Sequence Stratigraphy Study And Reservoir Prediction Of Xujiahe Formation Upper Triassic In The Western Sichuan Foreland Basin

With further developments of oil and gas exploration theories and technical in foreland basin, the exploration of foreland basin obtains huge progresses in the world, the output rate of rank front 120 in the world of the big oil fields is 47% to the whole world oil and gas output, among these, there are more than 70 big oil fields in foreland basin(the rate is 59%); The outputs of rank front 14 in the world of very big oil and gas fields account for 20% of total outputs in world, among them 10 were located in foreland basin. Therefore, the exploration of foreland basins have become active field that make person's focus attention in China.The western Sichuan foreland basin is the typical growth in A type subduction peripheral foreland basin. The Sichuan basin is a compound basin that developed in the foundation of upper yangtze craton, the exploration history of oil and gas in the basin has more than 40 years, obtained large quantity important achievements and understandings. But the research is weaken for the sequence stratigraphy and sedimentary system of Upper Triassic, Xujiahe formation in the western Sichuan foreland basin. For long time, to the sedimentary system, sedimentary face types and characteristics, sequence stratigraphy characteristics, reservoir characteristics and space distribution of the beneficial reservoir and so on, that has not come into being system and deepening acquaintance. This paper on the sequence stratigraphy research in the western Sichuan foreland basin, built up sequence stratigraphy framework of this area, analyzed the lithofacies palaeogeography spreading characteristic in different sequence stratigraphy frameworks, clarified space distribution rules of beneficial reservoirs in the sequence stratigraphy framework, and predicted the distribution area of beneficial reservoirs in this area, obtained to the principally acquaintances as follows:1 The Xujiahe formation of Upper Triassic in the western Sichuan foreland basin mainly developed two major sedimentary systems: limited gulf-ramp deposite and delta-lake deposite. The mainly sedimentary face types have: delta, lake, alluvial fan, river and limited gulf etc. Among them, the delta deposite extremely developed, the...