X oilfield is a typical sandstone reservoir with big bottom water in the Bohai Sea. The viscosity of crude oil ranges from 30 to 425 cp. Single sand development with the horizontal well is adopted. At present, the water content is as high as 96%. The water cut of the production well is stable for a long time in the high water cut period. The recoverable reserves calculated by conventional methods have gradually increased, and even the partial recovery has exceeded the predicted recovery rate. This study carried out an oil displacement efficiency experiment under big water drive multiple to accurately understand an extensive bottom water reservoir's production law in an ultra-high water cut stage. It comprehensively used the scanning electron microscope date, casting thin section, oil displacement experiment, and production performance to analyze the change law of physical properties and relative permeability curve from the aspects of reservoir clay minerals, median particle size, pore distribution, and pore throat characteristics. Therefore, the development law of horizontal production wells in sandstone reservoirs with big bottom water is understood. It evaluates the ultimate recovery of sandstone reservoirs with big bottom water. It provides a fundamental theoretical basis and guidance for dynamic prediction and delicate potential tapping of sandstone reservoirs with big bottom water at a high water cut stage.

X油田是渤海典型的大底水砂岩油藏。原油的粘度范围为 30 至 425 cp。采用水平井单砂开发。目前含水量高达96%。生产井在高含水期含水长期稳定。常规方法计算的可采储量逐渐增加，甚至部分采收率超过了预测采收率。本研究开展了大水驱倍数下的驱油效率实验，以准确了解特高含水期粗放型底水油藏的生产规律。综合利用扫描电镜数据、铸件薄片、驱油实验、从储层粘土矿物、中值粒径、孔隙分布、孔喉特征等方面分析物性和相对渗透率曲线的变化规律。因此，了解大底水砂岩油藏水平生产井的开发规律。评价大底水砂岩储层的最终采收率。为高含水期大底水砂岩储层动态预测和精细挖潜提供了基础理论依据和指导。了解大底水砂岩油藏水平生产井的开发规律。评价大底水砂岩储层的最终采收率。为高含水期大底水砂岩储层动态预测和精细挖潜提供了基础理论依据和指导。了解大底水砂岩油藏水平生产井的开发规律。评价大底水砂岩储层的最终采收率。为高含水期大底水砂岩储层动态预测和精细挖潜提供了基础理论依据和指导。