Elimination of high-amplitude noise during passive monitoring of hydrocarbon deposits by the emission tomography method

Abstract

Emission tomography used in passive seismic monitoring of hydrocarbon deposits enables regular inspection of development of hydraulic fracturing and relaxation processes in volumes of fracturing, tracing of fluid migration paths, redistribution of stresses due to field development accompanied by seismic emission from volumes of structural defects and stress concentration, and localization of fractured and faulted structures from emission and scattering data. Intensive man-made seismic noise in the areas of oil field development produces a strong screening effect in identification of weak deep seismic sources. On the basis of experiments with simulated and real data of surface seismic arrays in regions of oil deposits in Western Siberia (carried out in the framework of the passive monitoring program of the SYNAPSE Science Center), it is shown that the use of algorithms of adaptive optimal and rejection spatial filtering with the estimation of the spectral density matrix of multichannel observations in the framework of multivariate autoregressive-moving average modeling is effective for eliminating the influence of anthropogenic noise and revealing (in oil production areas) both deep seismic sources supposedly active in scattering regions of the lower part of the sedimentary cover and the crystalline basement. The projection of the scattering regions onto the horizontal plane correlates well with the position of faults in the area of in situ observations.