There are multiple combinations of sandstone and mudstone interbeds and also plenty of coal seams in the middle-shallow strata of Mahu sag's slope zone, due to the slow slope background and shallow lake environment of water oscillation since Jurassic. In addition, the lithologic reservoir can be found in the zone, but the shielding effect of coal seam makes it impossible to predict the reservoir, due to the unclear response of the thin interbed from seismic and acoustic logs. Therefore, the wave impedance inversion cannot distinguish sandstone from mudstone clearly. In view of such a situation, the technique of Pseudo-acoustic curve reconstruction was used in this study. By analyzing multiple well logs, the density and neutron curves, which can weaken the influence of coal seam and reflect the characteristics of sandstone and mudstone interbeds, were selected to rebuild pseudo-acoustic curves and then perform inversion with the rebuilt curves, thus improving greatly the accuracy of reservoir prediction.
Chen D Y, Zhang B W, Yue H Y , et al. The application of geostatistical inversion based on characteristic curve structuring technology to thin sand body reservoir prediction[J]. Geophysical and Geochemical Exploration, 2018,42(5):999-1005.
Bosc H M, Mukfrji T, Gonzalez F F . Seismic inversion for reservoir properties combining statistical rock physics and geostatistics: a review[J]. Geophysics, 2010,75(5):A165-A176.
She G, Zhou X Y, Wang J B . Prediction of sand reservoir with multi-wavelet seismic trace decomposition and reconstruction[J]. Journal of Southwest Petroleum University:Science & Technology Edition, 2013,35(1):19-27.
Liu Y H, Huang D W, Duan D P , et al. Application of seismic sedimentology to the prediction of middle-deep sand body in coal-bearing isochronous stratigraphic framework[J]. Acta Sedimentologica Sinica, 2018,36(5):957-968.
Lu Z Y, Ma S Z, Fei F X , et al. Analysis on fan-delta front depositional facies and its effect on single well productivity—take Baikouquan Formation of well M18 for example in Mahu Sag[J]. Henan Sciences, 2018,36(8):1256-1261.