柴达木盆地北缘东段克鲁克组泥页岩岩相及储层特征研究

发布时间：2018-03-09 04:31

本文选题：岩相　切入点：储层　出处：《中国石油大学(华东)》2015年硕士论文　论文类型：学位论文

【摘要】：为深入了解柴达木盆地北缘(柴北缘)东段石炭系克鲁克组泥页岩油气地质基本特征,本文主要运用沉积学、储层地质学和油气地球化学等理论,采用野外地质剖面踏勘和实测、岩心精细观察描述及室内实验分析方法对泥页岩的岩相及储层特征进行了研究,取得的成果如下。通过野外剖面踏勘和实测,对柴北缘东段石炭系克鲁克组泥页岩纵向发育特征进行了研究,结果表明克鲁克组泥页岩发育状况良好,累计厚度大于360m,其中克一段泥页岩厚60m、泥地比达92.6%,是泥页岩发育最好的层段。岩石薄片鉴定及全岩X射线衍射分析结果表明,柴北缘东段克鲁克组泥页岩矿物组成以石英和粘土矿物为主,粘土矿物主要为伊蒙混层矿物;岩石平均粒度为中粉砂-粗粉砂级;沉积构造以潮汐层理、块状层理、同沉积变形构造和成岩结核构造为主。综合泥页岩的平均粒度、层理构造、颜色和碳酸盐含量特征,将克鲁克组泥页岩划分为黑色纹层状泥质中粉砂岩相、灰黑色条带状泥质粗粉砂岩、灰黑色条带状含灰-灰质泥质粗粉砂岩相和黑色纹层状含生物碎屑泥质中粉砂岩相等6种岩相类型。泥页岩主要发育在潮坪、泻湖及局限台地环境中,频繁的古水深变化引起的沉积环境改变是形成不同类型岩相的主要原因。克鲁克组泥页岩成岩作用类型主要有压实作用、碳酸盐胶结作用、交代作用和粘土矿物转化作用,岩石整体处于中成岩A2-B演化阶段。泥页岩孔隙度在0.69%~5.55%之间,均值为2.1%,渗透率在0.01~2.21mD之间,均值为0.39mD;储集空间分为孔隙和裂缝两种类型,其中孔隙包括粘土矿物晶间孔、有机质粒内孔、生物碎屑粒内孔和溶蚀孔隙,裂缝包括顺层裂缝、构造裂缝、异常压力缝和有机质粒内缝。黑色纹层状泥质中粉砂岩相和灰黑色条带状泥质粗粉砂岩相由于单层厚度较大、有机质含量高、脆性强、储集性能良好,是有利的岩相类型。持续稳定的潮坪环境可形成较大厚度、连续的泥页岩沉积,是有利岩相发育的基础;相对较高的石英含量提高了泥页岩的脆性,是有利岩相发育的重要因素;成岩作用对于有利岩相发育的影响具有两面性,较高的有机质热演化程度有利于有机质粒内孔(缝)和溶蚀孔隙的形成,对有利岩相的形成有利,碳酸盐的致密胶结对于孔隙和裂缝具有充填破坏作用,不利于有利岩相的形成。
[Abstract]:In order to understand the basic characteristics of shale oil and gas geology of Carboniferous Kruke formation in the eastern section of the northern margin of Qaidam Basin (northern margin of Qaidam Basin), this paper mainly uses the theories of sedimentology, reservoir geology and oil and gas geochemistry, etc. In this paper, the lithofacies and reservoir characteristics of shale are studied by means of field geological profile exploration and measurement, core fine observation description and laboratory experimental analysis. The results obtained are as follows. The longitudinal development characteristics of Carboniferous mud shale of Kruke formation in the eastern part of the northern margin of Qaihai are studied. The results show that the mud shale of the Kruke formation is developing well. The accumulative thickness is more than 360 m, in which the shale of Ke Yi section is 60 m thick, and the mud ground is 92.6 m, which is the best section of shale development. The identification of rock slice and X-ray diffraction analysis of the whole rock show that, The shale minerals of the Kruke formation in the eastern part of the northern margin of Qaidam are mainly composed of quartz and clay minerals, the clay minerals are mainly immonitic minerals, the average granularity of the rocks is medium silty sand and coarse silt grade, the sedimentary structure is tidal stratification and block bedding, According to the characteristics of average grain size, bedding structure, color and carbonate content of shale shale, the clay shale of Kruke formation can be divided into siltstone facies with black grain layer and mudstone, which is mainly composed of sedimentary deformed structure and diagenetic nodule structure, and is characterized by its average grain size, bedding structure, color and carbonate content. The gray-black striped muddy coarse siltstone, the gray-black banded gray-lime-argillaceous coarse siltstone facies and the black laminated bioclastic mudstone are equal to six lithofacies types. In lagoon and confined platform environment, the sedimentary environment change caused by frequent paleodepth change is the main reason for the formation of different types of lithofacies. The shale diagenesis types of Kruke formation are mainly compaction and carbonate cementation. In metasomatism and clay mineral transformation, the whole rock is in the A2-B evolution stage of middle diagenesis. The porosity of shale is between 0.69% and 5.55%, the mean value is 2.1%, the permeability is 0.01mD and the average value is 0.39mD. the reservoir space is divided into two types: porosity and fracture. The pores include intergranular pores of clay minerals, intergranular pores of organic matter, inner pores of bioclastic grains and dissolved pores, and fractures include bedding fractures and structural fractures. Abnormal pressure fractures and organic plasmids. The siltstone facies and the gray-black stripe muddy coarse siltstone facies in the layer of black grain are characterized by large monolayer thickness, high organic matter content, strong brittleness, and good reservoir properties. The relatively high quartz content increases the brittleness of shale, which is the basis of favorable lithofacies development, which can be formed in a stable tidal flat environment with large thickness and continuous mud shale deposition, and a relatively high quartz content increases the brittleness of mudstone shale, and a relatively high quartz content increases the brittleness of shale. Diagenesis has a dual effect on favorable lithofacies development. A higher degree of thermal evolution of organic matter is favorable to the formation of organic matter inner pores (fractures) and dissolution pores, and favorable to the formation of favorable lithofacies. The dense cementation of carbonate has the effect of filling and destroying the pores and fractures, which is not conducive to the formation of lithofacies.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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