中扬子地台宜昌地区寒武系水井沱组优质页岩储层发育特征及天然气富集机理研究  

Reservoir characteristics and natural gas accumulation of shales within the Cambrian Shuijingtuo Formation in the Yichang region,middle Yangtze Platform

作　　者：蔡宁波 王琳霖 鲍一遥 李怡普 万泽鑫 康志梅 罗胜元[5] CAI Ningbo;WANG Linlin;BAO Yiyao;LI Yipu;WAN Zexin;KANG Zhimei;LUO Shengyuan(Institute of Advanced Studies,China University of Geosciences,Hubei 430070,Wuhan,China;New Geological Energy Exploration and Development Engineering,Technology Research Center of Hunan,Changsha 410014,Hunan,China;Petroleum Exploration&Production Research Institute,SINOPEC,Beijing 100083,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan 430100,Hubei,China;Wuhan Center of China Geological Survey,Wuhan 430205,Hubei,China)

机构地区：[1]中国地质大学(武汉)高等研究院,湖北武汉430070 [2]湖南省地质新能源勘探开发工程技术研究中心,湖南长沙410014 [3]中国石化石油勘探开发研究院,北京100083 [4]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [5]中国地质调查局武汉地质调查中心,湖北武汉430205

出　　处：《中国地质》2025年第1期111-130,共20页Geology in China

基　　金：国家自然科学基金项目(41702135);“十四五”前瞻性基础性重大科技项目“准噶尔盆地不整合地层油气成藏研究”(2021DJ0405)联合资助。

摘　　要：【研究目的】湖北省宜昌地区是中扬子地台页岩气勘探的重要前沿领域之一,近年来的野外调查与钻探工作表明该地区的寒武系水井沱组是极具潜在工业价值的页岩气勘探靶区。【研究方法】本文针对该地区最新的钻孔资料,利用多学科交叉手段,查明该地区水井沱组优质页岩储层的特征以及油气富集规律。【研究结果】水井沱组页岩有机质丰度高,有机碳含量(TOC)主要分布在0.56%~8.42%,干酪根以II1型和I型为主,Ro等效值分布在2.4%~3.2%。水井沱组页岩储层孔隙度主要分布在0.5%~9.1%,渗透率主要分布在0.019×10^(-3)~0.540×10^(-3)μm^(2)。水井沱组页岩的储集空间主要包括有机孔隙、无机孔隙以及裂缝等类型。储集空间的发育程度主要与有机质富集程度、黏土矿物含量以及页理缝的发育程度有关。天然气主要以吸附气(45.21%~81.44%)和游离气(18.56%~54.79%)的状态赋存于水井沱组页岩储层中,溶解气的比例相对较小。水井沱组页岩储层的含气性主要受有机碳含量、脆性矿物比例以及裂缝发育程度有关。有机碳比例、脆性矿物比例和裂缝发育程度越高,储层含气性越好。【结论】综合地球化学、岩石物理和现场实测数据,认为宜昌地区水井沱组页岩气极具商业价值,是中国南方理想的页岩气勘探开发目标之一。[Objective]The Yichang area of Hubei Province is one of the important frontier areas of shale gas exploration on the middle Yangtze platform.Field investigation and drilling works in recent years show that the Cambrian Shuijngtuo Formation in this area is a shale gas exploration target with great potential industrial value.[Methods]Based on the latest borehole data in this area,the characteristics of high-quality shale reservoirs and the hydrocarbon accumulation patterns are identified by means of multidisciplinary methods.[Results]The shale of the Shuijngtuo Formation has high organic matter abundance,with TOC mainly distributed in the range of 0.56%-8.42%.Organic matter is dominated by type II1 and type I kerogen,and Ro equivalent value is distributed in the range of 2.4%-3.2%.Porosity and permeability values of shale reservoirs within the Shuijngtuo formation are mainly in the range of 0.5%-9.1%and 0.019×10^(-3)-0.540×10^(-3)μm^(2).Reservoir pore spaces of shales within the Shuijngtuo Formation mainly includes organic pores,inorganic pores and fractures.Occurrence of pore spaces is mainly related to the enrichment degree of organic matter,the content of clay minerals and the development degree of fractures.Natural gas is mainly attached to the shale reservoir in the form of adsorbed gas(45.21%-81.44%)and free gas(18.56%-54.79%),and the proportion of dissolved gas is relatively small.The gas bearing property of the shale reservoir is mainly related to the content of organic carbon,the proportion of brittle minerals and the degree of fracture development.The higher the proportion of organic carbon,the proportion of brittle minerals,and the degree of fracture development,the better the gas bearing property of the reservoir becomes.[Conclusions]Based on the geochemical,petrophysical and field measurement data,the shale gas of the Shuijingtuo Formation in Yichang area has great commercial value and is one of the ideal targets for shale gas exploration and development in southern China.

关 键 词：页岩储层 页岩油气 控制因素 中扬子地台 成藏机理 油气勘查工程 

分 类 号：P618.13[天文地球—矿床学]