影响醛冻胶成冻因素的研究

本文研究的醛冻胶是聚丙烯酰胺（PAM)被甲醛交联而形成的，研究了PAM的羟甲基化时间，pH值，甲醛和PAM的浓度，温度，矿化度，HF的浓度等因素对醛冻胶的成冻昨冻胶强度的影响，成冻时间和冻胶强度分别用转子旋转法和突破真空度法测定，研究结果表明，在本实验条件范围内，羟甲基化时间越长，pH值越低，温度越高，PAM和甲醛的逍度越大和水的矿化度越低，成冻时间的越短，醛冻胶的成冻时间与冻胶强度的关系符合一般冻胶所遵循的规律，即成冻时间越短，冻胶的强度则越高，配合冻胶在调剖堵水，酸化压裂，防砂等方面的有重要应用。

Studies on Influencing Factors for Formation of Aqueous Polyacry lamide/Formaldehyde Gel

The formation of polyacrylamide(PAM)/Formaldehyde(FA ) aqueous gel as influenced by various factors is studied through gelation time and gel strength measurementts. The PAM used is of HD=8.28% and of M=3. 31×106. The gelation time is measured by revolving magneton method and the ge l strength-by breakthrough vacuum method. It is shown that under the experimenta l conditions the gelation time decreases with increasing hydromethylation time, g elation temperature, PAM and FA concentrations, and salinity and with decreasing pH value. To this gel a general rule can be applied, too, that is: the shorter the gelation time is, the higher the gel strength is. PAM/FA aqueous gel is used in oilfield operations for water injectivity profile control and water shutoff, acidization and hydrofracturing and sand control.