P波资料反演裂缝方法及实例

Fracture inversion using P-wave reflection data and cases.

本文根据 Grechka和 Tsvankin(1998)导出的非均匀各向异性介质与 NMO速度的方向关系式 ,对介质裂缝进行了预测。首先 ,在实验室进行了模型观测 ,观测结果表明在裂隙介质层上方的 NMO速度方位变化呈椭圆状 ,长轴方向代表裂隙走向 ,长短轴之比正比于裂隙发育密度。然后 ,将本文方法应用于塔里木盆地北部 A区有限方位的三维地震资料中 ,所预测的裂隙发育带展布方位与成像测井揭示的结果一致 ,取得了较好的应用效果。这表明用本文方法识别裂缝方向和密度是可行的。

According to directional relation of NMO velocity in heterogeneous anisotropic m edia deduced by Grechka and Tsavankin,the paper predicted the fracture of media.Fist,the model observation in laboratory is carried o ut,which results showed the orientation variation of NMO velocity above the fr actured media is ellipse,the direction of major axis represents the trends o f racture,the ratio of major and minor axes is proportion to the developed densi ty of fracture.The method is used for limited azimuth 3-D seismic data in A wo rk area of northern Tarim basin,the predicted fracture orientation is coincide d with the results revealed by logging data,which achieved good applied results .This showed the feasibility of the method in identification of fractured dire ction and density.