横波各向异性在裂缝和应力分析中的应用

针对裂缝性和低孔低渗地层的横波各向异性特征,反演得到横波各向异性参数,研究了裂缝的发育程度、方位和有效性,并对低孔低渗地层的应力场分布状态和方位进行了综合评价;通过对反演得到的快、慢弯曲波形进行频散分析以及计算单极横波各向异性大小,确定了引起横波各向异性的原因,并结合常规测井资料、岩心及FMI成像资料对分析结果进行了验证和对比,最后对研究区8口典型井的横波各向异性进行了综合处理和评价,得到了该区的横波各向异性特征以及和总的应力场走向.结果表明,利用横波的各向异性参数可以有效的评价裂缝的发育程度、走向及有效性,并能准确的确定地应力分布状态和最大水平应力方位.

Application of shear wave anisotropy in fractures and in-situ stress analysis

In the light of shear wave anisotropy of fractures and low porosity and low permeability formation characteristics.And then according to those inversion parameters we study development degree of fractures,orientation and effectiveness,and evaluate comprehensively the in-situ stress field distribution and orientation of low porosity and low permeability strata;And the paper analyze the reason of shear wave anisotropy caused by extracting dispersion curve of the fast and slow flexural waveform and calculating shear wave anisotropy monopole waveform,afterwards the analysis results are verified and compared with the well-logging data,cores and FMI image data of study area.At last,we process and evaluate comprehensively shear wave anisotropy of 8 typical wells in the target area,thus obtain shear wave anisotropy characteristics and total stress field orientation.The results show that shear wave anisotropy parameters can be used to effectively evaluate development degree of fractures,orientation and effectiveness of fractures,and can accurately pinpoint an in-situ stress state and the maximum level stress orientation.