【摘要】 微地震检测的关键是确定微震源的位置。本文讨论了利用井下多级三分量检波器资料反演微震源位置的新方法。首先用射孔直达纵波水平分量确定检波器的方位角;再在三维空间逐点对检波器组计算直达波旅行时并通过沿直达纵波时距曲线进行能量叠加,反演得到微地震震源位置的分布范围;针对微震源反演存在的多解性问题,利用微地震直达纵波水平检波器分量变换和震—检地理方位角的关系确定微震源的方位角;最后采用两种空间点集的统计方法确定微震源点的位置坐标。在均匀介质、斜井直线观测系统的三分量微地震正演模拟记录上所作的微震源反演试验表明,在信噪比较低的情况下,利用这些方法可以有效与稳定地反演微震源的位置。更多还原

【Abstract】 The key of micro-seismic monitoring study is to decide micro-source location.We propose here a new method to inverse micro-source location using VSP multi-level three component data.Firstly the orientation angle of horizontal geophones is decided by horizontal components of direct compress wave generated from perforation.Then by calculating travel time of direct compress wave from every geophone point in 3Dspace and stacking energy along T-X curve of direct wave,micro-source distribution range is inversed.After that,a horizontal component conversion of microseismic direct compress wave and a source-receiver geography azimuth are used to determine micro-source azimuth.This is to reduce multi-solutions occurred in microsource inversion.Finally two statistic methods for space points are introduced to confirm the microsource location.A test on micro-seismic synthetic data of homogeneous medium with an inclined well and line geometry shows that micro-source location can be inversed accurately and steady by the new method even with low S/N synthetic data.更多还原