异常高压气藏开发上的错误认识

针对气井的常规系统分析存在"用二项式等方法预测流入动态而不考虑气藏渗流特征"问题,提出了采用不稳态气藏渗流与井筒流动的耦合机制进行动态分析,充分考虑气藏的渗流特性、供给范围及开采过程中的地层压力递减情况.通过常规生产动态资料,确定气井的控制储量、地层参数,预测不同开采方式和不同时间情况下的气井产能和压力变化,评价可采储量及增压效果,从而优化气井的工作制度.异常高压气藏与正常压力气藏没有本质的区别,只是压力稍高而已.所有气藏的生产指示曲线都会向下弯曲,并非只有异常高压气藏才向下弯曲.异常高压气藏的生产指示曲线是一条光滑的曲线,而非折线形式.异常高压气藏的岩石压缩系数并非很高,而是与常规气藏一样,取很低的数值.异常高压气藏的岩石压缩系数与气藏埋藏深度无关,而与孔隙度和骨架硬度有关.

Misunderstanding the Performance of Abnormal Pressure Gas Reservoir

Abnormal pressure gas reservoirs are similar to normal pressure gas reservoirs, only the former is at higher pressure. The production index curves of all gas reservoirs, not only abnormal pressure ones, are curved downward. The production index curve of abnormal pressure gas reservoir is a smooth curve, not a tortuous line as conventionally plotted. Rock compressibility of abnormal pressure gas reservoir is similar to that of conventional reservoirs with a very small value. The rock compressibility of abnormal pressure gas reservoir is not related to the depth of reservoirs, but the porosity of reservoir rocks and the rigidity of rock frame.