Micro-seismic Monitoring System And Ground Source Localization Method Of Hydraulic Fracturing

Microseismic monitoring technology has become an important method of Fracture Evaluation induced by hydraulic stimulation of oil and gas wells. By deploying geophones in borehole or on surface, microseismic signals induced by hydraulic fracturing can be received. A series of3Dcoordinates can be calculated by detennining the source locations of those microseismic events, and the parameters of induced fractures can be determined by the distribution of event points, also dynamic evolution process of fractures can be described by the distribution of event points via time. This technology is low cost with simple construction conditions, no harm to the wellbore and imaging results, and the results is of great significance for the understanding of the law of crack propagation, and guiding the optimization of fracture designA single channel ground micro seismic data recorder with high performance was developed in the thesis firstly. It’s designed by China University of Petroleum (East China), Institute of Petroleum Resources and Environmental Geology.A Cirrus geophysical surveys chip was selected to amplify the signal and realize A/D conversion and digital filtering; The universal time and GPS coordination was gat by GPS chip; U disks were installed at every monitor site to collect and store data. Then P-wave method and SET(Seismic Transmission Tomography) were proposed to determinate the artificial hypocenter. To compare the effects of these two methods, the simulation signal polluted by white noise with different standard deviation were tested. The results showed that P-wave method requires high signal-to-noise ratio, difficultly observes the beginning time of seismic wave, and is highly affected by human factors. By contrast, the SET can accurately determine the hypocenter when the signal-to-noise ratio is lower than a specific threshold. Finally, the microseismic data recorder and SET method were applied in the F well and W well to monitor microseismic and determine hypocenter during the fracturing procedure. Theoretical research and field application has proved that the design of the microseismic data recorder is reasonable, the effect of the SET method used for oil and gas wells fracture monitoring is good.