Abstract: As hydrocarbon exploration focus in the Shengli Oilfield gradually shifted from structural reservoir to hidden reservoir, the glutenite reservoirs have become important exploration targets. Increasing in prospecting efforts and application of new technologies also make the steep slope of the faulted lake basin a target of special interest. Seismic facies controlled inversion has the full advantage that the macroscopic geological bodies and lithology are controlled by seismic facies. It divides the target strata into sedimentary units of different sedimentary characteristics; it constrains the initial value range of each sampling point according to the low frequency background, and controls the window size at the same time, so that the inversion results should have definitive geological significance. The glutenite reservoir of the steep slope belt in the Chexi Sag is a multigenesis deposit with rapid changing lithofacies, making its description difficult. Using seismic facies controlled inversion, where detailed division of sedimentary facies and reservoir physical property analysis were made under the constrains of well log data, the “sweet spot” distribution of the Paleogenes third member of the lower Es3 steep slope reservoir was predicted. As a result, four “sweet spot areas” were identified in the middle and distal end of a braided channel, one of the most favorable reservoir facies. Prediction results show that glutenite identification reached the sand group level with some locations up to the level of small layers in the vertical direction. In the lateral direction, different genetic types of sand body could be distinguished clearly, and the nearshore subaqueous fan and slump fan glutenite reservoir were also better identified, which significantly improved the accuracy of sweet spot prediction for the steep slope of the faulted lake basin glutenite reservoir.

Key words: sweet spot prediction, sandconglomerate reservoir, steep slope of faulted lake basin, seismic facies controlled inversion