源外鼻状构造区油运移输导通道及对成藏的作用——以松辽盆地尚家地区为例

尚家地区为一鼻状构造,位于三肇凹陷下白垩统青山口组一段油源区之外,其石油的成藏与分布主要受输导通道的控制.能否正确认识该区石油输导通道及对成藏的作用.对于指导该区石油勘探和丰富油气成藏理论均具重要意义.采用油源对比、典型油藏解剖和成藏模式的研究方法,对尚家地区石油输导过程进行了研究,将其划分为以下3个部分:①T2源断裂是三肇凹陷青山口组一段源岩牛成石油向下伏下白垩统泉头组四段扶余油层、下白垩统泉头组三段杨大城子油层"倒灌"运移的输导通道;②被T2-T2-2断裂沟通的砂体是扶余、杨大城子油层石油从三肇凹陷向尚家地区侧向运移的输导通道;③T2-T1-1断裂是尚家地区扶余、杨大城子油层石油向上覆下白垩统姚家组葡萄花油层运移的输导通道.采用石油输导通道和石油分布之间匹配关系的研究方法,对尚家地区输导通道对石油成藏与分布中的作用进行了研究,得到T2源断裂越发育,三肇凹陷向尚家地区侧向运移的油源越充足;被T2-T2-2断裂沟通的砂体输导通道化置和能力控制着扶余、杨大城子油层和下白垩统泉头组二段石油的分布及富集程度;T2-T1-1断裂输导通道分布控制着尚家地区葡萄花油层的石油富集区域.

Oil Migration Transporting Pathways in Nose Structure Region outside Oil Source Area and Their Controlling on Oil Accumulation——Example of ShangJia region in the Songliao basin

The Shangjia region is a nose structure.It is located outside the oil area of K_1qn~1 (lst Member,Qingshankou Formation,Lower Cretaceous) in the Sanzhao depression,Songliao Basin.In this region oil accumulation and distribution are controlled by transporting pathways. It is of important significances for orienting oil exploration and enriching oil--gas accumulation theory that transporting pathways of oil and their controlling on oil accumulation and distribution are recognized in a region.Using the method of oil source correlation,typical oil reservoirs anatomy and oil accumulation models,oil transporting process in the Shangjia region,Songliao basin,was studied.It is classified into 3 parts:(1) T2 faults connecting source--rock were transporting pathways for migration downward of oil from K_1qn~1 source rocks into Fuyu oil layer,Yangdachengzi oil layer,the 4th and the 3rd Member of the Lower Cretaceous Quantou Fm.,respectively,in the Sanzhao depression.(2) Sand bodies connecting by T_2-- T_(2-2) faults were transporting pathways for oil in Fuyu,Yangdachengzi oil layers migrating laterally from the Sanzhao depression to the Shangjia region.(3) T_2--T_(1-1) faults were transporting pathways for oil in Fuyu,Yangdachengzi oil layer migrating to Putaohua oil layer,the Lower Cretaceous Yaojia Fro.,in the Shangjia region.Using the method studying the relation between oil transporting pathways and oil distribution,controlling of transporting pathways on oil accumulation and distribution was studied.It was concluded that the more developed the faults were,the more sufficient the oil source for lateral migration from the Sanzhao depression to the Shangjia region was.The position and ability of transporting pathways which were sand bodies connected by T_2--T_(1-1) faults controlled the distribution and abundant degree of oil in Fuyu,Yangdachengzi oil layers and K_1q~2.The distribution of T_2--T_(1-1) faults transporting pathways controlled the abundant area of Putaohua oil layer in the Shangjia area.