【作者】 侯献华；

【导师】 张永生； 吴河勇； 王世辉；

【作者基本信息】 中国地质科学院 ， 矿产普查与勘探， 2008， 博士

【摘要】 汤原断陷是伊舒地堑北部的一个次级断陷,几次评价结果均显示其有着可观的油气资源量,但至今,在地质勘探上仍未获大的突破。本文通过对已有地震资料的重新解释,认为汤原断陷的构造特征为主要发育北东向和北西西向断裂,其次发育近东西向和近南北向断层,两组骨干的断裂使汤原断陷整体表现为东西分带、南北分块的构造格架,断陷经历了中生代断陷期、新生代的强烈断陷期、持续断陷期、断凹转化期、断陷萎缩期、断陷消亡期六构造演化阶段。通过对研究区古生物、岩性、测井和地震等资料综合分析,重新进行地震地质层位标定,利用井震合成记录、基干井间地层对比等手段,对汤原断陷的地层进行了划分对比,调整了原有的分层数据,证实了白垩系和古新统乌云组地层的存在与大致分布范围。综合露头、岩芯、测井和地震的研究成果,按四分法无级层序的划分方法,建立了汤原断陷的层序地层格架,识别出了2个巨层序、3个超层序、20个三级层序。通过对钻井岩芯的观察描述,进行岩芯相分析,同时,开展测井相和地震相研究,建立了研究区地震相沉积相的对应关系,识别出了扇三角洲相、湖泊相和湖底扇相3种主要相类型,进一步划分出7种沉积亚相和17种沉积微相。综合研究生、储、盖层特征认为,烃源岩主要有两大类,即暗色泥岩和煤,以暗色泥岩为主。通过对烃源岩有机地化分析可知,汤原断陷有机质类型主要为Ⅲ型,少部分为ⅡB型,个别为ⅡA型;目的层段有机质的丰度以宝一段、达一段和乌云组最好,新安村组次之,宝二段和白垩系较差;有机质的成熟度随着埋深增加而增大。从油气源追踪对比结果来看,达连河组和新安村组湖相泥质岩是湖相油的主要烃源层,新安村组和乌云组煤系地层是煤系油的主要烃源岩。宝泉岭组一段和白垩系暗色泥岩是潜在的烃源岩。组成汤原断陷的储层岩性以不等粒砂岩、混合砂岩、砂砾岩及岩屑长石砂岩为主,指出其物性一般为中孔—中渗为主。汤原断陷油气藏的生储盖组合分为三种主要类型,即自生自储型、下生上储型和新生古储型。汤原断陷总的石油资源量为0.952～2.509×10~8t,天然气资源量为203.15～469.6×10~8m~3。可见汤原断陷资源前景可观。综合分析油气地质条件(生、储、盖、圈、运、保)后,对汤原断陷的有利勘探区带进行了预测,并指出了下一步的勘探方向。更多还原

【Abstract】 Tangyuan fault depression is a second-order one in the north of Yishu graben. Several evaluation results about the Tangyuan fault depression show a considerable amount of oil and gas resources, but so far, a major breakthrough of geological exploration has not come forth.Based on the re-interpreted seismic data, this paper considers the structural feature of Tangyuan fault depression is mainly the development of NE-striking and NSS-striking fracture, secondly ES-striking and SN- striking fracture nearly. Two group of leading faults make the whole Tangyuan fault depression exhibit west-eastern belted and south-north partitioned structural pattern. Tangyuan fault depression has gone through six tectonic evolution stage: fault depression in Mesozoic, and intense, sustained, fault-concave transformed, atrophic, extinct fault depression in Cenozoic. Through the comprehensive analysis for the data of paleontology, lithology, logging and seism in the study area, the seismic geological position is re-calbrated. By means of the record of well-earthquake synthesis and the strata correlation of leading wells among, the paper divides and correlates the stratum of Tangyuan fault depression, adjusts the original layered data, and then confirms the existence of Cretaceous and Paleocene Wuyun Formation and its general distribution range. Synthesizing the research results of outcrop, core, logging and seism, by the divided method of quartering stepless sequences, the paper establishes the sequence stratigraphic framework of Tangyuan fault depression, and classifies two megasequences, three super sequences, twenty three-order sequences. Through the observation and description of the core drilling, the phase-analysis for the cores are made. At the same time, carrying out the study on the logging and seismic phase, the paper establishes the corresponding relation of seismic and sedimentary facies in the study area, recognizes three main phase types of fan delta facies, lacustrine facies and sublacustrine fan facies, and classifies further seven kinds of sedimentary sub-phases and seventeen kinds of sedimentary micro-phases.Comprehensive study on the character of the source bed, reservoir and cap cover shows, there are two major types of source rocks, which are dark mudstone and coal, mainly to dark mudstone. Through the organic geochemical analysis for the source rocks, it is clear that organic matter type is mainlyⅢtype,ⅡB type partly,ⅡA type individually. The best organic-matter abundance of target bed are Bao No.1 section, Da No.1 section and Wuyun Formation, Xin-Ancun Formation secondly, Bao No.2 section and Cretaceous thirdly. The organic matter maturity becomes big with the increasing depth. According to the tracing contrast of the source rock, lacustrine-facies pelite of Da Lianhe Formation and Xin Ancun Formation is the major types of source rocks of lake oil, while coal measure strata of Xin Ancun Formation and Wuyun Formation is the major types of source rocks of coal oil. The mudstone of Bao Quanling Formation No. one section and Cretaceous is the potential source rock. The reservoir lithology of Tangyuan fault depression are mainly unequal sandstone, hybrid sandstone, sandy conglomerate and lithic arkose, and its physical properties belongs to medium porosity and medium permeability. The source reservoir cap assemblage can be divided into three main types of self-generating and self-accumulating,top reserveior-bottom source,and new-generating and old-accumulating..The total volume of oil resource and gas resource of Tangyuan fault depression are respectively 0.952～2.509×10~8 tons and 469.6×10~8 stere. The resource prospect is considerable. After analyzing comprehensively the geological condition of oil and gas, the paper forecasts the favorable exploration belt and points out the exploration direction of the next step.更多还原