二连盆地乌里雅斯太凹陷北洼构造特征及成藏规律研究

发布时间：2018-02-12 10:52

本文关键词： 构造特征成藏规律乌里雅斯太凹陷二连盆地　出处：《西北大学》2015年硕士论文　论文类型：学位论文

【摘要】：乌里雅斯太凹陷北洼位于二连盆地马尼特坳陷东北端,在下白垩统多个层位发现了工业油流,具有良好的勘探前景,目前对油藏的层位划分、具体的构造位置及形态特征、油藏分布规律及主控因素缺乏统一的认识,影响了北洼油气勘探成果的扩大。本文在收集大量基础资料和前人研究成果的基础上,以地球物理勘探、构造地质学、现代石油地质学、沉积学等基本理论为指导,对研究区地层展布情况、构造特征、沉积相及储层特征进行了深入的研究,在此基础上,剖析了研究区油气藏的成藏条件及成藏过程,确定了研究区油气成藏的主控因素,建立了乌里雅斯太凹陷北洼油气分布序列和成藏模式,指出了研究区下步勘探主要方向,对该区的勘探开发具有重要的指导作用。研究区可划分为2个洼槽和5个正向构造带,断裂发育,平面上按断层走向可划分为四组,剖面上呈多种断裂组合样式。早白垩世以来主要经历了断陷初期、断陷稳定期、断陷萎缩期、回返抬升期四个阶段。阿尔善组和腾一下是研究区主要的油气生、储层系。阿尔善组发育西北及东南两大扇三角洲体,为近源高能沉积,阿四期经历了两次湖退及两次湖侵,形成了阿42、阿44、阿45三套较厚储集层,岩性以成分和结构成熟度都低的砂砾岩为主,整体储集性能较差,为油气聚集的主要场所。腾一下以湖相沉积为主,为研究区最重要的烃源层及区域盖层,阿43、阿31为较重要烃源层和局部盖层。研究区包括三大类共七种油气藏类型,以侧变式生储盖组合为主,洼槽带内生成的烃类可沿着油源断层及不整合面运移至各类圈闭中聚集成藏,基本可概括为3种成藏模式。油气的分布与富集受构造格局、主力生油洼槽、断裂及不整合面、储集体及储盖组合的控制。西部鼻状构造带、东部鼻状构造带和中部断垒带为研究区有利构造区带,区带内油源断裂及T8不整合面附近的各种圈闭配合储集体发育的有利相带是油气富集的最佳场所,东部鼻状构造带勘探程度最低,是研究区下步勘探的重点区带。中部大断裂东部和H25井区西部的3个交叉断层断块圈闭成藏条件较好,为研究区3个有利目标区。
[Abstract]:The northern depression of Wuli Yatai depression is located at the northeast end of Manitt depression in Erlian basin. Industrial oil flow has been discovered in many lower Cretaceous strata, which has good prospect for exploration. At present, the reservoir is divided into layers, specific structural location and morphological characteristics. The lack of a unified understanding of reservoir distribution and main controlling factors has affected the expansion of oil and gas exploration results in Beiwa. Based on the collection of a large number of basic data and previous research results, this paper makes use of geophysical exploration and tectonic geology. Based on the basic theories of modern petroleum geology and sedimentology, the stratigraphic distribution, structural characteristics, sedimentary facies and reservoir characteristics in the study area are studied. This paper analyzes the reservoir forming conditions and the process of oil and gas accumulation in the study area, determines the main controlling factors of the oil and gas accumulation in the study area, establishes the oil and gas distribution sequence and the reservoir forming model in the north depression of the Wulyatai sag, and points out the main direction of the next step exploration in the study area. The study area can be divided into two troughs and five forward structural zones, the faults are developed, and the plane can be divided into four groups according to the fault strike. There are many types of fault assemblages in the section. Since the early Cretaceous, they have mainly experienced four stages: the early stage of the fault depression, the stable period of the fault depression, the period of depression atrophy, and the stage of returning to uplift. The Arshan formation and Tengshen formation are the main oil and gas generation in the study area. Reservoir system. The Arshan formation developed two large fan deltas in the northwest and southeast of China, which are near source high-energy deposits, and experienced two lake retreating and two lake transgressions in the fourth stage, resulting in the formation of three sets of thicker reservoirs A 42, A 44 and A 45. The lithology is dominated by sandy gravel with low compositional and structural maturity, and its overall reservoir performance is poor, which is the main place for oil and gas accumulation. The main reservoir is lacustrine facies, which is the most important hydrocarbon source bed and regional caprock in the study area. A 43 and a 31 are relatively important hydrocarbon source beds and local caprocks. The study area consists of three types of seven types of oil and gas reservoirs, mainly lateral variant generation, reservoir and caprock assemblages. Hydrocarbon generated in the lacustrine belt can be transported to various traps along the source fault and unconformable surface to form reservoirs, which can be summed up as three types of reservoir forming models. The distribution and enrichment of oil and gas are characterized by structural pattern, main oil generating troughs, faults and unconformities. The control of reservoir body and reservoir cap assemblage. The favorable structural zones in the study area are the western nasal structural belt, the eastern nasal structural belt and the central fault barrier zone. The favorable facies zone of oil-source faults and various traps near T8 unconformities is the best place for oil and gas enrichment, and the nasal structural belt in the east is the lowest in exploration. The three cross fault block traps in the eastern part of the central big fault and the west of H25 well area are better in forming reservoir conditions and are favorable target areas for the study area.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.130.2

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