应用正交偶极子测井资料测量EDA地层的横波各向异性

MEASUREMENTS OF SHEAR-WAVE AZIMUTHALANISOTROPY WITH CROSS-DIPOLE LOGS

采用３种分析ＥＤＡ地层横波各向异性的技术处理了从ＷｙｏｍｉｎｇＰｏｗｄｅｒ河谷用正交偶极子测井取得的数据资料。这些处理技术基于挠曲波在各向异性介质中发生分裂的现象而模拟ＶＳＰ中的横波数据处理。四组分的正交偶极子测井数据是用Ｓｃｈｌｕｍｂｅｒｇｅｒ公司的测井仪从井深３５５０ｍ的一段长为５６ｍ的垂向裂缝发育的地层中采集的。根据对各发射－接收器组记录数据处理结果的一致性与方差来看，非正交旋转法效果最好。但线性变换法的结果也是可以接受的。线性变换法的优点是节省机时。从这组数据处理的结果来看，极化能谱法计算量相对较大并且对噪音的影响较敏感。

Three methods for analyzing azimuthal anisotropy from dipole logging data areexamined with the cross-dipole logging data from the Powder River Basin in Wyoming.These techniques are based on the phenomena of flexural wave splitting in anisotropicmaterials and simulate the techniques used for VSP data processing. The 4-componentcross-dipole logging data obtained with Schlumberger tool from a vertically fracturedsection of 56m at depth 3 550m are processed. The consistance and vanance of theresults from 6 transmitter-receiver pairs demonstrate that the non-orthogonal rotationmethod works best for the data. The results from linear transform method areacceptable. Among the 3 techniques, the linear transform processing takes the leastcomputing time. The polar energy spectrum method is computing intensive andrelatively more sensitive to noise.