缝洞型油藏注气开发单元优选方法

A Preferred Method of Gas Injection Unit in the Fractured-vuggy Reservoir

针对目前缝洞型油藏采收率低、稳产困难等问题,开展注气开发物理模拟实验。考虑储层隔层、底水规模及连通性、注气压力恢复程度等对注气开发效果的影响,认识到储层无隔层,底水连通较好、规模较小,周期储层压力恢复程度较高时注气开发效果较好。推导注气开发的理论模型,编程分析注气后采收率大幅度提高,可以有效降低油井含水率。综合考虑剩余油量、水体规模及连通性、储层连通性、缝洞体积、油井钻遇/连通位置及油水界面位置等参数,给出注气开发单元优选原则,并进行实例分析。

Aiming at the problems that the recovery of fractured-vuggy reservoir is low and stable production is difficult, physical simulation experiments of gas injection development is carried out. The influence of reservoir compartment, the size of bottom water, connectivity and pressure recovery degree of gas injection on gas injection development are considered. The study result shows that the effect of gas injection development is better when reservoir is no interlayer, the connection of bottom water is better and the size is smaller, reservoir pressure recovery degree is higher. The theoretical model of the gas injection is derived. The result shows that the recovery is greatly improved and the water ratio of oil wells reduce effectively after gas injection. Considering the remaining oil in ground, the size of the bottom water and connectivity, reservoir connectivity, fracture-vuggy volume, oil well drilling or connecting position and the oil-water interface position, the selection principle of gas injection unit is given and an example is analyzed.