Methods Of Reservoir AVO Analysis Based On The Reformulated BISQ Mechanism

The actual oil and gas reservoirs medium is a multiphase porous media, the traditional interpretation techniques based on the amplitude of the single-phase medium model can not meet the need of the oil and gas seismic exploration any more. First, we have systematically investigated the two-phase porous media model, then focus and basis on reformulated BISQ mechanism, Finally we based on the reformulated BISQ theory of two phase medium interface AVO equation was deduced. Since the expression of BISQ-AVO equation parameters are too complex and it is difficult for application. We establish a paramters parameter method and series simplification method for BISQ-AVO equation and making the number of BISQ-AVO equation parameters and the expression of the form is simplified, It is convenient to practical application. In the two single-phase medium, BISQ-AVO equation can be reduced to conventional Zoeppritz equation. By further numerical simulation analysis, we found that the fast P-wave reflection coefficients used to calculate the overall higher than the single-phase medium AVO equation results. The result of transverse wave is relatively more complex. It explains that considering the medium pore, filling characteristics and solid-liquid coupling, AVO analysis in two-phase porous media and traditional AVO analysis results have a big difference. The parameters simplify has some effect on fast P-wave and S-wave reflection and transmission, but relatively small. However, it has a greater effect on the slow P-wave reflection and transmission; In the case of two series approximation, BISQ-AVO equation can function well in the range of 30-40 degrees and meet the needs of practical application.This research has important theoretical significance and application value for the interpretation of the fissures, oil and gas reservoir of sandstone-type seismic exploration amplitude.