陆相断陷盆地成烃与成藏组合关系研究——以胜坨油田为例

The Causative Assemblages of Oil Pools Based on Hydrocarbon Generation and Accumulation Process in Terrestrial Rift Basin:A case study from Shengtuo Oilfield

有效烃源岩和油气藏的空间组合关系是油气成藏规律研究的关键,理清这种关系及其主要控制因素对于剩余油气藏勘探和预测具有重要意义。以中国东部具有39年开发历史的老油田——胜坨油田为例,以精细油源对比为基础,通过对其成烃与成藏组合关系的研究,提出了高勘探程度地区寻找隐蔽油气藏的一种新思路。油源对比表明,Es3下和Es4上优质烃源岩是胜坨油田的主力烃源岩,其中坨二-坨三区主要源自Es4上亚段,坨-区主要源自Es3下亚段。油藏水化学和断裂发育特征分析表明,胜北大断层沟通了储集层和主力油源层,是油气运移的主要垂向输导体系。从油气的运聚过程、成烃与成藏组合关系以及资源潜力分析,区内已经发现的油藏以它源型为主,据此推断在古近系较深部位应存在自源型油藏,而在陡坡带包括潜山中应存在它源型油藏,并且具有相当的规模。

The relation assemblage of oil pools and its effective hydrocarbon source rocks is the key factor in the study of pool-forming process, and to elucidate its controlling factors will do much help in the exploration and forecasting of the remaining unfound reservoirs. In this article Shengtuo oilfield with 39 years of exploitation history in the east of China is taken as an example for the study. Based on oil and source correlation, the time and space assemblages of oil reservoirs and its hydrocarbon generation and accumulation process are studied, and a new research procedure for subtle reservoir exploration is put forward. The study indicates Shengtuo oilfield is mainly sourced from excellent hydrocarbon source rocks, that is the oils from Area Ⅰ , and Area Ⅲ are mainly sourced from Es u 4 while the oils from Area I is sourced mainly from Es 1 3. Reservoir water chemistry and fault system studies imply that Shengbei fault is the most important vertical conduit, since it is a source fault connecting the effective source rocks and the reservoir. As the oil pools found before are all else-sourced, it is believed that self-sourced oil pools with certain size should exist in the deep part of Paleogene and the burial hills on the steep slope.