关键词: 四川盆地, 石炭系, 天然气, 地层-构造复合圈闭, 气藏

Abstract: The carboniferous gas reserves and production in Eastern Sichuan are abruptly increased in recent years.The important reason is a lot of highly productive gas reservoirs with strutigraphic-structural trap,such as Wubaiti,Longmenchang and Menxi reservoirs,were discovered.The structures of reservoirs are too complicated to be recognized and predicted especially for reservoir pinch-out line.According to the drilling data in past years,the gas reservoirs are mainly distributed in the areas where carboniferous residuum thickness is more than 10m.So the reservoir pinch-out boundary is fixed on the 10m isopach of carboniferous residuum thickness.(Based on drilling data and interpretation of polarity,amplitude and moveout of seismic reflector in Permian bottom.)On the basis of carboniferous structures and their structural contour lines,it is forecasted that there are 48 kinds of carboniferous stratigraphic-structural combination traps which is divided into 8 types in Eastern Sichuan.The success radio of drilling traps is up to 65%.Most traps are not drilled until now.So there is a bright prospect in Eastern Sichuan.

Key words: Sichuan Basin, carboniferous, stratigraphic-structural combination trap, gas reservoir