东濮凹陷胡状集油田油气输导体系及模式

东濮凹陷胡状集油田位于凹陷缓坡,多条近平行的二级断层将其切割形成断阶构造,伴生的三、四级断层将构造进一步复杂化。研究区发育辫状河三角洲沉积,砂、泥岩频繁间互,砂体、断层及其相互配置构成了胡状集油田复杂的油气输导体系,对油气运移和聚集具有重要作用。通过分析胡状集油田胡5断块区输导体系与油气分布的关系发现,胡状集油田为其东侧洼陷带烃源岩生成的油气近东西向运移至斜坡带聚集形成;砂体厚度和断距控制断层两侧的岩性对置关系,进而影响断层的侧向封闭性。砂体与断层配置形成2种油气输导模式,并控制研究区油气的运移和聚集。对于走向与主断层平行的断层,当断距较小且砂岩厚度较大时,具有输导油气的作用;当断距较大时,可断开厚层砂体,有利于油气聚集。对于与主断层斜交的断层,其断距较小且砂体厚度较大的部位有利于油气输导,而断距较大且砂体厚度较小的部位则易于封堵油气。

The carrier system and model of Huzhuangji oilfield in Dongpu depression

Huzhuangji area in the west slope of Dongpu depression is complex in structure with frequent alternation of sandstone and mudstone. Sandstones and faults are configured to form a complex oil and gas carrier system, which has great influence on oil and gas migration and accumulation in this area. This paper focuses on the relationship between the carrier systems and the hydrocarbon distribution in Hu5 block area of Huzhuangji oilfield. The analysis results show that: oil and gas generated from the source rock in the east sag of Huzhuangji oilfield migrated nearly east-west to the slope and accumulated; the thickness of sand body and the fault distance control the lithology contraposition of the two sides of the fault, thereby affecting lateral fault sealing. Two types of carrier system that consist of different sand body and fault combinations were analyzed and their control on the hydrocarbon migration and accumulation in this area. For faults parallel to the strike of the main fault, they are favorable for oil and gas migration if their fault distance is small combining with thick sandstones; and they are favorable for oil and gas accumulation if their fault distance is large enough to disconnect the thick sand bodies; and for faults oblique crossing the main fault, it is favorable for oil and gas migration where the fault distance is small and sand body is thick; and tis favorable for hydrocarbon accumulation where the fault distance is large and sand body is thin.