松辽盆地北部敖古拉断裂带对油气运聚的控制分析

Controlling Effect of Aogula Fault Zone on Oil and Gas Migration and Accumulation in Northern Songliao Basin

摘要: 在对敖古拉断裂带及周边断层的活动特征研究基础上，从油气的生成、运移、聚集的角度综合分析断裂带对敖古拉油田油气聚集的影响。断层的开合与油气生成、运移等要素的时空匹配关系对研究区的成藏起到了至关重要的控制作用。齐家–古龙凹陷青山口组源岩从嫩江组沉积末期开始生烃，嫩江组末期、明水组一段沉积末期和明水组沉积后期敖古拉断层发生三次正断，第三纪末期，受SSE-NNW向区域挤压应力作用，断裂带发生反转逆冲，断层开启为油气疏导打开通道，青一段油源沿断裂带向上运移；长期不活动断层闭合对油气起到封堵作用，使油气在上覆萨尔图油层、葡萄花油层有利区带富集成藏。受断裂带活动性及平面展布特征的影响，敖古拉油田扶余油层在断裂带东部成藏，萨尔图油层、葡萄花油层油气沿敖古拉断裂带西侧呈北东向线性展布。

Abstract: Based on the study of the active characteristics of Aogula Fault Zone and its surrounding faults, the influence of fault zone on oil and gas reservoirs in Aogula Oilfield was comprehensively analyzed from the aspects of oil and gas generation, migration and accumulation. The temporal and spatial matching relationship between fault opening and closing, oil and gas generation, migration and other elements played an important role in controlling reservoir formation in the study area. Source rocks of Qingshankou Formation in Qijia-Gulong Sag began to generate hydrocarbons from the late sedimentary stage of Nenjiang Formation, three positive faults occurred at the end of Nenjiang Formation, at the end of the first member of Mingshui Formation and at the late sedimentary stage of Mingshui Formation. At the end of Tertiary, due to the regional compression stress from SSE-NNW, the fault zone was reversed and thrust, the fault was opened for oil and gas migration and transport, and the oil source from the first member of Qingshankou Formation migrated upward along the fault zone. Long-term inactivity fault closure played a blocking role in oil and gas, so that oil and gas accumulation and reservoir formation in Saltu and Putaohua Reservoirs affected by the activity of the fault zone and the characteristics of plane distribution. Fuyu Reservoir in Aogula Oilfield forms reservoirs in the eastern part of the fault zone, and the oil and gas in Saltu and Putaohua Reservoirs distribute linearly along the west side of the Aogula Fault Zone.