用热失重法确定水合粘土水分含量及存在形式  

THE DETERMINATION OF WATER CONTENT AND BOUND WATER TYPE ON HYDRO-CLAY SURFACE BY THERMAL-WEIGHTLESSNESS

作　　者：王平全[1] 陈地奎[2] 

机构地区：[1]西南石油大学CNPC钻井液重点研究室,四川成都610500 [2]西南石油局十一普

出　　处：《西南石油学院学报》2006年第1期52-55,共4页Journal of Southwest Petroleum Institute

基　　金：中国石油天然气集团公司(CNPC)科研项目

摘　　要：以蒙脱土为例,采用热失重法定性定量确定了水合粘土中结合水类型、界限及其相对含量,并与等温吸附法结果进行了对比。结果表明,用该方法得到的水合蒙脱土中各种水分的相对含量及总含水量与等温吸附实验结果相一致。热失重(25～250℃)分析结果表明,水合蒙脱土中水分子主要存在自由水、松散吸附结合水、紧密吸附水(强吸附结合水)三种状态,分别对应于25～75℃、75～120℃、120～230℃区间里的失水。从热失重(25～250℃)规律来看,仍存在两个明显的转折点P/P_s=0.9、0.98,它们为粘土-水体系的两个特征湿度,前者为粘土表面强结合水与松散结合水(渗透结合水)之间的界限,后者为松散结合水与自由水之间的界限,验证了等温吸附法确定的两个特征湿度及对粘土表面结合水界限划分的正确性。Thermal-weightlessness is utilized to determine the type, boundary line and relative content of bound water on montmorillonite and the results of isothermal adsorption have been compared. The results show that each water relative content and total water mass on hydro-montmorillonite by the method are inconsistent to them by isothermal adsorption. Thermal weight loss analysis(25～250℃) results show that water on hydro-mont-morillonite is free water, loose bound water and strong bound water which respectively corresponding to the water loss in 25～75℃, 75～120℃, and 120～230℃. According to thermal-weightlessness regularity (25～250℃), it also has two clear turning points which are P/P_s=0.9、0. 98, the two turning points are the special humidity of clay-water system. The relative vapor pressure 0.9 is the boundary, line between the strong bound water and the loose bound water (osmotic bound water) on clays, the relative vapor pressure 0.98 is the boundary line between the loose bound water and free water on clays. The method verifies the 'two special humidity' by isothermal adsorption and the boundary line of bound water on days.

关 键 词：水合粘土 热失重法 结合水 相对含量 特征湿度 

分 类 号：TE251[石油与天然气工程—油气井工程]