Lithologic Trap Prediction and Reservoir Distribution of Wutonggou Formation in Eastern Junggar Basin

This paper identifies the reservoirs and traps in the submarine fan of Wutonggou formation in Q block in the eastern Junggar basin by means of stratigraphy,log-constrained inversion and seismic attributions optimization,and then detects the reservoir scopes using predicted oil saturation.The Wutonggou formation of Upper Permian in Q block can be divided into three parts: Lowstand systems tract,transgressive systems tract and highstand systems tract,among which the sand body of Lowstand systems tract is the target of this research.The braided channel in the middle fan is the best reservoir.The original sandstone was sealed by mudstone in transgressive systems tract.Therefore,updip pinchout lithologic traps were formed with tectonic uplifting.The positions of reservoirs and lithologic traps are ascertained by using the log-constrained inversion.After the seismic attributes optimizing based on genetic algorithm-neuron network optimization,the result shows that the areas of high oil saturation are located in the west and the southwest in this region,of which the southwest reservoir is much better in quality and petroliferous property than the west.