基于测井推演的岩石力学参数识别致密砂岩气层

An Identification Method Based on Rock Mechanics Parameters Logging Deduction to Tight Sandstone Gas Reservoirs

苏里格气田致密微裂缝性碎屑岩储层具有孔隙度低、渗透性差、孔隙结构复杂等特点,利用常规测井资料难以对储层含气性进行有效评价。通过对声波在岩石中传播特性和流体声学特征分析发现,地层在高含气饱和度情况下,其纵波、横波速度和压缩系数及泊松比等参数的变化明显不同于差气层、水层、干层。利用偶极声波测井资料中的纵横波时差曲线和常规的DEN、GR曲线能快速准确地计算地层的各种岩石力学参数,尤其是泊松比、体积压缩系数与流体体积压缩系数等,并采用交会图法或曲线重叠法可以直观有效地识别气层。该方法可明显提高致密砂岩气层的识别符合率,实用性强,对新区块新层系的试采和压裂改造选层有着重要的指导意义。

Micro-fractured tight clastic reservoir has low porosity and poor permeability, complex pore structure and other characteristics in Sulige gas reservoirs, it is difficult to use conventional logging data for effective gas-bearing reservoir evaluation. Based on acoustic propagation in the rock and fluid acoustic feature analysis, we found that the formation with high gas saturation in the case of the longitudinal wave, shear wave velocity and compression factor and Poisson＇s ratio and other parameters change markedly from poor gas, the water layer and dry layer. With the S- wave slowness and regular DEN, GR curves of DSI logging data, we can quickly and accurately calculate the various strata rock mechanics parameters, especially the Poisson＇s ratio, volume compressibility coefficient of volume compressibility and the fluid volume compressibility coefficient of volume compressibility, etc, and the cross-plot method or curves overlap method can effectively identify visually gas. The results show that this method can significantly improve the identification of tight sandstone gas reservoirs compliance rate and is practical in new formations identification of test mining and fracturing layers.