Application of Geostatistical Inversion in Sand Prediction in 128 Block,Xinmu Oil-field
Wei Wang · Science Technology and Engineering · 2012
With the constrained sparse pulse inversion results as the background constrained,high resolution of spontaneous potential geo-statistic inversion was launched.First,with histogram and variogram analysis,the spontaneous potential change process in different directions was determined.Second,in every seismic trace,in order to get synthetic seismic trace,reflection coefficient and seismic wavelet were extracted randomly into deconvolution.Then generating synthetic seismic trace was matched with the original seismic trace,to calculate inversion residuals,until meeting precision requirements.Four random inversion results was gained for RMS operations,to get the final inversion results.Finally,by setting the threshold value of sand shale,lithologic data extraction and sandstone velocity field establishment,mathematical function is used to get the rock body in depth domain and sandstone distribution in map of 5 sand group.With these process,the sand body quantitive predicting was realized.The result show that the relative error of 95% post-test well sandstone thickness is less than 10%.Therefore it can provide an effective basis of drilling and strata exploration decision-making.