The Study And Application Of Pseudo Multi-channel Matching Cross-Equalization Method In Time-lapse Seismic Data

Time-lapse seismic analysis is critical to evaluate reservoir production efficiency and potential after exploitation.The rock pressure,porosity and density and other physical properties had changed after production,which induced the variations of seismic response.These changes are the goal for seismic analysis,but they tend to be disturbed by other reasons.The main factors affeting the repeatability of time-lapse seismic data is the observation system.Because they the have different goal,task in different stages.The residual differences on calibrated seismic section still exist.So uniformity processing between time-lapse seismic data is the key for successful time-lapse seismic analysis.And one important part of uniformity data processing is cross-equalization.The traditional approach of cross-equalization methods are amplitude balancing,time correction,phase correction,and single channel matching filter method which correct poststack seismic data.This method is relatively easy to implement,but can not completely eliminate differences in non-reservoir areas.Useing the pseudomultichannel matching method on seismic data in the cross-equalization processing flow to remove the non-reservor difference more thoroughly.In this paper we simulate the velocity models before and after fluid replacement based on Gassmann equation.Then We also analyzed several kinds of repetitive standards to monitor and guide the cross-equalization processing flow.Conversely,NRMS is extremely sensitive to the smallest of changes in the data.Inversely PRED is insensitive to amplitue of seismic data.The metrics of NRMS and PRED alone do not lead to an intuitive understanding of the data repeatability,and they require interpretation of their values.The third metrics is correlation parameters which directly isolated data informations more intuitively.At last,we used the synthetic case and field data case,difference sections between the original monitor data sets and matching data sets after each step of the cross-equalization processing flow show a progressive reduction of non-reservoir difference and a improvement in time-lapse reservoir information.Pseudo-multichannel matching method can better eliminate the differences in nonreservoir.