摘要
流体在煤层中的传输机理由两部分组成 ,气体在煤内表面解吸 ,并通过基岩和微孔隙扩散进入裂缝网络中。若岩块表面甲烷气体的释放速度比气、水相在煤层割理中的流动速度快得多 ,那么在模拟煤层气开采过程时 ,解吸动能可以不考虑。根据这个假设可认为 :在给定压力下煤层吸附的甲烷气体量类似于相应压力下溶解在原油中的气体量 ;煤层中的朗格缪尔等温曲线可视为常规黑油油藏中的溶解气油比曲线。若将煤层表面的吸附气作为不流动油中溶解气来处理 ,那么可用常规黑油模型描述煤层气 ,而不需要对模型源码做任何修改。基于上述思路 ,用黑油模型模拟煤层气开采过程 ,并与用煤层气模拟软件 (COMETPC)的计算结果进行了比较 。
The transport of gas through a coal seam is generally considered a two-stage process. Gas desorption from the coal matrix followed by its flow along the fractures. If the release rate of gas from the matrix to the cleats is faster than the flow rate of gas and water in the cleats, the desorption kinetics are relatively less important in modelling coalbed methane production. Under this assumption, the gas held by the coal is similar to that dissolved in the black oil at a given pressure. The solution gas-oil ratio of this immobile oil is calculated from the Langmuir adsorption isotherm curve. A conventional black oil simulator can be used to simulate coalbed gas reservoir by treating gas adsorbed to the surface of coal block as gas dissolved in the immobile oil. Based on the ideas above, a coalbed methane reservoir has been studied by using black oil simulator, and the results are very close to those from a coalbed methane reservoir simulator(COMETPC).
出处
《西南石油学院学报》
CSCD
2001年第5期26-28,共3页
Journal of Southwest Petroleum Institute
基金
"油气藏地质及开发工程"国家重点实验室开放基金项目 (PLN0 111)
