南堡凹陷古近系泥页岩孔隙结构特征及影响因素

发布时间：2018-07-15 16:31

【摘要】：南堡凹陷泥页岩油气成藏的研究处于起步阶段,油气的赋存方式及勘探潜力尚不明确。本文综合利用大量的基础地质资料,针对泥页岩的岩性分布、矿物学特征、微观孔隙特征及吸附性等特征展开工作,意在弄清其页岩储层的微观孔隙结构特征及其影响因素,以期来指导下一步研究区泥页岩油气资源的勘探开发。通过借鉴前人对于泥页岩的研究方法和成果,广泛搜集包括钻井资料、录井资料、测井资料、地层数据等资料,并对大量岩心样品进行了实验分析测试,所采取的实验手段包括:低温液氮吸附实验、甲烷等温吸附实验、X-RD衍射全岩鉴定、电感耦合等离子体原子光谱、扫描电镜、元素能谱等。研究显示南堡凹陷古近系泥页岩空间展布总体上具有分布广、厚度大的特点,岩相类型可划分为三大类五小类,特定的岩相在测井曲线上有明显的响应特征。全岩矿物组成与Marellus页岩和Haynesville页岩具有较好的可比性。本地区泥页岩孔隙类型可以分为有机质孔、粒间孔、粒内孔以及微裂缝。孔隙形态复杂,有细颈长体的墨水瓶形、有四面开放的平行板形及尖劈形,以利于储集气体的墨水瓶型为主。从孔径来看,广泛发育有微孔和介孔,其中介孔提供了主要的孔体积,微孔和介孔提供了主要的比表面。有机碳含量是控制南堡凹陷古近系泥页岩中孔容及比表面积的主要因素;石英和方解石与孔体积有较好的相关性;脆性矿物对于孔隙有积极的建设作用,黏土矿物对孔隙的贡献有限;有机质热演化过程中形成的有机酸会对长石、方解石等不稳定矿物形成溶蚀作用,但是其增孔能力有限;影响泥岩裂缝形成的机制主要有构造运动、沉积及成岩作用和地层超压。有机碳含量是控制泥页岩甲烷吸附能力的主要因素;成熟度与页岩吸附能力的关系尚不清楚;以伊蒙混层和伊利石为主的粘土矿物与吸附气含量呈正相关,而以方解石为主的碳酸盐矿物与吸附气量呈负相关。
[Abstract]:The study of shale oil and gas accumulation in Nanpu sag is still in its infancy, and its occurrence mode and exploration potential are not clear. Based on a large amount of basic geological data, this paper aims at studying the lithologic distribution, mineralogical characteristics, microscopic pore characteristics and absorbability of shale in order to find out the microscopic pore structure characteristics of shale reservoir and its influencing factors. In order to guide the exploration and development of shale oil and gas resources in the next research area. By drawing lessons from the previous research methods and achievements on shale, we extensively collected data including drilling data, logging data, formation data and so on, and carried out experimental analysis and test on a large number of core samples. The experimental methods are as follows: low temperature liquid nitrogen adsorption experiment, methane isothermal adsorption experiment, X-ray diffraction identification, inductively coupled plasma atomic spectrum, scanning electron microscope, elemental energy spectrum and so on. The study shows that the spatial distribution of Paleogene shale in Nanpu Sag has the characteristics of wide distribution and large thickness. The lithofacies types can be divided into three types and five subclasses, and the specific lithofacies have obvious response characteristics on logging curves. The mineral composition of the whole rock is comparable to that of Marellus shale and Haynesville shale. The pore types of shale in this area can be divided into organic pore, intergranular pore, intragranular pore and microfracture. The pore shape is complex, with a thin neck, a long body of ink bottle shape, four sides of the parallel plate shape and split shape, in favor of the storage of gas in the ink bottle type. From the pore size point of view, there are many micropores and mesoporous cells, which provide the main pore volume, micropore and mesopore provide the main specific surface. Organic carbon content is the main factor controlling pore volume and specific surface area of Paleogene shale in Nanpu Sag, quartz and calcite have good correlation with pore volume, brittle minerals have positive effect on pore construction. The contribution of clay minerals to pores is limited, organic acids formed during the thermal evolution of organic matter form dissolution of unstable minerals such as feldspar and calcite, but their pore increasing capacity is limited. The main mechanisms affecting the formation of mudstone fractures are tectonic movement, sedimentation and diagenesis, and formation overpressure. The content of organic carbon is the main factor to control the adsorption ability of shale methane, the relationship between maturity and shale adsorption ability is not clear, and the clay minerals, which are mainly Illite and Illite, have a positive correlation with the adsorption gas content. The calcite-based carbonate minerals are negatively correlated with the amount of gas adsorbed.
【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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