鄂尔多斯地区中上元古界分布与沉积环境及其油气勘探潜力

发布时间：2019-04-17 10:29

【摘要】：随着国内外中上元古界油气藏,尤其是鄂尔多斯盆地西南缘蓟县系沥青和盆地北部伊盟隆起区长城系内天然气的发现,使得鄂尔多斯地区中上元古界日益成为一个值得关注的潜在油气勘探领域。鄂尔多斯地区地处华北克拉通西部,区内中上元古界不整合覆盖于吕梁运动固结的克拉通结晶基底之上。其分布广泛,无明显变质。然而,以往油气勘探侧重于中古生界,对中上元古界的各项研究甚少,致使其研究十分薄弱。为搞清鄂尔多斯地区中上元古界油气勘探潜力,本文在系统整理、总结前人研究成果的基础上,通过野外考察、剖面实测,辅以分析测试,结合测井数据、钻井岩心和最新地震大剖面及重磁等资料,对研究区中上元古界地层划分与分布特征、沉积相及其演化进行了综合研究,并预测有利勘探潜力区。取得了以下认识：(1)在锆石U-Pb年龄测试及前人研究成果分析基础上,确定黄旗口组、汝阳群、海原群属于长城系,王全口组属于蓟县系,制定了鄂尔多斯盆地及其周缘中上元古界地层划分与对比方案,绘制了长城系、蓟县系及震旦系分布图。(2)运用测井、地震及地化测试资料,结合野外观察等成果,对研究区中上元古界沉积相及沉积环境进行了分析,结果显示：熊耳群为海陆交互沉积环境；高山河群为潮坪相沉积；黄旗口组为滨海-泻湖相沉积；洛南群和王全口组为碳酸盐台地潮坪相沉积；白术沟组为滨海-浅海陆棚相；罗圈组和正目关组为滨海-冰川相沉积。(3)依据评价标准,结合有机地化测试分析数据,对盆地南缘中上元古界烃源岩及有利区进行了评价：长城系和震旦系泥岩为差烃源岩,有一定生烃潜力；蓟县系海相碳酸盐岩为差-中等烃源岩,具备一定生烃能力；白术沟组泥质岩为非烃源岩。(4)结合中上元古界分布及成藏组合分析,划分出油气勘探有利区,并将其划分为上生下储型、蓟县系自生自储型及长城系自生自储型3类。
[Abstract]:With the discovery of middle and upper Proterozoic oil and gas reservoirs at home and abroad, especially Jixian bitumen in the southwest margin of the Ordos Basin and natural gas in the Great Wall system in the Yimeng uplift area in the northern part of the basin, The Middle and Upper Proterozoic in Ordos area is becoming a potential oil and gas exploration field. Ordos area is located in the western part of North China craton, where the Middle and Upper Proterozoic unconformities cover the craton crystalline basement consolidated by Lv Liang movement. It is widely distributed and has no obvious metamorphism. However, in the past, oil and gas exploration focused on the Middle Palaeozoic, and few studies on the Middle and Upper Proterozoic have been made, which leads to the weak study of the Middle and Upper Proterozoic. In order to understand the oil and gas exploration potential of Middle and Upper Proterozoic in Ordos area, this paper, on the basis of systematical arrangement and summary of previous research results, through field investigation, profile measurement, analysis and test, combined with logging data, The classification and distribution characteristics, sedimentary facies and evolution of the Middle and Upper Proterozoic strata in the study area were comprehensively studied by drilling cores and the latest seismic profiles, gravity and magnetic data, and the favorable exploration potential areas were predicted. The following knowledge is obtained: (1) on the basis of zircon U-Pb age test and previous research results, the Huangqikou formation, Ruyang Group, Haiyuan Group belong to the Great Wall system and Wang Quankou formation belong to Jixian system. The division and correlation scheme of Middle and Upper Proterozoic strata in Ordos Basin and its periphery are drawn up, and the distribution maps of Great Wall system, Jixian system and Sinian system are drawn up. (2) using logging, seismic and geochemical test data and field observation, etc. The sedimentary facies and environment of the Middle Proterozoic in the study area are analyzed. The results show that Xionger Group is a sea-land interactive sedimentary environment; Gaoshanhe Group is tidal flat facies, Huangqikou formation is coastal-lagoon facies, Luonan Group and Wangchuankou formation are carbonate platform tidal flat facies, Baizhugou formation is coastal-shallow shelf facies, and Huangqiankou formation is coastal-lagoon facies, and Huangqankou formation is coastal-lagoon facies. The looping formation and Zhengmuguan formation are coastal-glacier facies sediments. (3) according to the evaluation criteria, combined with the organic geochemical test and analysis data, The middle and upper Proterozoic source rocks and favorable areas in the southern margin of the basin are evaluated. The mudstones of the Great Wall system and the Sinian system are poor source rocks with a certain hydrocarbon generation potential. Jixian marine carbonate rocks are poor-medium hydrocarbon source rocks, and have a certain hydrocarbon generation capacity. The mudstone of the Baizhugou formation is a non-hydrocarbon source rock. (4) combined with the distribution of the Middle and Upper Proterozoic and the analysis of the pool-forming assemblages, the favorable areas for oil and gas exploration are divided into three types: the upper generation and the lower reservoir type, the Jixian system self-generating type and the Great Wall system self-generating type.
【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】：P618.13

【参考文献】