源下致密砂岩油成藏特征、控制因素和运聚模式——以松辽盆地大安地区白垩系泉头组扶余油层为例  

Accumulation characteristics, controlling factors and migration-accumulation model of tight sandstone oil below source rocks: A case study of Fuyu reservoirs of the Cretaceous Quantou formation in Da’an area of Songliao

作　　者：孙雨[1] 刘如昊 于利民[1] 闫百泉[1] 文慧俭[1] 孙扬 SUN Yu;LIU Ruhao;YU Liming;YAN Baiquan;WEN Huijian;SUN Yang(College of Geosciences, Northeast Petroleum University, Daqing, Heilongjiang 163318, China)

机构地区：[1]东北石油大学地球科学学院

出　　处：《中国矿业大学学报》2019年第4期793-805,共13页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(41872158);黑龙江省普通本科高等学校青年创新人才培养计划项目(UNPYSCT-2016081)

摘　　要：为了加深对致密砂岩油的成藏特征及其控制因素的认识,以松辽盆地大安地区白垩系泉头组扶余油层为例,通过物性测试、薄片显微观察、包裹体均一温度测定和地层水矿化度分析等手段,总结了致密砂岩储集层特征、源储组合方式、石油成藏时间、油水分异程度、石油富集特征等成藏特征,分析了源储组合方式、剩余压差、致密砂岩储集层的分布及其内部非均质性对致密砂岩油形成的控制作用,认为不同类型源储组合条件下石油发生差异性运聚,控制了致密砂岩油的分布特征和富集程度.研究结果表明:扶余油层致密砂岩储集层呈"平面多支、垂向多层"的分布特征;扶余油层上部与上覆青山口组烃源岩直接接触,形成了紧邻型源储组合,扶余油层中下部与青山口组烃源岩不能直接接触,形成了分离型源储组合;砂岩储集层致密化时间为姚家组沉积时期,早于石油充注时间,属于"先致密后成藏型"致密砂岩油藏;石油二次运移距离较短,油水分异程度差,整体呈准连续型分布,但富集程度差异大.源储组合方式、剩余压差、致密砂岩储集层分布及其内部非均质性是源下致密砂岩油的成藏特征的主要控制因素.综合分析认为,源储紧邻型致密砂岩油以短距离"面式运移"方式,通过源储界面附近的微裂缝和储集层中的孔隙直接向储集层中幕式充注,在致密砂岩储集层中运移距离可达40~300 m,受微裂缝发育特征和储集层非均质性影响,石油在储集层中发生差异性运聚,富集于优势运移通道附近;源储分离型致密砂岩油呈"点或线状横向推进式运移"方式在致密砂岩储集层中运移,横向运移距离可达30~850 m,储集层内部"甜点"为主要通道和富集部位.To deepen the understanding of accumulation characteristics and its controlling factors of tight sandstone oil, taking Fuyu reservoirs of Cretaceous Quantou formation in Da’an area of Songliao basin as an example, characteristics of tight sandstone reservoirs, combined manner of source-reservoirs, hydrocarbon accumulation period, oil-water differentiation and oil enrichment characteristics were summarized based on physical properties of reservoirs testing, microscopic observation of thin sections, homogenization temperature of fluid inclusion testing and analysis of formation water salinity. Combined manner of source-reservoirs, residual pressure difference, distribution and heterogeneity of tight sandstone reservoirs and their control on hydrocarbon accumulation in tight sandstone were studied. It is indicated that the migration-accumulation model of tight sandstone oil is different under different combined manner of source-reservoirs, controlling the distribution characteristics and enrichment of tight sandstone oil. The results show that the distribution characteristics of tight sandstone reservoirs in Fuyu reservoir are multi-branch in plane and multi-layer in vertical direction. The upper part of the Fuyu reservoirs contacts with the source rocks of the Cretaceous Qingshankou formation, forming an adjacent combined manner of source-reservoirs. The middle and lower parts of Fuyu reservoirs are not in contact with the source rocks of the Cretaceous Qingshankou formation, forming separate combined manner of source-reservoirs. Sandstone of Fuyu reservoirs became tightened during the depositional period of the Cretaceous Yaojia formation, which is earlier than the hydrocarbon accumulation period. Therefore, it belongs to the reservoirs for oil emplacement occurred later than tight rock formed. The secondary migration distance of oil is relatively short, and the oil-water differentiation is poor. Although the distribution of oil is quasi-continuous, the oil enrichment is very different. Combined manner of source

关 键 词：致密砂岩油 运聚模式 成藏特征 非常规储集层 扶余油层 松辽盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]