STUDY ON DEEP BASIN GAS IN THE WESTERN SICHUAN DEPRESSION, THE SICHUAN BASIN

Natural gas in deep basin reservoirs is one type of tight sandstone gas pools, and its exploration strategy is wholly different from normal reservoirs due to its special characteristics and mechanism of gas accumulation. Is there any deep basin gas in tight clastics of continental facies in the Western Sichuan Depression? There were much different arguments about that. The gas accumulation mechanism and gas reservoir characteristics in the Westem Sichuan Depression were compared with those of deep basin gas reservoirs in North American. It was considered that typical characteristics of deep basin gas had not been discovered in the Upper Triassic reservoirs. The gas accumulation mechanism of the Western Sichuan Depression is different from those of deep basin gas reservoirs. The complex gas accumulation model of "normal accumulotion in the early stage and modification in the late" was suggested.