不同淡水成岩体系下长石溶蚀的对比实验  

Contrast Experiment about Dissolution of Feldspar in Different Freshwater Diagenetic Systems

作　　者：徐梅桂[1,2] 张哨楠[1,3] 伏美燕[1,2] 范筱聪[1,2] 万友利[1,2] 白晓亮[1,3] 

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,四川成都610059 [2]成都理工大学能源学院,四川成都610059 [3]西南石油大学资源与环境学院,四川成都610500

出　　处：《现代地质》2013年第4期925-933,共9页Geoscience

基　　金：国家自然科学基金项目(40972098)

摘　　要：在相同温度、压力(25℃,101325kPa)条件下,通过对不同淡水成岩体系下长石溶蚀的对比实验来探讨大气水-砂岩的相互作用,实验证实了大气水对铝硅酸盐矿物确实存在淋滤作用,可以形成次生溶孔。该实验分别模拟了含泥开放体系、无泥开放体系和无泥封闭体系等3种不同成岩体系下的天然淡水对长石的溶蚀。反应后检测溶液中的Al3+,Si4+,Ca2+,K+,HCO3-等离子浓度的变化及不同体系下的钾长石和石英颗粒的扫描电镜(SEM)观察结果表明:长石在3种体系内均有不同程度的溶蚀,并且溶蚀的程度表现为,含泥开放体系>无泥开放体系>无泥封闭体系。无泥开放体系和无泥封闭体系下长石发生溶蚀的同时,也观察到石英的微溶蚀。在这3种成岩体系下,长石溶蚀程度与有机质含量、pH值有相关性,在开放体系中长石溶蚀较封闭体系更加明显。In the same conditions of temperature and pressure（25 ℃ ,101,325 kPa）,the interaction of atmospheric water-sandstone by comparative experiment of feldspar dissolution under different systems is explored in this paper,and it is confirmed that atmospheric water can eluviate aluminosilicate minerals. Feldspar dissolution by natural fresh water is simulated by comparative experiments among open system with sludge,open system without sludge and closed system without sludge. After the reaction,the change in the concentrations of Al3 ＋ , Si4 ＋ ,Ca2 ＋ ,K ＋ and HCO 3ions in solution and scanning electron microscopy （SEM） observation showed that feldspar in the three systems have different levels of dissolution. Dissolution of different degree is open system with sludge ＆gt; open system without sludge ＆gt; closed system without sludge. Not only feldspar dissolution but also the quartz micro-dissolution phenomena are observed in open system without sludge and closed system without sludge. Degree of feldspar dissolution has relation with organic matter content and pH value. The phenomenon of feldspar dissolution in open system is more obvious than in the closed system.

关 键 词：长石 溶蚀 扫描电镜 次生孔隙 

分 类 号：TE122.2[石油与天然气工程—油气勘探]