摘要
为明确海相与海陆过渡相页岩孔隙特征之间的差异性,以上扬子黔西北地区为例,对区内广泛分布的海相龙马溪组、牛蹄塘组及海陆过渡相龙潭组页岩孔隙特征进行研究,分析页岩内部孔隙的类型、发育与分布模式,进一步探索其差异性成因。研究表明:海相页岩整体是以有机孔为主、石英与碳酸盐类矿物等刚性颗粒间孔为辅的孔隙分布模式,有机孔相对含量约占总孔隙的50%以上;海陆过渡相页岩孔隙的孔径较海相页岩大且变化范围大,为无机粒间/粒内孔与微裂缝占主体、有机孔次之的孔隙分布模式,其内部碳酸盐类矿物溶蚀孔/缝大量发育,有机孔相对含量仅占总孔隙的20%左右;形成时期沉积环境的差异是海相与海陆过渡相页岩孔隙发育存在差异的最主要原因,后期保存条件不同也会产生一定程度影响。针对储层孔隙特征进行差异性分析对页岩气资源勘探开发有重要的指导意义。
In order to clarify the differences between the pore characteristics of marine and paralic transitional shale,in the case study of Upper Yangtze Region,Northwest Guizhou,the pore characteristics of Longmaxi Formation marine shale,Niutitang Formation shale and Longtan Formation paralic transitional shale widely distributed in the area were studied,and the types and development and distribution patterns of pores inside the shale were analyzed to further explore the causes of difference.The study showed that,the overall pore distribution pattern of marine shale was dominated by organic pores and followed by rigid intergranular pores such as quartz and carbonate minerals,with the relative content of organic pores accounting for more than 50%of the total pores;the diameter of pores in marine-continental transitional shale was greater and more variable than that of marine shale,and the pore distribution pattern was dominated by inorganic intergranular/intragranular pores and microfractures,followed by organic pores,with a large number of dissolved pores/fractures developed in carbonate minerals,and the relative content of organic pores only accounting for about 20%of the total pores.The difference of sedimentary conditions in formation period was the root cause for the difference of pore development between marine and marine-continental transitional shale,and the different preservation conditions in the later stage also had a certain influence.Differential analysis of reservoir pore characteristics provides an important guidance to the exploration and development of shale gas resources.
作者
史淼
张金川
袁野
陶隆凤
刘钊
Shi Miao;Zhang Jinchuan;Yuan Ye;Tao Longfeng;Liu Zhao(Hebei GEO University,Shijiazhuang,Hebei 050031,China;Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,Wuhan,Hubei 430074,China;China University of Geosciences(Beijing),Beijing 100083,China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2022年第3期9-17,共9页
Special Oil & Gas Reservoirs
基金
国家自然科学基金“贵州岑巩区块牛蹄塘组页岩黄铁矿成因机制及其成岩环境意义”(42002156)
河北省自然科学基金“冀北下马岭组地层黄铁矿特征及页岩气指示意义”(D2021403015)
构造与油气资源教育部重点实验室开放研究基金“下古生界海相页岩黄铁矿成因机制及其页岩气指示意义”(TPR-2021-07)
河北省高等学校科学技术研究项目“河北张家口下马岭组海相页岩孔隙形成与演化特征”(QN2021027)。
关键词
海相页岩
海陆过渡相页岩
孔隙特征
差异分析
黔西北
marine shale
marine-continental transitional shale
pore characteristics
difference analysis
northwestern Guizhou