Seismic S-wave modeling technology and its application in deep-water gas field reservoir prediction
Due to the lack of shear wave(S-wave)data in deep-water area,the P-wave model is generally con-verted to the S-wave model through linear relationship or phase control in the modeling process of pre-stack in-version.However,those methods may bring uncertainty due to human influence,and pre-stack inversion re-sults cannot fully and reliably represent the formation characteristics and reservoir distribution.Therefore,com-bining with the production demand,this paper proposes to extract Poisson's ratio information in three-dimen-sional space based on wide angle seismic data as the conversion relationship between P-wave and S-wave data,and then obtain the low-frequency model of S-wave constrained by Poisson's ratio.The specific steps are as follows:Firstly,the study evaluates the incident angle which is sensitive to the lithology in the formation.Secondly,the study extracts Poisson's ratio elastic impedance(PEI)with post-stack inversion based on far-angle seismic.Thirdly,the study converts the P-wave model into the S-wave model with the PEI.The explora-tion practice in the Baiyun deep-water area shows that pre-stack inversion results can clearly reflect the geologi-cal and lithologic information,and the plane distribution of No.2 sand body is consistent with the gas/water boundary and the real drilling results,which confirms the reservoir distribution,expands the proved natural gas reserves,and achieves good economic benefits.
pre-stack inversionP-wave modelS-wave modelPoisson's ratio elastic impedanceBaiyun deep-water area
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