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Study On The Extraction Of Micro Seismic Signal And Inversion Of Cracks In Hydraulic Fracturing

Posted on:2016-12-25Degree:MasterType:Thesis
Country:ChinaCandidate:Z C YuFull Text:PDF
GTID:2180330476951324Subject:Earth Exploration and Information Technology
Abstract/Summary:PDF Full Text Request
Hydraulic fracturing micro seismic technology through observation and analysis of micro seismic events can perform well in locating the cracks and the time of seismic occurrence, and monitor spatial distribution and geometry of cracks in the fracturing process.In this paper, research has been carried out from two aspects of micro seismic data processing; they were signal extraction and cracks inversion. Because in the actual seismic data, the signal-to-noise ratio is low by artificial picking and picking large amount of data is time-consuming and painstaking, still, it is difficult to meet the technical requirements of the microseismic eventsprocessing. Therefore, study of automatic picking and identification of micro seismic events is critical. In this paper, the signal is picked up by the instantaneous frequency method, the amplitude correlation method and the phase correlation method.(1) In the instantaneous frequency method, the wavelet and broadband wavelet were introduced to pick up and compared the picking effect, and contrasted the calculation results under different signal-to-noise ratio states.(2) The static correction, Superposition, Hilbert transform, envelope of the micro seismic data are carried out by amplitude correlation method, and identified the effective events, by using the method completed first arrival picking.(3) In the phase correlation method, through the calculation of the Fourier transform and inverse transform complete fingerprint, L ena image similar research. Phasecorrelation has been carried out on micro seismic signal under different noise to verify its noise immunity. Meanwhile, simulated annealing algorithm and genetic algorithm have been broughtinto the research of micro seismic source localization, optimizing inversion of the general function data and modeldata,comparing and analyzing these two methods before finally selected phase correlation method and simulated annealing algorithm in source localization of actual data.Through theoretical research and model study,comparing the applicability of different signal extraction methods and inversion methods, and gave suggestions to application of these methods in micro seismic localization and other geophysical prospecting.
Keywords/Search Tags:micro seismic monitoring, amplitude correlation, instantaneous frequency, phase correlation, simulated annealing algorithm, genetic algorithm
PDF Full Text Request
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