PETROLEUM EXPLORATION DOMAINS OF CONTINENTAL NONSTRUCTURAL TRAPS IN CHINA

Exploration activity in main continental oil-producing area in China has entered a stage focusing on exploration of nonstructural traps.The development and distribution of nonstructural traps in fault basin,depressional basin and foreland basin were summarized in accordance with the main controlling factors of basin formation and its total structural pattern.The following 6 domains must be paid more attention to:a) area with repeated depositional facies change;b) unloading area of depression;c) break in steep slope and flexural fold in gentle slope;d) pericline,pitching end and overlying stratigraphy of paleo-uplift;e) lower part and footwall of fault block;and f) synclinorium.Exploration in Ordos,Songliao,Bohaiwan,north Jiangsu and Nanyang basins are dominated by nonstructural traps.However,exploration of nonstructural traps in basins in central and west China and offshore area has just been started and many potential domains for petroleum exploration are remained.