Characteristics Analysis of Three-Component Wave Field Based on Borehole Microseismic Data of Shear Wave Splitting

The wave field data which is monitored the fracturing crack by micro seismic in the well is complex, especially when the shear wave (S-wave) encounters the fracture. The shear wave will split into the fast or slow wave. The polarization directions of the two kinds waves are perpendicular to each other. The identification of the shear wave field, the longitudinal wave (P-wave) field and fast or slow wave field, will directly affect the accuracy of the interpretation results. In order to improve the accuracy of interpretation results of microseismic data in wells, the wave field characteristics of waves in three-component geophone are analyzed according to the relationship between different incidence angles and the three components of the geophone, and it is concluded that the inversion results of the S-wave splitting event will cause fracture interpretation errors. Taking the micro-seismic fracture monitoring data of the Xinping XX well as an example, collect the micro-seismic records data of the P-wave, S-wave and fast/slow shear waves separately. Using the travel time inversion positioning algorithm of the first break collecting of the P/S waves, complete the micro-seismic positioning inversion of the P-wave+S-wave, fast S-wave +slow S-wave, P-wave+fast S-wave+slow S-wave fields. Through comparison, it is found that the orientation and distance of microseismic event localization results using only P-wave and S-wave are more reliable, and the fracture morphology is more consistent with the fracture growth law. At the same time, the influence of fast and slow S-wave on microseismic localization inversion results is fully explained.