【作者】 王震；

【导师】 郭少斌；

【作者基本信息】 中国地质大学(北京) ， 石油与天然气工程， 2013， 硕士

【摘要】 鄂尔多斯盆地可划分为六个一级构造单元,即北部伊盟隆起,西缘断褶带,西部天环坳陷,中部陕北斜坡,南部渭北隆起和东部晋西挠褶带。研究区位于湖盆中心,构造上属于鄂尔多斯盆地伊陕斜坡区,西临天环坳陷带,南近渭北隆起。中生界晚三叠世延长组主要为一套灰绿色、灰色中厚层粉细砂岩、粉砂岩和深灰色,灰黑色泥页岩沉积。下部以河流中、粗砂岩沉积为主,中部为一套湖泊—三角洲为主砂泥互层沉积,上部为河流相砂泥页岩沉积。延长组与其上下相邻地层为平行不整合接触。延长组沉积旋回性很强,自下而上划分五个段,各段之间均为连续性沉积。后为适应油气勘探需要,按岩性、电性,特别是根据十个标志层(K0-K9)将其自上而下分为十个油层组。本区主要油层长7根据沉积旋回和标志层进一步分为长73、长72、长71等次一级含油层组。长7三个层的砂体厚度自下而上依次增大,其中长73砂体较71和72要薄很多,砂层数目也较少。长7泥页岩段样品的有机质丰度较高。干酪根样品的镜下观察表明,泥页岩中的有机质以无定型藻类为主,浮游藻类和底栖藻类是长7泥页岩的主要生物来源。干酪根类型以Ⅱ1和Ⅱ2型为主。研究区Ro主要为0.56%—1.12%,平均0.83%。属于生油的低成熟-成熟阶段。研究区泥页岩含油率较低,仅为0.26%—4.69%,平均为1.15%,推测泥页岩出现过大规模的生烃和排烃,没有大规模的页岩油区带。长7泥页岩脆性矿物比较发育,各层含量都超过40%。脆性指数和北美相比,相对较高。泥页岩孔隙度主要在0.5%-2%之间,渗透率主要在(1-7)× 10-6μm2之间。研究区油藏以岩性油藏为主,长7本身集生、储、盖为一体。砂体形态以及砂体与泥页岩的接触关系影响着长7的油藏分布。对长7三个层页岩油有利目标预测图进行比较,发现长73泥页岩有利区比长71和长72的面积较大,初步说明长73勘探页岩油气较为有利。更多还原

【Abstract】 Ordos Basin Can be divided into six 1st tectonic units.Yimeng uplift in the north,The folded zone in the western margin,Tianhuan Depression in the west,Shanbei Slope in the center,Weibei uplift in the south and Jinxi flexure with in the east.The study area is located in the center of the basin,belongs to the Yixia Slope of Ordos Basin,the west is Tianhuan Depression and the south is near with the Weibei uplift.Yanchang Formation in late Triassic epoch of Mesozoic is a set of gray-green,gray Medium-bedded of fine sandstone,siltstone and dark gray,black shale deposition.The Lower part consists mostly of medium and coarse sandstone sediments,the middle part is a set of Lake-Delta sand and mud interbedded sedimentary,the upper part is fluvial sandstones and mudstones sediments.The Yanchang Formation’s top of each other strata is a parallel unconformity.It has Obvious Sedimentary cycles,Bottom-up is divided into five segments,between the various sections are continuous deposition.In order to meet the needs of oil and gas exploration,By lithology,electrical properties,especially in light of the 10 marker bed(K0-K9),Yanchang Formation is divided into 10 reservoir group from top to bottom.Depend on sedimentary cycles and logo layer,chang 7 is divided into chang 73.chang 72 and chang 71 oil layer group.Sand thickness of the three layers is increases from bottom to top,chang 73 is much thinner compared to chang 71 and chang 72,the sand is also small.The abundance of organic matter of chang 7 shale is high.The kerogen microscopic observations suggest that organic matter in the shale consists mostly of amorphous algae,planktonic algae and benthic algae are the most biological sources of chang 7 shale.Kerogen types are Ⅱ1 and Ⅱ2,Ro in the study area is 0.56%—1.12%,0.83%in average.The oil generation is at Low-mature and mature stage.Shale oil content in the study area is lower,only 0.26%—4.69%,1.15%in average.Speculate that shale there have been have a large-scale hydrocarbon and hydrocarbon expulsion,and there is no large-scale shale oil zone.There is much brittle mineral in chang 7 shale,the content of each layer is more than 40%.The brittle index is relatively high compared to North America.The shale porosity is 0.5%-2%,and the permeability is(1-7)×10-6μm2.The reservoir of study area is lithology reservoir,chang 7 is the Source rocks,Reservoir and also the cover.The sand morphology and sand contaction with shale impact chang 7 reservoir distribution.It is more favorable to explorate shale oil and gas in chang 73.更多还原