红台地区低饱和度油气藏成藏主控因素分析

Key Controlling-Factors of Low-Saturation Hydrocarbon Accumulation in Hongtai

红台地区中侏罗统油气藏类型多,成藏条件优越。综合运用钻井、地震和测试化验等资料,分析了西山窑组四段油气藏类型和成藏主控因素,以指导该区低饱和度油气藏勘探。结果表明:该油气藏属于低饱和度油气藏,油气富集受控于储集层物性,紧邻生烃中心的水下分流河道砂体是有利的储集砂体;油气以纵向运移为主,中晚燕山期形成的逆冲断层是油气运移的主要通道;古构造控制了油气聚集,低幅度构造背景、后期构造运动相对稳定的区域是该油气藏大面积形成和保存的基础。下一步应围绕疙北鼻隆区和红台2、3号主体构造寻找断块、断鼻型低饱和度油气藏,扩展疙瘩台—红台斜坡带具有古构造背景、受岩性控制的构造-岩性油气藏,以扩大该区低饱和度油气藏的勘探规模。

The Middle Jurassic reservoirs in Hongtai are characterized by multiple types and favorable hydrocarbon accumulation conditions. The drilling,seismic and other test data are used to analyze the reservoir type and key controlling-factors of hydrocarbon accumulation in Xishanjiao-4 and provide guidance for the low-saturation hydrocarbon reservoir exploration in this area. Research shows that this reservoir is considered as a low-saturation hydrocarbon reservoir,hydrocarbon accumulation is controlled by reservoir properties,and subwater distributary channel sandbody that is close to hydrocarbon-generation center is considered as favorable reservoir sandbody. Hydrocarbon mainly migrates along the longitudinal direction and the thrust-faults develop in the middle-late Yanshanian provides main migration pathway. Hydrocarbon migration is mainly controlled by paleostructure,Lowamplitude tectonic setting and the area with relatively stable late tectonic movement lay a basis for the large-area hydrocarbon reservoir formation and preservation. The further exploration should focus on the fault-block and fault-nose low-saturation hydrocarbon reservoirs around the nose-uplift in the north of Gedatai. The further exploration should also focus on the structure-lithology hydrocarbon reservoirs controlled by lithology and paleostructure in Gedatai-Hongtai slope zone for exploration extension of low-saturation hydrocarbon reservoir in this area.