Location of Microearthquakes Sources at Passive Seismic Monitoring of Hydraulic Fracturing

摘要

The paper discusses microseismic monitoring during oil well stimulation by hydraulic fracturing, an emergent technology used for hydraulic fracturing layer control. The passive monitoring is a new widely developing technology of HFL control. The main factor affecting the results of passive seismic monitoring is the event location accuracy. The passive monitoring acquisition system utilizes one three components seismic probe deployed into the observation well. To evaluate the location accuracy of induced events for one observation well we applied traditional kinematic approach based on picking of earthquake P- and S-waves arrivals. The influence of geometric parameters of geophones location in a borehole, their quantity, picking errors of waves arrivals on the accuracy of microearthquakes location is studied.rnA new method based on dynamic event location using observations in one borehole is proposed and realized. Examples of realization of the new method of location on synthetic examples for isotropic and anisotropic media for P- and S-waves are given. The method was also tested on real data with the known earlier source location (perforation effect prior HFL). The method allows us to automate a process of microseismic data processing at the hydraulic fracturing and increase reliability of results of passive monitoring.