不同赋存环境下碳酸盐岩溶蚀过程试验模拟研究  

Experimental simulation of the carbonate dissolution process under different occurrence conditions

作　　者：林云[1,2] 任华鑫 武亚遵 贾方建[1] 刘朋 梁家乐 LIN Yun;REN Huaxin;WU Yazun;JIA Fangjian;LIU Peng;LIANG Jiale(Institute of Resources&Environment,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region,Jiaozuo,Henan 454000,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454003 [2]中原经济区煤层(页岩)气河南省协同创新中心,河南焦作454000

出　　处：《水文地质工程地质》2021年第2期15-26,共12页Hydrogeology & Engineering Geology

基　　金：国家自然基金资助项目(41602265,41502224);河南省博士后基金项目(16A170012);河南省高等学校青年骨干教师培养计划(2019GGJS055)。

摘　　要：目前,有关碳酸盐岩溶蚀过程的研究多集中在单一环境平衡状态下,不同赋存环境、微观尺度上的研究较少。鉴于此,为探讨不同赋存环境下碳酸盐岩溶蚀过程及微观变化特征,借助研制的岩溶水系统不同赋存环境下水岩相互作用模拟装置,选取典型岩溶水系统开放环境、半封闭环境与封闭环境的岩样,以CO_(2)溶液为酸性流体介质,开展室内溶蚀模拟试验,研究岩溶水中特征组分的变化规律进行模拟实验,并从宏观和微观尺度,研究岩溶水系统不同赋存环境下的碳酸盐岩溶蚀变化特征。结果显示:不同赋存环境下Ca^(2+)、HCO3^(-)含量、饱和指数及pH值空间变化特征不同,各特征组分均呈现出随径流方向、溶蚀时间逐渐增大的趋势。不同赋存环境下,碳酸盐岩受水溶液中CO_(2)含量的影响,在补给区的开放环境下溶蚀性最强,形成连通性较高的溶孔、溶隙。碳酸盐岩总溶蚀率均值是半开放环境的1.43倍,是封闭环境的2.70倍,半封闭与封闭环境下碳酸盐岩溶蚀后的微观结构介于孤立微孔与完全连通性溶隙之间。此外随深度的变化溶蚀量呈逐渐减弱的趋势,且浅部的变化更为明显。碳酸盐岩的溶蚀作用还受岩性控制,其随岩石中CaO/MgO比值的增大而增强。At present, the researches on the dissolution process of carbonate rocks are mostly concentrated on a single environmental equilibrium state, and the researches in different occurrence environments and at a micro scale are relatively weak. In order to explore the dissolution process and the micro change characteristics of carbonate rocks in different occurrence environments, with the help of the developed simulation device of waterrock interaction in different occurrence environments of karst groundwater systems, the indoor dissolution simulation test of the representative rock samples of karst groundwater systems is carried out in the typical open environment, semi-closed environment and closed environment. CO2 solution is used as the acid fluid medium.The changes and control factors of characteristic components in karst groundwater are examined, and the characteristics of the dissolution of representative minerals in different occurrence environments of karst groundwater systems are explored from the macro and micro perspectives. The results show that the spatial variation characteristics of the contents of Ca2+ and HCO3-, saturation index and pH value are different in different occurrence environments, and each characteristic component presents an increasing trend with the runoff direction and dissolution time. Under the influence of the CO2 in the aqueous solution, the carbonate rock has the strongest dissolution in the open environment of the supply area, forming the solution pores and openings with high connectivity. The average value of the total dissolution rate of the carbonate rock is 1.43 times that of the total dissolution rate in the semi-open environment, 2.70 times that of the total dissolution rate in the closed environment. The microstructure in the semi closed environment is between the two forms of the isolated micropores and the completely connected gaps. In addition, with the change of depth, the amount of dissolution decreases gradually, and the change of shallow part is more obvious. The di

关 键 词：赋存环境 碳酸盐岩 溶蚀特征 微观结构 

分 类 号：P642.25[天文地球—工程地质学]