一种提高独立封闭有水气藏储量计算精度的新方法

NEW METHOD TO IMPROVE CALCULATING ACCURACY OF SEPARATE CLOSED AQUIFER GAS RESERVOIRS

物质平衡法是气藏储量计算中用得最多、计算较为准确的一种方法。对于独立封闭有水气藏而言 ,应用物质平衡法时一般不考虑水和岩层的弹性能 ,储量计算结果总是在随着开发程度的提高而不断变化 ,没有一个定值 ,给气藏中后期开发工作带来了一定的难度。文章对物质平衡法加以改进 ,将地层水和岩石骨架的形变及上覆岩石的压实作用作为气藏空间的影响因素考虑进去 ,应用曲线拟合法求解 ,可以大大提高处于开发中后期的独立封闭有水气藏储量计算精度 ,赤水气田旺 8井的实践证明了这点。

Material balance method is most used in reserve calculation of gas reservoirs, and its calculating results are accurate relatively. As for separate closed aquifer gas reservoirs, the reserve calculating results always change along with the development progress since the elastic energy of water and rock is not considered usually when material balance method is used. So, the reserve calculating results are not deterministic, which brings difficulty to the late development of gas reservoirs. The article makes a little modification to the material balance method, considers the influence of the deformation of formation water and rock matrix and the compaction of overburden on the room of the gas reservoirs, and applies the curve fitting method for solution. Thus, the reserve calculating accuracy of separate closed aquifer gas reservoirs can be improved greatly for their late development. The real case of well Wang 8 in Chishui gas field proves it.