Sagandykova Dilyara, Shakeel Mariam, Pourafshary Peyman
School of Mining and Geosciences, Nazarbayev University, Astana 010000, Kazakhstan.
Polymers (Basel). 2024 Jun 11;16(12):1651. doi: 10.3390/polym16121651.
The application of polymer flooding is currently under investigation to control water cut and recover residual oil from a giant sandstone reservoir in Kazakhstan, where the water cut in most producers exceeds 90%, leaving substantial untouched oil in the porous media. The primary objective of this research is to explore the feasibility of a novel approach that combines the mechanisms of mobility control by polymer injection and the thermal effects, such as oil viscosity reduction, by utilizing hot water to prepare the polymer solution. This innovative hybrid method's impact on parameters like oil recovery, resistance factor, and mobility was measured and analyzed. The research involved an oil displacement study conducted by injecting a hot polymer at a temperature of 85 °C, which is higher than the reservoir temperature. Incremental recovery achieved through hot polymer injection was then compared to the recovery by conventional polymer flooding and the conventional surfactant-polymer-enhanced oil recovery techniques. The governing mechanisms behind recovery, including reductions in oil viscosity, alterations in polymer rheology, and effective mobility control, were systematically studied to comprehend the influence of this proposed approach on sweep efficiency. Given the substantial volume of residual oil within the studied reservoir, the primary objective is to improve the sweep efficiency as much as possible. Conventional polymer flooding demonstrated a moderate incremental oil recovery rate of approximately 48%. However, with the implementation of the new hybrid method, the recovery rate increased to more than 52%, reflecting a 4% improvement. Despite the polymer's lower viscosity during hot polymer flooding, which was observed by the lower pressure drop in contrast to the conventional polymer flooding scenario, the recovery factor was higher. This discrepancy indicates that while polymer viscosity decreases, the activation of other oil displacement mechanisms contributes to higher oil production. Applying hybrid enhanced oil recovery mechanisms presents an opportunity to reduce project costs. For instance, achieving comparable results with lower chemical concentrations is of practical significance. The potential impact of this work on enhancing the profitability of chemically enhanced oil recovery within the sandstone reservoir under study is critical.
目前正在研究聚合物驱油技术在哈萨克斯坦一个巨型砂岩油藏中的应用，以控制含水率并采出残余油。该油藏大多数生产井的含水率超过90%，多孔介质中仍有大量未采出的原油。本研究的主要目的是探索一种新方法的可行性，该方法结合了聚合物注入控制流度的机理和热效应，例如利用热水配制聚合物溶液来降低原油粘度。测量并分析了这种创新的混合方法对采收率、阻力系数和流度等参数的影响。该研究包括一项驱油实验，通过注入85℃的热聚合物进行驱油，该温度高于油藏温度。然后将热聚合物注入实现的增量采收率与常规聚合物驱油以及常规表面活性剂 - 聚合物强化采油技术的采收率进行比较。系统研究了采收背后的控制机理，包括原油粘度降低、聚合物流变学变化以及有效的流度控制，以理解该方法对波及效率的影响。鉴于所研究油藏中残余油的大量存在，主要目标是尽可能提高波及效率。常规聚合物驱油显示出约48%的适度增量采收率。然而，采用新的混合方法后，采收率提高到了52%以上，提高了4%。尽管在热聚合物驱油过程中观察到聚合物粘度较低，与常规聚合物驱油情况相比压降较低，但采收率更高。这种差异表明，虽然聚合物粘度降低，但其他驱油机理的激活有助于提高原油产量。应用混合强化采油机理为降低项目成本提供了机会。例如，以较低的化学剂浓度取得可比结果具有实际意义。这项工作对提高所研究砂岩油藏中化学强化采油的盈利能力的潜在影响至关重要。
