Effective Estimation of Porosity and Fluid Saturation using Joint Inversion Result of Seismic and Electromagnetic Data

摘要

???? ??? ???? ??? ????? ??? ???? ???? ?????? ??????? ?? ????? ??? ??? ??? ??? ?????? ???? ?????? ???? ???? ??? ????. ???, ??? ??? ???? ??? ???? ????? ??? ??? ?????? ?? ????? ??? ????. ??? ??????? ??? ????? ?? ??????? ??? ??? ???, ??? ????? ?? ? ??, ? ????? ??? ?? ??? ? ?? ??? ????????? ??? ?? ????? ????? ??? ? ??. ? ????? ???? ???? ?????? ??? ???? ???, ???????? ??????? ????? ??? ??? ?? ??? ????? ??? ??? ?, ? ? ??? ?? ???? ??????? ???? ??? ?? ? ?????(grid-search)? ?????. ????? ??? ????? ??? ??, ?? ??? ?? ??? ???? ??????, ?? ?????? ??? ?? ?? ???, ??? ??? ?? ??? ??? ??? ? ??? ????.Petrophysical parameters such as porosity and fluid saturation which provide useful information for reservoir characterization could be estimated by rock physics model (RPM) using seismic velocity and resistivity. Therefore, accurate P-wave velocity and resistivity information have to be obtained for successful estimation of the petrophysical parameters. Compared with the individual inversion of electromagnetic (EM) or seismic data, the joint inversion using both EM and seismic data together can reduce the uncertainty and gives the opportunity to use the advantages of each data. Thus, more reliable petrophysical properties could be estimated through the joint inversion. In this paper, for the successful estimation of petrophysical parameters, we proposed an effective method which applies a grid-search method to find the porosity and fluid saturation. The relations of porosity and fluid saturation with P-wave velocity and resistivity were expressed by using RPM and the improved resistivity distribution used to this study was obtained by joint inversion of seismic and EM data. When the proposed method was applied to the synthetic data which were simulated for subsea reservoir exploration, reliable petrophysical parameters were obtained. The results indicate that the proposed method can be applied for detecting a reservoir and calculating the accurate oil and gas reserves.