鄂尔多斯盆地南部延长组事件沉积与致密油的关系

发布时间：2018-11-04 20:23

【摘要】：根据大量的岩心观察、钻测井资料、野外剖面观测及分析化验资料,对鄂尔多斯盆地南部延长组事件沉积及与致密油的关系进行研究。结果表明:研究区主要存在地震事件、火山事件、缺氧事件和重力流沉积4种典型的事件沉积现象,对各个事件沉积的共生组合关系进行分析,发现主要存在4种典型的组合关系,其中深水重力流沉积中的多期砂质碎屑流及多期浊积岩的垂向叠置最为常见,地震、火山诱发浊流沉积形成震浊积岩,并可见油页岩与浊积岩和凝灰岩的组合配置关系;研究表明研究区在长6—长7期主要发生5.5~6.5级地震;三角洲前缘斜坡至半深湖—深湖区是记录事件沉积的重要区域,其中前缘斜坡坡脚处滑塌砂体的事件沉积记录最为丰富,深湖区是震浊积岩主要发育区域;缺氧事件形成的优质烃源岩是致密油藏的油源,重力流砂体是研究区致密油的重要储集层,同时地震事件及火山事件对储层也进行了有益的改造,砂质碎屑流沉积的储集层物性及含油性最好。
[Abstract]:Based on a large number of core observations, drilling logging data, field profile observations and analysis of laboratory data, the relationship between event deposition and dense oil in Yanchang formation in southern Ordos Basin was studied. The results show that there are four typical event deposition phenomena in the study area, such as seismic events, volcanic events, anoxic events and gravity flow deposition. The symbiotic assemblage of each event deposit is analyzed. It is found that there are mainly four typical assemblages, among which the multi-stage sand clastic flow and the vertical overlay of the multi-stage turbidite are the most common in the deep-water gravity flow deposition, and the seismicity and volcano-induced turbidite deposit form the seismoturbidite. The combination and disposition of oil shale with turbidite and tuff can also be seen. The study shows that the earthquake with M = 5.5 and M = 6.5 occurred mainly in the Chang6-Chang7 period in the study area. The delta front slope to the semi-deep lacustry-deep lake region is an important area to record the event deposition, among which the event deposition of the sloping sand body at the foot of the front slope is the most abundant, and the deep lake region is the main area of seismoturbidite development. The high quality hydrocarbon source rock formed by anoxic events is the oil source of the tight reservoir, the gravity flow sand body is the important reservoir of the dense oil in the study area, and the seismic and volcanic events have also carried on the beneficial transformation to the reservoir. The reservoir physical properties and oil content of sand clastic flow deposition are the best.
【作者单位】：中国石油大学地球科学与技术学院;陕西延长油田股份有限公司;国土资源部油气资源战略研究中心;
【基金】：国家自然科学基金项目(41572088) 中央高校基本科研业务费专项(15CX06002A) 中国石油大学(华东)研究生创新工程(YCX2015004)
【分类号】：P618.13

【相似文献】