Application of Extrapolation Inversion Controlled by Seismic Facies in Predicting Deep Lithologic Hydrocarbon Reservoirs in Tarim Basin of Western China

The lithologic or structural-lithologic reservoirs is widly distributed in the continental and transitional sedimentary environments. Due to the exploration of traditional structural reservoirs is almost out, the exploration of lithologic reservoir is increasingly significant. Nevertheless, the characterization of such kind reservoirs is exceedingly difficult because of large buried depth, thin thickness of layer, strong stealthiness and severe lateral variation. In this study, the extrapolation inversion controlled by seismic facies is applied to this problem. Fristly, we interpret the log facies according to logging and core data, then transfer the log facies to seismic facies by well to seismic calibration, and subsequently introduce the seismic facies into inversion process to control the variation tendency and the time-window size of the inversion parameter. In addition, we also introduce the constraints of reconstructed log data and lateral continuity of seismic waveform to build the initial model in the extrapolation calculation. Our method is used to identify the Carboniferous area in western China buried deeply more than 3400 m with thickness of about 5 m. Under the condition of only water production in the well at structural high part, we targeted the ultra-thin lithologic reservoir at structural low part and implemented its distribution range.