The Seismic Phase Separation Of The Microseismic Signal

The characteristic of the microseismic signal gathered in field is that its center of origin unknown, the energy is weak, the signal-to-noise ratio is low, and the direction of wave arrival is randomness, above which examine to separate and recognize wave shape monitored by the geophone in vertical component and the horizontal component recording much more difference.For this reason, this article studies the fundamental principle of the microseismic monitoring firstly, analyzes the stimulation principle of the microseism monitor in theory and masters the basic characteristic of the microseismic signal. In view of position randomness of the three component detector component in well, this article uses the perforation recording to carry on the horizontal component localization of the detector. In view of the wave direction of arrival randomness examined in each component, the article traces the wave tracking component with utilizing wave first kind of directional characteristic and the second kind of directional characteristic comprehensively to carry on the phase separation, through researching the seismic phase separation technology based on the polarization-position comparison method. When use polarization comparison to trace wave track component, this article is started with the most general polarization filtering firstly, and then studies auto-adapted polarization filtering method which is in view of the complex wave field.When process wave position contrast using the wave second kind of directional characteristic to trace the wave, this article studies the frequency coherence filtering and the two-dimensional narrow pass band filter of changed speed.When use wave polarization-position comparison union to choose the wave tracking component, this article has studied two polarization-position comparison methods. Namel: the polarization filtering which has the assigned polarization parameter combine frequency coherence filtering and the auto-adapted polarization filtering unifie improvement two-dimensional narrow pass band filter.With the filtering algorithm design in frequency coherence, we propose algorithm of circle with left and right coherence degree to attain the aim of pressing noise and heighting the valid signal. The conventional polarization filtering which took the fixed component as expectation direction to obtain the surplus section plane, and then puts together can also may the sketchy synthesis microseismic signal track component, achieve the goal of the phase separation.In view of existence question using the conventional two-dimensional filtering in processing microseismic data, this article has designed the improvement two-dimensional narrow pass band filter. Namely: counting the coefficient of correlation in each aperture, confirming the signal speed range in each aperture, and then use the window expansion technology to remove the alias and divulging which is created by the two-dimensional fft transformation. When designs the auto-adapted polarization filtering, searching each wave's expectation direction(also is tracks component direction) which search the direction based counting the near the polarization projection correlation biggest projection.And then structures the polarization filtering factor to carry on the auto-polarization filtering which to choose wave. After, three component microseismic recording filtered are projected to the expectation direction separately, plan comprehensive seismic record of the tracking component and then achieving the microseismic signal phase separation. And recognize each king of mcroseismic signal.The application example and the model result in the article indicated that: the polarization-position correlation method phase separation technology based the improvement two-dimensional narrow pass band filter-auto-adapted polarization filtering unified, which can use the wave two kind of directional characteristic fully and reduce the distortion of the amplitude. In the tracking component synthesis seismic record, each kind of microseismic signal phase can be separated clearly...