饶阳凹陷任丘潜山油藏油源对比及有效烃源岩成藏贡献

为进一步研究饶阳凹陷任丘潜山油藏的原油来源及烃源岩的成藏贡献，根据原油和烃源岩的饱和烃气相色谱-质谱分析数据以及生物标志物特征，对潜山原油进行了详细分析，确定了其与烃源岩的亲缘关系，并通过地质条件分析解释了混源成藏的原因，最终确定了混源油的混源比例。C₂₉甾烷20S/（20S+20R）参数反映任丘潜山油藏原油基本为成熟原油，Pr/Ph、G/H、S/H、C₁₉/C₂₃等生物标志物参数表明任丘潜山油藏存在3种类型原油，分别为A类、B类和C类。3类原油生物标志物参数呈现规律性变化，并且空间分布亦存在一定规律性。A类为马西洼槽沙河街组三段中-下亚段（沙三段中-下亚段）烃源岩单一来源的原油，主要分布于任丘潜山北部偏东地区的奥陶系储层中。B类和C类原油为任西洼槽沙河街组一段下亚段（沙一段下亚段）和马西洼槽沙三段中-下亚段烃源岩混合来源的原油，其中B类原油中来自沙三段中-下亚段烃源岩的原油占比为60%~70%，其次为来自沙一段下亚段烃源岩的原油，主要分布于任丘潜山北部偏西地区的元古界雾迷山组和寒武系府君山组储层中。C类原油则以沙一段下亚段烃源岩贡献为主，来自沙三段中-下亚段烃源岩的原油占比较低，为30%~40%，集中分布于任丘潜山油藏南部地区的元古界雾迷山组储层中。整体上，沙一段下亚段烃源岩对任丘潜山油藏原油的贡献北低南高，而沙三段中-下亚段烃源岩则为北高南低。

Oil-source correlation and contributions of effective source rocks to accumulation in Renqiu buried hill reservoirs in the Raoyang sag

To further study the source of crude oil and the contributions of source rocks to accumulation in Renqiu buried hill reservoirs in the Raoyang sag, this paper detailedly analyzes the crude oil from the buried hill based on the analysis data of gas chromatography-mass spectrometry of saturated hydrocarbons and the biomarker characteristics of crude oil and source rocks, determines the relationship between crude oil and source rocks, explains the reason for source-mixed accumulation through analysis of the geological conditions, and finally determines the source-mixed ratio of the mixed oil. The C₂₉ sterane 20S/(20S+20R) reflects that the crude oil in Renqiu buried hill reservoirs is dominated by mature crude oil. The biomarker parameters such as Pr/Ph, G/H, S/H, and C₁₉/C₂₃ indicate that there are three types of crude oil in Renqiu buried hill reservoirs, namely Type A, B and C. The biomarker parameters of the three types of crude oil change regularly, presenting a regular spatial distribution. Type A is only originated from the source rock of the middle-lower submember of the third Member of Shahejie Formation in the Maxi subsag, and it is mainly distributed in the Ordovician reservoirs north by east of the Renqiu buried hill. Types B and C are sourced from the lower submember of the first Member of Shahejie Formation in the Renxi subsag and the middle-lower submember of the third Member of Shahejie Formation in the Maxi subsag. Type B from source rocks in the middle-lower submember of the third Member of Shahejie Formation accounts for 60%-70%, followed by the crude oil from the source rocks of the lower submember of the first Member of Shahejie Formation; the latter is mainly distributed in the Proterozoic Wumishan Formation and Cambrian Fujunshan Formation,in the north by west of the Renqiu buried hill. Type C is mainly from source rocks of the lower submember of the first Member of Shahejie Formation. The crude oil from the middle-lower submember of the third Member of Shahejie Formation accounts for 30%-40%, and is dominantly distributed in the Proterozoic Wumishan Formation in the southern Renqiu buried hill. On the whole, the contribution of source rocks of the lower submember in the first Member of Shahejie Formation to the Renqiu buried hill reservoir is low in the north and high in the south, while high in the north and low in the south for source rocks of the middle-lower submember in the third Member of Shahejie Formation.