川西坳陷雷口坡组气源及成藏特征

发布时间：2018-11-10 06:38

【摘要】：川西坳陷现已发现有中坝、新场、彭州等多个气藏或含气构造,展现出该地区中三叠统雷口坡组良好的油气勘探潜力。本文以石油地质学、储层地质学、构造地质学、油气地球化学和现代油气地质成藏理论等多学科理论为指导,采用野外观察采样与室内实验分析、宏观与微观相结合的方法,以大量分析化验资料和现场实际地质资料为基础,详细探讨了雷口坡组天然气来源及其相关烃源岩的地球化学特征,并在典型气藏剖析的基础上,总结天然气成藏的主要控制因素,主要得出如下结论认识:(1)雷口坡组储集层以颗粒云岩为主,储集空间类型主要为粒间和晶间溶孔,受沉积相、成岩作用、风化剥蚀及构造运动的影响,其优质储层主要分布在雷三段和雷四段。(2)目的层天然气总体表现为混源特征。其中,中坝雷三段天然气主要为下伏二叠系油型气与上覆须家河组煤型气的混源气,以二叠系油型气为主;新场及灌口 003-5井雷四段天然气与中坝雷三段天然气地化特征明显不同,本文认为为雷口坡组自身烃源岩生成的天然气;彭州1井天然气与中坝雷三段天然气特征相似,为须家河与二叠系的混源气可能存在雷口坡组自身的天然气的补充。(3)通过气源对比发现,与雷口坡组气藏成藏相关的烃源岩主要包括上三叠统须家河组、雷口坡组自身烃源岩、下伏二叠系烃源岩。其中雷口坡组自身碳酸盐岩烃源岩只在局部地区具有生烃能力,可作为气源来源的补充。须家河组与上二叠统整体上为一套优质烃源岩,是雷口坡组气藏的主要天然气来源。(4)雷口坡组成藏的主要控因素在于烃源断裂和不整合面的发育。在断裂和不整合面的沟通下,其上覆须家河组与下伏二叠系优质烃源岩所生成的油气通过断裂通道垂向或侧向运移聚集到雷口坡组优质储层中形成气藏。烃源岩的排烃高峰期、断裂的发育、圈闭的形成时期三者在时空上的有利配置是雷口坡组气藏成藏的关键。
[Abstract]:Several gas reservoirs or gas-bearing structures such as Zhongba Xinchang and Pengzhou have been found in the western Sichuan depression which shows the good oil and gas exploration potential of the Laikoupo formation of the Middle Triassic in this area. Guided by the multi-disciplinary theories of petroleum geology, reservoir geology, tectonic geology, oil and gas geochemistry and modern oil and gas geological reservoir formation theory, this paper adopts the methods of field observation, sampling and laboratory experimental analysis, and the combination of macro and micro. Based on a large amount of analytical data and field geological data, this paper discusses in detail the geochemical characteristics of the source of natural gas and related source rocks of the Leikoupo formation, and on the basis of the analysis of typical gas reservoirs, The main controlling factors of natural gas accumulation are summarized. The main conclusions are as follows: (1) the reservoir of Leikoupo formation is dominated by granular dolomite, and the reservoir space is mainly composed of intergranular and intergranular dissolved pores, sedimentary facies and diagenesis. Due to weathering and erosion and tectonic movement, the high quality reservoirs are mainly distributed in the third and fourth member of Lei. (2) the gas in the target zone is mixed source. Among them, the natural gas of the third member of Zhongba Lei is mainly the mixed source gas of the lower Permian oil type gas and the coal type gas of the Shangfu Xujiahe formation, and the Permian oil type gas is the main one. The geochemistry characteristics of Xinchang and Guankou 003-5 and Zhongba third member are obviously different, so it is considered to be the natural gas generated by the source rock of Leikoupo formation itself. The characteristics of natural gas in well Pengzhou 1 are similar to those in the third member of Zhongba Lei formation, which is a supplement to the mixed source gas between Xujiahe and Permian. (3) it is found through gas source comparison that the mixed source gas of Xujiahe and Permian may exist in the Laikoupo formation itself. The hydrocarbon source rocks related to the reservoir formation of the Leikoupo formation mainly include the Upper Triassic Xujiahe formation, the Leikupo formation own source rock, and the underlying Permian source rock. The Carbonate source rocks of Leikoupo formation have hydrocarbon generating capacity only in local areas, which can be used as a supplement of gas source. The Xujiahe formation and the Upper Permian are a set of high quality hydrocarbon source rocks, which are the main natural gas sources of the gas reservoirs of the Leikoupo formation. (4) the main controlling factors of the composition of the Laikoupo reservoir are the development of the hydrocarbon source faults and unconformities. Under the communication of fault and unconformity surface, the oil and gas generated by the Sujiahe formation and the low Permian high quality source rock migrated vertically or laterally through the fault channel to form a gas reservoir in the high quality reservoir of the Laikoupo formation. The favorable disposition of hydrocarbon expulsion peak period, fault development and trap forming period of source rock in time and space are the key to reservoir formation of Leikoupo formation.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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