涪陵页岩气田焦石坝地区含气量定量预测技术

页岩含气量是页岩气勘探选区和储层评价的一项重要指标。目前，利用地震资料对页岩含气性评价多停留在定性预测阶段，定量化表征方法尚不成熟。从已钻井的实测含气量出发，利用横波测井资料，分析实测含气量与地球物理参数之间的关系，利用数理统计学的思想，优选出密度、纵波阻抗、纵横波速度比、λρ 4个参数变量，建立了适合焦石坝页岩气田的含气量多元线性回归预测模型；通过叠前同时反演获得的密度、纵波阻抗等相关数据体，实现页岩含气量的定量预测，结果表明，预测的含气量与实钻结果吻合度较高，相对误差小，预测方法可靠；同时指出，焦石坝地区五峰组—龙马溪组一亚段含气量较高，为有利开发层段。

QUANTITATIVE PREDICTION TECHNIQUE FOR GAS CONTENT AND ITS APPLICATION TO JIAOSHIBA AREA OF FULING SHALE GASFIELD,SICHUAN BASIN

Gas content is an important index for evaluating resource potential of shale gas. Up to date, the seismic method has been adopted as the main tool for shale gas evaluation. However, it is mostly qualitative. There is so far no matured method for quantitative prediction of shale gas based on seismic data. Through the mathematical statistics of the core-measured gas content and other geophysical parameters, we selected 4 elastic parameters, namely the density, P-wave impedance, P-S wave velocity ratio and λρand established a multiple linear regression model suitable for the Jianshiba shale gas field. The density, P-wave impedance and other relevant elastic parameters are obtained through pre-stack simultaneous inversion. And quantitative prediction of gas content is made upon the results. The predicted and the measured values of gas content match well and have little errors. It is found out in this paper that the 1st Submember at the bottom of the Longmaxi Formation-Wufeng Fomation has higher gas content, and is the most favorable producing layer in the region.