The Approach Of Micro-seismic Location

Micro-seismic technology is derived from natural earthquake prediction, widely usedin mining fields, and rapidly developed in the petroleum industry. Micro-seismicmonitoring technology is a reliable solution for safety hazard identification ofcoalfield and mine development. As the state of unconventional oil and gasexploration and development efforts continue to increase, and hydraulic fracturingtechnology matures, micro-seismic monitoring has become an important means ofassessing the effects of fracturing.A rapid method for two-point ray tracing in horizontally layered velocity model ispresented in this paper. This method can effectively solve the convergence problem ofbig incident angle in level layer velocity model.Relative to other similar methods, thecalculation efficiency and calculation accuracy is improved. To effectively avoid thefailure to identify micro-seismic events on a single component due to the principle offocal mechanisms and polarization caused no amplitude response,Using the signals ofthe three components of the micro-seismic events on the identification process;Through amplifying the energy difference ratio, choosing energy ratio of differentsizes can effectively identify different energy intensity fracturing micro seismicevents; Through real-time computing the energy ratio of vertical component andradial component, wellbore wave noise from the ground and wells can be effectivelyidentified.By using down-hole micro seismic records rotation, detector orientation, velocitymodel calibration methods shear wave polarization angle，The dissertation propose themicro-seismic event location method based on energy grid search of the diffractionstack. The method has worked well on synthetic and real data tests.A processing flow has been designed in the dissertation to process micro-seismicevent location for real-time monitoring, and applied to the actual process ofmicro-seismic data, and achieved good results, It proves that data processing flow canbe applied to on-site real-time location. Such processing flow method based on thecombination of forward ray tracing and inversion is introduced, making the eventlocation is fully automated and improved signal to noise ratio for low ability toidentify and locate.