松辽盆地北部油气垂向运移及对成藏与分布的控制

Oil-Gas Vertical Migration and Its Controlment to Formation and Distribution of Oil-Gas Reservoirs in the North of Songliao Basin

付广 杨丰平 孟庆芬 杜春国

FU Guang YANG Feng-ping MENG Qing-fen DU Chun-guo

大庆石油学院, 黑龙江 大庆 163318; 大庆油田 勘探公司, 黑龙江 大庆 163712

Daqing Petroleum Institute, Daqing 163318, China; Exploration Company of Daqing Oil Field, Daqing 163712, China

在研究松辽盆地北部油气运聚成藏特征的基础上,对油气垂向运移的特征进行了研究,指出断裂是油气垂向运移的唯一通道。油气沿断裂既可发生向上的垂向运移,又可发生向下的倒贯运移,主要取决于油气垂向运移的动力。如果源岩具异常孔隙流体压力,其生成的油气可同时发生向上和向下的垂向运移;如果源岩不具异常孔隙流体压力,其生成的油气只能发生垂向运移。油气垂向运移动力和通道发育是决定油气垂向运聚成藏与分布的主要因素,在松辽盆地具体表现为,长期断裂控制着沙河子组~营城组源岩生成天然气在浅层的聚集与分布,异常孔隙流体压力和T2 断裂共同控制着扶、杨油层的运聚与分布,T2 或T1 至T06断裂控制着黑帝庙油层油气藏的形成与分布。

Based on the study of the migration and accumulation characteristics of oil or gas in the north of Songliao Basin, this paper studies the vertical migration characteristics of oil or gas. It points out faults to be the sole passages of oil or gas vertical migration.Oil or gas can only migrate through faults both upwards and downwards.Oil or gas vertical migration upwards or downwards is determined by the power of oil or gas vertical migration. If there is abnormal pore fluid pressure in hydrocarbon source rock, oil or gas can migrate upwards and downwards. If there is no abnormal pore fluid pressure in hydrocarbon source rock, oil or gas can only migrate upwards. The power and passages of oil or gas vertical migration are the main factors controlling the formation and distribution of oil or gas reservoirs in the vertical direction. They show in following three aspects in the north of Songliao Basin: The long-term development faults control accumulation and distribution of gas from K1sh+yc source rock in shallow strata; abnormal pore fluid pressure and T2 faults control accumulation and distribution of oil or gas in F,Y oil layers; the faults from T2 or T1 to T06 control accumulation and distribution of oil or gas in H oil layer.