鄂尔多斯盆地南部太原组—山西组沉积相及页岩气勘探潜力研究

发布时间：2018-06-27 06:54

  本文选题：页岩气 + 太原组　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：鄂尔多斯盆地是我国最重要的大型海陆过度相沉积盆地之一。近年来随着我国对天然气的勘探开发力度加深,鄂尔多斯盆地北部已经发现了苏里格、榆林等大型上古生界气田,然而对鄂尔多斯盆地南部上古生界地层的研究尚处于薄弱阶段,且以往的研究主要集中在常规油气资源和煤层气方向,极大的制约了鄂尔多斯盆地页岩气的勘探开发。本文以沉积学和烃源岩生烃理论为指导,对鄂尔多斯盆地南部太原组、山西组展开研究,提出了鄂尔多斯盆地南部太原组、山西组有利泥页岩储层的形成环境、成藏特点。太原组、山西组是鄂尔多斯盆地上古生界主要含泥页岩层段。根据对研究区野外实测剖面和收集到的钻井柱状图,识别出研究区太原组、山西组主要发育河流相、湖泊相、三角洲相、障壁海岸相和浅海陆棚相共5种沉积相和河漫亚相、浅湖亚相、三角洲平原亚相、三角洲前缘亚相、障壁岛亚相、泻湖亚相、潮坪亚相和碳酸盐台地亚相共8种沉积亚相。研究区泥页岩分布广泛,太原组以永和、环县为东西两个沉积中心相研究区中部以此减薄;山西组上段和山西组下段则以这两个沉积期的湖泊为沉积中心,向南北两侧减薄。研究区泥页岩有机质丰度(TOC)总体含量较高,样品中TOC在1%以上的超过75%。通过元素分析表明研究区泥页岩干酪根类型主要为Ⅱ1型(腐殖腐泥型)、Ⅱ2型(腐泥腐殖型)还有少量的Ⅲ型,具有很好的生气潜力。鄂尔多斯盆地南部太原组、山西组地层的有机质镜质体反射率(Ro)集中在0.8%~2.0%,大部分属于高成熟阶段。对研究区样品X衍射分析表明,太原组、山西组泥页岩主要以蒙脱石、伊利石、绿泥石等粘土类矿物和石英、长石等脆性矿物为主;且研究区泥页岩孔隙发育程度高,连通性较好,渗透率极低,可以作为页岩气的优良储层。本文通过对研究区泥页岩岩样有机质含量、成熟度、有机质类型和孔隙度、渗透率的研究和研究区沉积相的研究,总结出了泥页岩发育规律,完成了鄂尔多斯盆地南部有利区域的优选,同时为下一步鄂尔多斯盆地的上古生代页岩气开发提供理了论依据。
[Abstract]:Ordos Basin is one of the most important marine and continental transitional sedimentary basins in China. In recent years, with the deepening of natural gas exploration and development in China, large Upper Paleozoic gas fields, such as Sulige and Yulin, have been discovered in the northern part of the Ordos Basin. However, the study of Upper Paleozoic strata in the south of Ordos Basin is still in a weak stage, and previous studies mainly focus on conventional oil and gas resources and the direction of coalbed methane, which greatly restricts the exploration and development of shale gas in Ordos Basin. Guided by sedimentology and hydrocarbon generation theory of source rocks, this paper studies Taiyuan formation and Shanxi formation in the south of Ordos Basin, and puts forward the forming environment and reservoir forming characteristics of shale-forming reservoirs in Taiyuan formation and Shanxi formation in the south of Ordos basin. Taiyuan formation and Shanxi formation are the main shale-bearing member of Upper Paleozoic in Ordos Basin. Based on the field measured profiles and the well drilling histogram collected in the study area, five sedimentary facies and river subfacies were identified in Taiyuan formation and Shanxi formation in the study area, which mainly developed fluvial facies, lacustrine facies, delta facies, barrier coast facies and shallow sea shelf facies. There are 8 sedimentary subfacies including shallow lake subfacies delta plain subfacies delta front subfacies barrier island subfacies lagoon subfacies tidal flat subfacies and carbonate platform subfacies. The mud shale is widely distributed in the study area, the middle part of the study area of Yonghe and Huanxian is the east and west sedimentary center facies, and the upper part of Shanxi formation and the lower part of Shanxi formation take the lake of these two sedimentary periods as the sedimentary center, thinning to the north and south sides. The total content of organic matter abundance (TOC) of shale in the study area is higher than 75% in the samples with TOC above 1%. The element analysis shows that the kerogen types of shale in the study area are mainly type 鈪，

本文编号：2073069