Borehole Fracturing Microseismic Monitoring Technology And Method Research

Microseismic monitoring, or say passive seismic monitoring, it is to point to usearrangement in water injection well around the detector, continuous recording for waterinjection fracturing, oil and gas recovery factors lead to underground rock cracking andproduce signals, thus monitoring reservoir fluid movement or hydraulic fracturing effect ofthe method. Micro seismic data signal to noise ratio (SNR) is low, all kinds of interferencedevelopment, microseismic data processing is well microseismic monitoring key problems.For micro seismic data processing method for micro seismic monitoring is very importantmeaning.First of all for microseismic data useful signal and noise characteristics, in theconventional energy than pick-up method research the suitable for borehole microseismic datausing the length of the time window energy ratio method, and the actual processing parameterselection, singular value processing details were studied. Through the model and actual dataprocessing show that the improved pick-up method in low signal noise ratio (SNR) still canget satisfactory results.Borehole microseismic random noise suppression is the key to deal with problems. Firstaccording to the borehole microseismic acquisition method, studies the basic principle ofconventional adaptive filter processing, introducing the constraint conditions that signalgradually become independent orthogonal direction evolution characteristics, from themethod design, parameters selection and other details have been studied in detail. Through theanalysis of actual data processing results prove the effectiveness of the proposed method.Studied the morphology filtering methods used in micro seismic data. By analyzing thestructure of the detail such as the size selection and combination of elements influence onfiltering result, obtained the parameters of the selection criteria. Through to the model andactual data processing of this method are compared with those of the median filtering, averagefiltering, shows that the method is based on the denoising don’t damage the advantages of effective signal.According to the characteristics of micro seismic data useful signal and noise are studiedfor the length of the borehole microseismic data using time window energy ratio method.Under the condition of low SNR in order to avoid the mistake found problems, according tothe multistage detector record events and cross-correlation signal the similarity of the research.And the actual treatment selection and singular values of the parameters in detail such asanalysed and studied.The calculation of the polarization direction is microseismic monitoring important link.The2D and3D situation hodograph analysis method. The weighted least-squares regressiontechnology can get polarization direction of the maximum likelihood estimation.According to the source inverse problem, and combining with actual microseismicthree-component records and data acquisition methods suitable for the characteristics of thestudied well microseismic data grid search algorithm. In the may trust domain, through thegrid search inversion to find the most addition, combined with the solution domain evaluationtechnology to work out the optimal solution, and at the same time, initial to use, accuracycontrol, inversion speed improvements are given to adapt to the microseismic characteristicsdescription algorithm through the theoretical and actual data calculation and proved to befeasible, more microseismic event joint inversion results show that the thesis based onforward modeling iterative inversion method, can effectively reflect the real position ofcracks.The model adopted by the trial and the actual data processing, can show that this paperstudies the borehole microseismic processing method can effectively solve the lowsignal-to-noise ratio (SNR) borehole microseismic data processing problems.