强底水砂岩油藏大排量生产后期挖潜方式研究

Study on the Method of Tapping Potential in Later Stage of Large Displacement Production in Marine Strong Bottom Water Sandstone Reservoir

针对海相砂岩FOURD油藏大排量生产,发现底水油藏开发过程中不同位置水驱孔隙体积倍数不同,而常规行标中测量的实验不足以表现高水驱倍数后的油藏渗流特征。高水驱实验结果表明,不同黏土含量岩心水驱倍数的半对数与驱油效率呈线性关系,底水油藏水驱波及系数缓慢增加。基于FOURD油藏实际资料,采用数值模拟技术表征了油藏时变特征;针对FOURD油藏南北动态不同、南区水淹程度高、波及程度难以提高的问题,提出了以提液方式再提升油藏驱油效率的方案,针对北区波及程度不高的区域提出了进行井网加密的后期挖潜方案。采用该极限挖潜策略后,根据数值模拟及实际矿场应用,波及系数提高了11.1%,标定采收率提高了4.5%。

In view of the large displacement production of marine sandstone FOURD reservoir, it is found that the water drive pore volume multiples at different locations are different during the development process of bottom water reservoir, while the experiments measured in the conventional industry standard are insufficient to express the seepage characteristics of the reservoir after the high flooding multiple. The high-power water drive experiment shows that the half logarithm of core displacement multiples with different clay content has a linear relationship with oil displacement efficiency, and the water drive sweep volume of bottom water reservoir increased slowly. Based on the actual data of FOURD reservoir, the time-varying characteristics of the reservoir were characterized and studied by numerical simulation technology. According to the different north-south dynamics of FOURD reservoir, the water flooding degree in the south area is high and the sweep degree is difficult to improve. The oil displacement efficiency of the reservoir is improved by liquid extraction, and in the north area and where the impact degree is not high, the later potential tapping mode of well network encryption is adopted. After adopting the limit tapping potential strategy described in this paper, according to the results of numerical simulation and practical mine application, the swept volume increased by 11.1%, and the calibration recovery increased by 4.5%.