塔中顺南奥陶系热液作用及热液成因储层研究

发布时间：2019-03-08 14:25

【摘要】：本次论文研究在前人研究的基础上,综合钻井测井资料、岩芯及薄片观察,总结认识研究区中下奥陶统储层主要储集岩石类型、成岩作用特征,并建立相应的成岩演化序列。研究区热液成因储集岩主要包括微晶灰岩、颗粒灰岩、藻粘结灰岩、白云岩以及硅化硅质岩。研究区发育多种成岩作用,包括对储层形成具有促进作用的白云石化作用、硅化作用、溶蚀作用、岩溶作用及破裂作用等,对储层的形成具有阻碍作用的胶结作用、压实压溶作用、黄铁矿化作用等。结合岩石学特征及地球化学分析,分析区内白云石化和硅化作用机制并建立模式。根据各类白云石特征,将区内白云岩分为粉-微晶白云石、粉-细晶它形脏白云石、粉-细晶自形白云石、中-粗晶白云石以及鞍状白云石,区内白云石经历了四期不同类型的白云石化作用,包括同生期高盐度海水白云石化作用、早成岩期浅埋藏白云石化作用、早成岩期热液白云石化作用、晚成岩期热液白云石化作用,热液白云石化作用对热液储层的形成具有重要意义。研究区发育两期硅化作用,早期硅化作用以硅化硅质结核或条带为特征,对储层发育起阻碍作用;晚期硅化发育较为广泛,以石英交代及自形石英生长为特征,硅化作用的发育与二叠纪富硅热液流体关系密切,晚期硅化作用形成的溶蚀孔隙和未完全充填不规则裂缝是热液成因储层重要的储集空间。结合前期工作,对区内热液流体期次及作用机制模式进行总结。区内存在两期热液作用,分别是晚奥陶世-志留纪的第I期热液作用以及二叠纪的第II期热液作用。晚奥陶世-志留纪的第I期热液作用主要表现为阴极发光发暗玫瑰红色光或近于不发光的多种形式的中-粗晶白云石发育,此期热液作用流体来自地下深处,与中酸性岩浆活动有关,在压实作用与断裂系统共同驱动之下,在研究区分布范围较大。二叠纪的第II期热液作用主要表现为发亮红色光的溶蚀孔洞鞍状白云石、硅化长柱状石英晶体生长等特征,此期热液流体是一期富硅的岩浆期后流体,主要受断裂系统控制。区内热液成因储层储集空间类型主要有溶蚀孔隙、溶蚀孔洞以及热液溶蚀不规则裂缝,储层类型主要有有灰岩热液溶蚀孔洞型储层和硅化硅质岩热液溶蚀型储层两类类。灰岩热液溶蚀孔洞型储层是区内主要的热液成因储层,现有资料揭示此类储层主要分布于一间房组,储集岩为颗粒灰岩及微晶灰岩,储集空间为溶蚀孔洞,储层发育分布显示出一定受断裂控制的特征。硅化硅质岩热液溶蚀型储层见于顺南4井及顺南401井鹰山组上段,储集空间为长柱状石英晶体粒间溶蚀孔隙及未完全充填的不规则缝洞,储层的发育分布受断裂控制,尤其在断裂拉分段更为发育。
[Abstract]:On the basis of previous studies, this paper summarizes the main reservoir rock types and diagenetic characteristics of the middle and lower Ordovician reservoirs in the study area, and establishes the corresponding diagenetic evolution sequence based on the drilling logging data, core and thin slice observations. Hydrothermal reservoir rocks include microcrystalline limestone, granular limestone, algae-bonded limestone, dolomite and silicified siliceous rocks. Various diagenesis has been developed in the study area, including dolomitization, silicification, dissolution, karstification and fracture that promote the formation of reservoirs, which have hindered the formation of reservoirs. Compaction pressure solution, Huang Tie mineralization, etc. Combined with petrological characteristics and geochemical analysis, the mechanism of dolomitization and silicification in the area is analyzed and a model is established. According to the characteristics of various dolomites, the dolomites in the area are divided into powder-microcrystalline dolomite, powder-fine-grained dirty dolomite, powder-fine-grained self-shaped dolomite, medium-coarse-grained dolomite and saddle-shaped dolomite. The dolomite in the area has experienced four stages of dolomitization, including high salinity dolomitization in syngenetic period, dolomitization in early diagenetic period and hydrothermal dolomization in early diagenetic period. The hydrothermal dolomitization in late diagenetic period is of great significance to the formation of hydrothermal reservoirs. There are two stages of silicification in the study area, and the early silicification is characterized by siliceous nodules or bands, which hinders the development of reservoirs. The development of silicification is extensive, characterized by quartz metasomatism and self-shaped quartz growth. The development of silicification is closely related to the Permian silicon-rich hydrothermal fluid. Corrosion pores and incomplete filling irregular fractures formed by late silicification are important reservoir spaces for hydrothermal reservoirs. Combined with the previous work, the period of hydrothermal fluid in the area and the model of action mechanism were summarized. There are two periods of hydrothermal interaction in the area, namely the late Ordovician-Silurian stage I hydrothermal action and Permian stage II hydrothermal action. The hydrothermal action in the late Ordovician-Silurian stage I was mainly characterized by dark cathodolescent rose-red light or various forms of medium-coarse-grained dolomite near non-luminous, during which the hydrothermal fluid came from the depth of the ground. It is related to intermediate-acid magmatic activity. Driven by compaction and fault system, it is widely distributed in the study area. The hydrothermal action in Permian stage II is mainly characterized by bright red-light solute hole saddle dolomite and silicified columnar quartz crystal growth. The hydrothermal fluid in this period is a post-magmatic fluid with rich silicon, which is mainly controlled by the fracture system. The hydrothermal fluid in Permian is characterized by bright red-light dissolved holes, saddle-shaped dolomite and silicified long-columnar quartz crystal growth. The reservoir space types of hydrothermal origin reservoirs in this area are mainly corrosion pores, corrosion holes and hydrothermal corrosion irregular fractures. The reservoir types mainly include limestone hydrothermal solution pore type and siliceous rock hydrothermal solution type reservoir, which are mainly composed of two types: limestone hydrothermal solution pore type reservoir and siliceous rock hydrothermal solution type reservoir, which are mainly composed of limestone hydrothermal solution pore type and siliceous rock hydrothermal solution type reservoir. Limestone hydrothermal solution pore type reservoir is the main hydrothermal origin reservoir in this area. The existing data show that this type of reservoir is mainly distributed in a chamber formation, the reservoir rock is granular limestone and microcrystalline limestone, and the reservoir space is dissolved pore. The reservoir development and distribution shows the characteristics that are controlled by faults. The hydrothermal corroded reservoirs of siliceous rocks are found in the upper section of Yingshan formation in wells Shunnan 4 and Shunnan 401. The reservoir spaces are long columnar intergranular dissolution pores and irregular fracture holes that are not fully filled, and the development and distribution of the reservoirs are controlled by faults. Especially in the fracture tensile segment is more developed.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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