黄陵地区储层成藏条件及主控因素

Accumulation conditions and main controlling factors of Chang 6 reservoir in Huangling Area

黄陵地区延长组长6致密储层为重点勘探层系,物性差,非均质性强。为了研究储层特征与油水分布关系,寻找油气富集规律,有效预测有利区,通过测井、录井、化验资料等,利用扫描电镜、铸体薄片,高压压汞技术等方法,对长7烃源岩、长6储层条件及储源配置关系、成藏驱动力等方面要素分析,进一步预测油气富集"甜点"模式,对储层地质与成藏特征进行总结。研究结果:长7烃源岩热演化程度好,是优质生油岩,油源受构造影响分区分布,西北部成熟度高于东南部,为成藏提供基础条件;长6受成岩作用、压实作用和胶结作用影响,物性变差,与长7形成良好储源配置关系;成藏运移阻力主要为毛细管力,范围在0.014~0.078 MPa,驱动力大于运移阻力,流体才会聚集成藏。结果表明:长6储层成藏受控于优质烃源岩展布、储层质量等,受多种地质因素控制和影响,浊积水道区域,发育成熟的孔-缝疏导系统,构造局部隆起带,控制致密油分布。

Chang 6 tight reservoir was the main layers of yanchang formation,which had poor physical properties and high heterogeneity.In order to study relationship between reservoir characteristics and oil-water distribution,find the law of hydrocarbon enrichment and predict effectively favorable area,Chang 7 source rock,Chang 6 reservoir and source-reservoir assemblage and reservoir power were analysised using the data on well logging,mud logging and analysis and the methods of cast section,scanning electron microscope（SEM）and mercury penetration techniques.Reservoir geology and accumulation were studied through “sweet spots” predictive.The results show：Chang 7 source rocks are the underlying condition with northwest maturity higher than the southeast;Chang 6 reservoir have poor physical properties because of diagenesis,compaction and cementation,but have good source-reservoir assemblage with Chang 7;Oil reservoir can be assembled which accumulation power is much greater than the capillary force.Movement resistance of the capillary force is between 0.001 4～0.078 MPa.The results indicate that Chang 6 reservoir is controlled by reservoir quality and source rock distribution.Multiple factors influence the Chang 6 reservoir,which are turbidite channel,well-developed pore-seam dredging system,local tectonic belts.