【作者】 任宪军；

【导师】 王岫岩；

【作者基本信息】 大庆石油学院 ， 矿产普查与勘探， 2008， 硕士

【摘要】 本文综合采用层序地层学、沉积岩石学、地震地层学等最新的理论和方法,运用地震、测井、录井、岩心等分析资料,对本研究区的层序地层格架、沉积相类型及其演化规律、烃源岩的地球化学特征、储层及盖层的分布特征等进行了精细的分析和研究。明确冷湖和南八仙地区有效烃源岩的分布、典型油气藏的地质特征及油气成藏的主控因素,进一步表明大中型油气田的勘探方向,对柴达木盆地北缘地区的目的区块的优选,目的层位的确定,起到积极的意义。下侏罗统残余陆相断陷沉积构成主要的烃源岩系,第三系挤压坳陷型沉积为主要运聚体系。其中,中始新统的区域性泥质盖层控制油气的垂向运聚,该盖层的下伏层系中油气以侧向运聚为主,其上仅在局部受断层贯通形成的运移通道出现油气集中垂向运移,具有双层运聚模型。系统从渐新世早期开始初步建立,渐新世早期为原生油气藏形成期,上新世早期为次生油气藏及干气气藏形成期,在第四纪的早期进人保存关键时期。对该地区的地面、井下岩性和岩相进一步研究表明,自下干柴沟组至下油砂山组的储集砂体主要为滨-浅湖滩坝亚相和湖泊三角洲相。柴达木盆地北缘侏罗系含油气系统具有巨厚的下侏罗统湖相泥岩和中侏罗统煤系地层。烃源岩有机质丰度高,有机质类型主要为Ⅱ~Ⅲ型,生烃期集中在J3~K、E32~N23;本地区既有中生代古隆起,又有新生代构造运动形成的一系列构造圈闭(褶皱)和油气运移通道(断层),在侏罗系和第三系具有多套储盖组合。冷湖一号至五号勘探区带、南八仙-大红沟古隆起勘探区带及赛什腾山前勘探区带是今后柴达木盆地北缘最现实的三大有利勘探区带。更多还原

【Abstract】 Using the latest theories and methods,such as, Sequence stratigraphy, Sedimentary petrology, Seismic stratigraphy, and applicating seismic, logging, core data, this text does fine analysis and research on sequence stratigraphic framework, sedimentary facies types and evoluting rule, geochemical features of hydrocarbon rock, pattern of reservoir and capping formation. So there is a conclusion about distribution of valid mother rock, geological feaure of typical reservoir, and main factors of oil/gas playing reservior in Lenghu and Nanbaxian area, further indicating the exploration direction of large and medium size field, objective block optimization in the northern of Qaidam basin and confirm object horizon, having a constructive meaning.Main source rocks are composed of relict lacustrine fault-depression sediments of Lower Jurassic;Tertiary compressive depression deposits form the major migrating and accumulating system. The vertical migrating and accumulating are controlled by a regional. pelitic caprock of the Middle Eocene,below which,the migration and accumulation of oil-gas are mainly happened in lateral direction and vertical migrating of oil-gas only appears in layer above the capping because a migrating pathway is formed by local fault,where a double layer type can be detected within the system. The system had been primarily formed from early Oligocene which a period of forming primary oil-gas pools. A secondary oil-gas pools and dry-gas pools should be formed at the early pliocene,and the key preservation stage came during the early Quaternary.A comprehensive study on petrology, structures, facies models, facies associations and sedimentary systems in this paper shows that the main facies in Tertiary are shore-lake and shallow-lake subfacies, and lake delta facies from low-Gancaigou formation to low-Youshashan formation.Lower-Middle fresh lacustrine shale and coalmeasures with huge thickness have been found in the petroleum system of the northern Qaidam basin. These source rocks are characterized by high abundance of organic matter with mainly typeⅡ~Ⅲ. The major oil and gas generation stage of the Jurassic source rocks is between J3~K、E32~N23. At that time, the existing Mesozoic paleo-uplifts and the Cenozic folds and faults, which served as oil migration routes and traps, greatly promoted the oil reservoir formation. In addition, multiple reservoir-cap compositions are confirmed in both the Jurassic and Tertiary strata.So far, Great potential for further hydrocarbon exploration remains in this area. Three preferential targets for future hydrocarbon exploration are selected, .i e. Lenghu No. 1 to No. 5 Trap, Nanbaxian-Dahonggou paleo uplift and the front of Saishiteng mountain.更多还原