成岩早期大气淡水淋滤作用对碳酸盐岩储集层的影响——以塔里木盆地顺南地区为例  

Effect of Atmospheric Freshwater Leaching on Carbonate Reservoirs during the Early Diagenetic Stage—A Case Study of Carbonates in the Shunnan Area,Tarim Basin

作　　者：杨磊磊 陈冬华 于林姣 刘建良 YANG Lei-lei;CHEN Dong-hua;YU Lin-jiao;LIU Jian-liang(The Unconventional Petroleum Research Institute,China University of Petroleum(Beijing),Beijing 102249,China;School of Geosciences,China University of Petroleum(East China),Qingdao Shandong 266580,China)

机构地区：[1]中国石油大学(北京)非常规油气科学技术研究院,北京102249 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《矿物岩石地球化学通报》2020年第4期843-852,870,共11页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(41702249);中国科学院战略先导科技专项(XDA14010401)。

摘　　要：在碳酸盐岩储集层中,由大气淡水淋滤作用形成的岩溶孔洞是重要的油气储集空间,但大气淡水淋滤对碳酸盐岩储集层的改造机制尚不明确,因而制约了对碳酸盐岩储集层的评价和勘探。本文以塔里木盆地顺南地区4种典型的碳酸盐岩储集层为研究对象,以理论分析和数值模拟为手段,对不同条件下大气淡水淋滤作用造成的储集层的矿物溶蚀、沉淀、转化以及孔隙度变化进行了定量研究。结果表明,在近地表低温低压条件下,大气淡水对碳酸盐岩的淋滤作用主要表现为方解石的溶蚀,随流体向深部运移,以及方解石的沉淀或白云石化。大气淡水淋滤对储集层的影响深度和程度与淋滤速度、时间等因素均有关,另外,在矿物种类不同的碳酸盐岩储集层中,矿物的溶解、沉淀和转化关系差异较大。Karst pores formed by the atmospheric freshwater leaching are important oil-gas storage spaces in carbonate reservoirs.However,the reformation mechanism of carbonate reservoirs by the atmospheric freshwater leaching is unclear.This has restricted the carbonate reservoir evaluation and oil-gas exploration.In this study,4 kinds of typical Ordovician carbonate reservoirs in the Shunnan area,Tarim basin have been chosen as the research objects for quantitatively studying the mineral dissolution,precipitation,transformation,and porosity changes of reservoirs caused by the atmospheric freshwater leaching under various conditions using the combined method of theoretical analysis and numerical simulation.Results show that the freshwater leaching effect on carbonate rocks is mainly manifested by the calcite dissolution at near the surface under conditions of low temperature and low pressure,while,it is mainly manifested by the calcite precipitation or dolomitization in depth.The influencing depth and extent of the atmospheric freshwater leaching on carbonate reservoirs are related to the leaching speed,leaching duration,and so on.In carbonate reservoirs with different mineral components,the dissolution,precipitation,and transformation relations of minerals are of great differences.

关 键 词：碳酸盐岩储集层 大气淡水淋滤 矿物转化 孔隙度 塔里木盆地 

分 类 号：P618.130.21[天文地球—矿床学]