四川盆地致密油气形成条件及区划

发布时间：2018-06-17 20:00

  本文选题：四川盆地 + 致密油气　； 参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：四川盆地位于扬子板块西缘,是富含天然气的大型沉积盆地。除了高产常规天然气外,四川盆地还富集非常规油气,例如煤层气、页岩气、致密砂岩油气、致密碳酸盐岩油气等。其中致密油气是本文的研究对象,通过广泛收集资料,并分析总结前人的研究成果,以川西新场地区上三叠统须家河组和川中地区下侏罗统大安寨段为例,进行致密油气的形成条件研究,并对四川盆地须家河组和大安寨段进行有利区带优选,进行致密油气勘探开发综合评价和区划。四川盆地从震旦系到侏罗系发育了多套致密油气成藏组合,粗略划分为下古生界、下二叠统、上三叠统致密气成藏组合和侏罗系致密油成藏组合,有自生自储、新生古储、古生新储三种油气成藏模式,各套成藏组合均为近源、自源充注,源储叠置或紧邻。其中,上三叠统致密气成藏组合和下侏罗统致密油成藏组合属于自生自储型,烃源岩和储层相互叠置,呈“千层饼”状,便于油气生成后直接进入储层聚集,有利于致密油气的形成。通过对烃源岩的分析,得知该区须家河组烃源岩为含煤炭质泥岩,生成煤型气,向储层内供烃;大安寨段烃源岩为大一三亚段暗色泥岩,主要生油,向上下两个亚段双向供烃。新场须家河组储层岩性以岩屑砂岩为主,孔渗性较差,为致密砂岩储层;川中地区大安寨段储层岩性以介壳灰岩为主,物性极差,在裂缝连通孔隙的作用下,成为致密碳酸盐岩储层。在研究了储层特征的基础上,探讨了储层的控制因素及源储关系,并对该盆地须家河组、大安寨段储层进行有利区带优选,圈定须家河组的5个优选区块,大安寨段4个优选区块,用容积法对大安寨段有利区块进行地质资源量计算,并选择评价指标对各区块进行综合评价及区划,将其划分为优先勘探(开发)区、次级勘探(开发)区和勘探(开发)后备区。通过综合评价与区划,得到大安寨段致密油的优先勘探区为川中区块Ⅰ,优先开发区为川中区块Ⅰ和川东区块Ⅲ,须家河组致密气的优先勘探区为川西的区块Ⅰ和区块Ⅴ,优先开发区为川西的区块Ⅰ。
[Abstract]:Sichuan Basin, located on the western margin of Yangtze plate, is a large sedimentary basin rich in natural gas. In addition to high production of conventional natural gas, the Sichuan Basin also accumulates unconventional oil and gas, such as coalbed methane, shale gas, tight sandstone oil and gas, tight carbonate oil and gas, and so on. Dense oil and gas is the research object of this paper. Through extensive collection of data and analysis and summary of previous research results, taking the Upper Triassic Xujiahe formation of Upper Triassic and the Lower Jurassic Da'anzhai formation of Central Sichuan area as examples, The forming conditions of dense oil and gas are studied, and the favorable zones are selected for the Xujiahe formation and Da'anzhai formation in Sichuan Basin, and the comprehensive evaluation and regionalization of dense oil and gas exploration and development are carried out. From Sinian to Jurassic, there are several sets of tight oil-gas accumulation assemblages in Sichuan Basin, which are roughly divided into Lower Paleozoic, Lower Permian, Upper Triassic tight Gas accumulation assemblages and Jurassic tight Oil accumulation assemblages. There are three types of new Paleozoic reservoir forming models, each set of reservoir forming assemblage is near source, self-source filling, source superposition or close proximity. Among them, the upper Triassic tight gas accumulation assemblage and the Lower Jurassic tight oil accumulation assemblage belong to the autogenetic self-reservoir type. The hydrocarbon source rocks and the reservoir superposition each other in the form of "thousand layers cake", which is convenient for oil and gas generation to enter the reservoir directly after accumulation. It is favorable to the formation of dense oil and gas. Through the analysis of the source rock, it is known that the source rock of Xujiahe formation is coal-bearing mudstone, which generates coal type gas and supplies hydrocarbon to the reservoir, and the source rock of Da'anzhai member is dark mudstone of the first and third sub-member, which mainly generates oil and supplies hydrocarbon to the upper and lower subsections in both directions. The reservoir lithology of Xinchang Xujiahe formation is dominated by lithic sandstone with poor porosity and permeability, which is a tight sandstone reservoir, and the reservoir lithology of Da'anzhai member in central Sichuan area is dominated by meso-shell limestone, and its physical property is extremely poor. A tight carbonate reservoir. Based on the study of reservoir characteristics, the controlling factors of reservoir and the relationship between source and reservoir are discussed. The favorable zones of Xujiahe formation and Da'anzhai formation in this basin are selected, and the 5 optimal selection blocks of Xujiahe formation are delineated. The volume method is used to calculate the geological resource quantity of the favorable block in Da'anzhai section, and the comprehensive evaluation and zoning of each block are carried out by selecting the evaluation index, which is divided into priority exploration (development) area. Secondary exploration (exploitation) area and exploration (exploitation) reserve area. Through comprehensive evaluation and regionalization, it is obtained that the preferential exploration area of dense oil in Da'anzhai section is block I of central Sichuan, the priority zone of development zone is block 鈪，

本文编号：2032278