渝东北田坝地区五峰—龙马溪组页岩矿物学特征及其油气地质意义

发布时间：2018-04-27 05:17

本文选题：页岩气 + 五峰—龙马溪组　；参考：《沉积学报》2017年04期

【摘要】：渝东北田坝地区五峰—龙马溪组泥页岩的矿物成分主要为石英和黏土矿物,其次为长石,此外还含有少量黄铁矿、硬石膏等含硫矿物,以及极少量的碳酸盐矿物。沉积学及矿物学研究表明,五峰—龙马溪组的沉积环境以浅海陆棚为主,而浅海陆棚属还原环境,有利于有机质富集和保存,可以更好地形成页岩气;页岩含石英量较多并且脆性指数较高,因此有利于形成裂缝以利于渗流。与相邻的涪陵地区相对比,两者可比性较高,并且渝东北田坝地区五峰—龙马溪组页岩的石英等脆性矿物含量大于涪陵地区,而黏土矿物含量、碳酸盐矿物含量远小于涪陵地区;渝东北田坝地区黏土矿物组合反映,五峰—龙马溪组已进入了晚期成岩作用阶段,该阶段所对应的有机质成熟度为高成熟—过成熟,表明其成熟度条件有利于形成页岩气藏;进一步研究还发现,五峰组及龙马溪组页岩具有较高的孔隙度和渗透性,能为页岩气储存提供较好的储集空间。
[Abstract]:The shale of Wufeng Longmaxi formation is mainly composed of quartz and clay minerals, followed by feldspar, in addition to a small amount of pyrite, anhydrite and other sulfur-bearing minerals, as well as a very small amount of carbonate minerals. Sedimentological and mineralogical studies show that the sedimentary environment of the Wufeng-Longmaxi formation is dominated by shallow-sea shelf, which is a reductive environment, which is favorable to the enrichment and preservation of organic matter and can form shale gas better. Shale has more quartz content and higher brittleness index, so it is advantageous to form fractures and facilitate percolation. Compared with the adjacent Fuling area, the content of brittle minerals such as quartz in the shale of Wufeng Longmaxi formation is higher than that in Fuling area, and the content of clay is higher in Tianba area of northeast Chongqing. The carbonate mineral content is much smaller than that in Fuling area, and the clay mineral assemblage in Tianba area of northeast Chongqing shows that the Wufeng Longmaxi formation has entered the late diagenesis stage, and the corresponding maturity of organic matter in this stage is high maturation and overmaturity. It is also found that the shale of Wufeng formation and Longmaxi formation has high porosity and permeability, which can provide a good reservoir space for shale gas storage.
【作者单位】：成都理工大学研究生院;四川中成煤田物探工程院有限公司;国土资源部沉积盆地与油气资源重点实验室成都地质矿产研究所;
【基金】：国家自然科学基金项目(41030315)~~
【分类号】：P618.13

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