摘要
滴西18井区广泛分布的次火山岩是克拉美丽气田石炭系火山岩油气藏重要的储集岩,次生溶蚀孔隙及构造裂隙是其主要的储集空间类型。在岩心观察与描述基础上,通过铸体薄片鉴定、化学元素分析、扫描电镜观察以及阴极发光分析等,探讨次火山岩储层储集空间发育的控制因素及演变规律,为我国类似火山岩储层形成机理研究提供理论依据。结果表明,次火山岩原生储集空间的形成主要受到侵入期岩浆冷凝作用的控制,次生储集空间的形成主要受构造期风化淋滤作用以及埋藏期成岩作用的控制。岩浆侵入围岩时期是原生储集空间形成的主要时期,火山岩岩相分布决定了原生储集空间展布位置,是形成优质储层的基础。构造期是次生储集空间形成的主要时期,构造作用形成的裂缝沟通岩体与大气环境形成开放体系,裂缝发育带是有利储层分布带,火山岩所处的构造位置决定了裂缝的发育程度。埋藏期系统处于封闭体系,是储集空间重新分布的主要时期,成岩作用改变储层三维空间展布位置,酸性流体的溶蚀作用及后期充填作用,导致火山岩体内部储层非均质性明显。
Subvolcanic rocks are widely distributed in the well Dixi 18 area which is the most important reservoir rocks for the Carboniferous volcanic gas reservoirs in Kelameili Gasfield,of which secondary dissolution pores and tectonic fissures are the main reservoir space.Based on the observation and description of cores,this study conducted casting thin section,chemical element analysis,scanning electron microscope and cathode luminescence analysis to examine the controlling factors and the evolution governing laws,space development in the subvolcanic reservoir.This provides a theoretical basis for studies of the formation mechanisms of similar volcanic reservoirs in China.Formation of primary spaces is mainly controlled by magmatic condensation in the magmatic intrusive stage,while formation of secondary pore spaces is controlled by weathering and leaching process in the tectonic stage and deep burial diagenesis.The spatial location of the primary spaces produced in the magmatic intrusive stage is determined by the distribution of volcanic facies.Volcanic facies are the basis for high-quality reservoirs.The tectonic stage is the main time when secondary pores are formed and fractures are formed under tectonism,connecting rocks with the atmosphere to form an open system environment.The fracture zone is a favorable reservoir distribution belt,and the structural position of volcanic rocks determines the development of fractures.The system became a closed system during the burial stage,which is the main period when reservoir spaces are redistributed and diagenesis changes the three-dimensional spatial distribution of reservoirs.The dissolution of acid fluids and associated fillings leads to reservoir heterogeneity occurring inside the volcanic bodies.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2016年第2期278-288,共11页
Natural Gas Geoscience
基金
国家自然科学基金青年基金项目"火山岩储层中多种自生矿物共生机理及流体示踪意义"(编号:41202109)
四川省教育厅面上项目"克拉美丽气田滴西地区石炭系火山岩储层孔缝成因及分布"(编号:11ZB016)联合资助
