数值模拟比值法计算水驱气藏体积波及系数

Calculation of volumetric sweep efficiency for water-drive gas reservoir based on numerical simulation ratio method

杨海¹ 李闽¹ 严东寅² 王刚³

西南石油大学油气藏地质与开发工程国家重点实验室，四川 成都 610500 中国石油塔里木油田公司开发事业部，新疆 库尔勒 841000 中国石油新疆油田公司井下作业公司，新疆 克拉玛依 834000

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Development Department, Tarim Oilfield Company, PetroChina, Korla 841000, China Downhole Operation Company, Xinjiang Oilfield Company, PetroChina, Karamay 834000, China

水驱气藏体积波及系数不仅可以反映当前的水驱体积波及情况，而且在确定气藏最终采收率中有着重要的地位，同时也是判断气田开发状况和调整效果的重要参数。文中在考虑地层流体及孔隙体积影响的前提下推导出了被波及网格含气饱和度上限值R的计算公式，并利用数值模拟的方法通过判定水侵前后网格含气饱和度的比值与R的差值来确定气藏被波及网格数，从而计算水驱气藏体积波及系数。该方法消除了在生产过程中流体及固体状态的变化对网格气体饱和度所带来的影响，并引用数值模拟实例来说明比值法的应用。

The volumetric sweep efficiency of water?鄄drive gas reservoir not only can reflect the current swept condition, but also can play a very important role in gas recovery calculation. Meanwhile, it can be applied to detect the production behaviors and check the stimulation operations. Considering the expansion of reservoir fluids and the decrease of pore volume, this paper derives the upper?-limited value of gas saturation R of swept blocks, which is used to calculate the difference between R and the ratio of gas saturation before water influx to gas saturation after influx. The difference is applied to determine the number of swept blocks of water-drive gas reservoir by which the volumetric sweep efficiency can be obtained. It is viable to eliminate the influence on the gas saturation which caused by the change of fluids and rocks. This paper takes the numerical simulation example to introduce the application of the ratio method.

10.6056/dkyqt201201024