremental oil DE under harsh reservoir conditions based on experimental evidence and mechanism analysis. The novelty of this work lays the foundation for investigating the potential application of SAP on a pilot scale.
通过使用在工程水中制备的剪切增稠聚合物（SAP），开发了一种聚合物驱油工作流程，以减少聚合物降解，并在高温高盐油藏条件下使地层损害最小化。首先，进行岩石特性分析、流体-流体分析和地层损害测试，以基于更高的粘度和更低的地层损害筛选聚合物溶液的潜在配方。其次，在油藏条件下进行聚合物岩心驱油实验，以研究候选聚合物溶液对驱油效率（DE）的性能。首次系统测试了SAP与工程水之间的兼容性。通过实验研究了影响本体流变学、聚合物滞留和油相DE的因素，包括聚合物浓度、聚合物类型、盐度和硬度，并与常规部分水解聚丙烯酰胺（HPAM）进行了比较。结果表明，与HPAM相比，SAP溶液导致更低的地层损害和总体更高的油相DE，尤其是在聚合物注入的前0.4孔隙体积内。在低盐度地层盐水条件下使用在两倍稀释和去除硬度的海水中制备的SAP时，驱油效率最高（69.04%）。当基础流体的盐度和硬度较低时，地层损害会降低，而去除硬度对减少地层损害有更显著的影响。本研究证明了由于SAP溶液的剪切增稠特性及其与工程水相比与常规HPAM更好的兼容性，其具有提高采收率的潜力。还发现工程水的低盐度和低硬度进一步激发了SAP溶液提高采收率的潜力。这项工作的贡献在于基于实验证据和机理分析揭示了在不同工程水中制备的SAP如何在恶劣油藏条件下影响增量油相DE。这项工作的新颖性为研究SAP在中试规模上的潜在应用奠定了基础。
