松辽盆地长岭凹陷腰英台地区坳陷层油气成藏耦合与成藏模式解析

Reservoir coupling and accumulation pattern of depression in Yaoyingtai area of Changling Sag,Songliao Basin

从构造格局背景、沉积层序演化背景和油气成藏石油地质条件等综合因素进行分析,认为长岭凹陷腰英台地区具备形成构造—岩性复合油气藏的资源条件。其区域油气成藏耦合关系良好,复合圈闭的定型期稍早于或同步于大规模烃源成熟期,油气生排烃后就近运移至复合圈闭中而聚集成藏,断层和砂体作为输导通道与复合圈闭相互优势匹配。在一系列走向近南北的正断层与各种类型砂体圈闭的相互配置下,详细解析认为其形成的构造—岩性复合油气藏主要有6种成藏模式。有利成藏区带评价预测出腰英台地区西部断坡带以东区域是油气成藏的有利区带。受构造演化格局与沉积相带叠置关系的双重控制,腰英台地区具有亿吨级大中型整装构造—岩性复合油气藏的良好前景。

Based on the comprehensive analyses of tectonic settings, sedimentary sequence evolution bacK- grounds and geologic conditions for petroleum accumulation, Yaoyingtai area in the Changling Sag was qualified for the generation of tectonic-lithologic composite reservoirs. Regional hydrocarbon accumulation conditions were well coupled and composite traps were formed earlier than or at the same time as large scale hydrocarbon source maturation. Oil and gas generated and migrated into the nearest traps. Faults and sand bodies worked as migra- tion channels and matched well with composite traps. By analyzing the collocation relationship between a series of north-south oriented normal faults and various types of sand traps, tectonic-lithologic reservoirs were mainly di- vided into six formation patterns. According to favorable reservoir area assessments, the area to the east of the western ramp in Yaoyingtai area was predicted as favorable reservoir zone. Yaoyingtai area, which was controlled by tectonic evolution pattern and sedimentary facies superposition, has a good prospect for billions of tons of large and medium-sized tectonic-lithologic composite reservoirs.