大巴山前缘田坝剖面五峰组-龙马溪组页岩储层特征  

Reservoir characteristics of the Wufeng-Longmaxi Formations shale in the Tianba profile of Wuxi,Daba Mountain,China

作　　者：何佳伟 谢渊 侯明才[1] 杨平[2] 刘家洪[2] 薛时雨[1] 吴斌 王文川 HE Jiawei;XIE Yuan;HOU Mingcai;YANG Ping;LIU Jiahong;XUE Shiyu;WU Bin;WANG Wenchuan(State Key Laboratory of Oil and Gas Reset＇void＂ Geology and Eccploitation,Chengdu Uni＇,ersity of Technology,Chengdu 610059,China;Chengdu Center,China Geological Sur＇eey,Chengdu 610081,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]中国地质调查局成都中心,成都610081

出　　处：《成都理工大学学报（自然科学版）》2018年第3期356-366,共11页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中国地质调查局项目(12120114071401,121201010000150005).

摘　　要：为拓展四川盆地五峰组-龙马溪组页岩气勘探地域,以大巴山前缘巫溪县田坝剖面为基础,通过有机地球化学、矿物组分、扫描电镜、比表面积-孔径和等温吸附等方法,对五峰组-龙马溪组页岩储层的各项参数进行研究。结果显示五峰组-龙马溪组硅质泥页岩富含生物化石,按照TOC质量分数>2%为优质页岩的划分标准,仅龙马溪组发育优质页岩段,厚54.31m,TOC质量分数平均为3.80%、Rb平均为2.90%、Ro平均为2.28%;TOC与硅质、脆性矿物含量呈反比,与黏土矿物、黄铁矿含量和BJH总孔容呈正比,黏土矿物含量与BJH总孔容呈正比。有机质孔与层间页理缝构成最主要的储集空间,以两端开口的中孔为主,为页岩气的赋存提供了储集空间与渗流通道。TOC与黏土矿物含量共同控制页岩储层微观孔隙结构的发育。储层孔隙度与渗透率稳定,比表面较大,吸附量大,吸附能力强。与焦页1井对比分析,发现巫溪田坝地区龙马溪组页岩具有高TOC、高Rb、高硅质含量、高白云石含量和低长石、低碳酸盐岩、低孔隙度、低渗透率的"四高四低"特征,热演化程度适中,微孔隙-裂缝系统发育,有利于页岩气富集。The methods of organic geochemistry, mineral composition, scanning electron microscopy, specific surface area aperture, and isothermal adsorption are used to study the parameters of the Wufeng Longmaxi Formation shale reservoir in the Tianba section of Wuxi area so as to expand the shale gas exploration area of the Wufeng Longmaxi Formation in the Sichuan Basin. The results show that siliceous shale from the Wufeng Longmaxi Formation is rich in fossils and that the Longmaxi Formation possess a high quality shale segment according to the standard for quality shale of TOC（mass fraction of the total organic carbon）2%. The thickness of high quality shale segment in Longmaxi Formation is 54.31 m with an average TOC of 3.80%, Rb of 2. 90%, and Ro of 2. 28%. TOC is inversely proportional to siliceous and brittle mineral contents, is proportional to clay mineral, pyrite content, and total pore volume of BJH. Organic pores and interracial linings are the most important reservoir space in the study area and the mesopores, open gaps at both ends, provide the reservoir space and seepage channel for the occurrence of shale gas. Both TOC and clay mineral content control the development of microscopic pore structures in shale reservoirs. Wufeng Longmaxi Formation shale reservoir has stable reservoir porosity and permeability, large adsorption capacity, strong adsorption capacity. Compared Wuxi Tianba area with Well Jiaoye 1, it is found that the Longmaxi Formation shale in the Wuxi Tianba area has high TOC, Rb, siliceous, and dolomite content, low feldspar, carbonate, low porosity and permeability.- “four highs and four lows” characteristics. Generally, the Wufeng Longmaxi Formation has moderate thermal evolution extent, better microporosity and microfracture system, which are favorable for shale gas enrichment.

关 键 词：页岩 储昙 五峰组龙马浸组 巫浸 焦页1井 

分 类 号：P618.13[天文地球—矿床学]