基于偶极横波测井的地层各向异性研究

On Stratum Anisotropy Based on DSI Log Information

为确定塔中Ⅰ号断裂坡折构造带裂缝走向和水平主应力方位,利用偶极横波成像测井资料进行奥陶系碳酸盐岩储层各向异性研究。在分析偶极横波测井仪发射与接收信号特征的基础上,研究了横波分裂现象在裂缝性地层和构造应力不均衡地层中的响应特征。综合利用Alford旋转分析法与反演分析法提取了地层快、慢横波的慢度与方位,以此评价地层各向异性。参考FMI成像资料对塔中Ⅰ号断裂坡折构造带部分井奥陶系碳酸盐岩储层的各向异性进行了分析,研究认为快、慢横波在评价由裂缝和构造应力不均衡引起的地层各向异性中具有良好的应用效果。

Stratum anisotropy of carbonate reservoir in ordovician is analyzed with DSI log data so as to determine fracture orientation and main horizontal tectonic stress in Tarim I rupture depente structure belt. Studied are response characteristics of fission phenomenon of shear wave in fractured formation and imbalanced tectonic stress stratum based on analyzing transmitted and re- ceived signal characteristics of DSI logging tool. Slowness of both fast shear wave and slow shear wave as well as their positions are extracted by using Alford revolving analytic algorithm and inversion analytic method, from which we can evaluate the stratum anisotropy. Finally, the anisotropy of the reservoir in some wells in the belt is analyzed compared with that obtained from FMI log data. The practical log applications prove that the above method and principle are much better.