耐温耐盐酚醛冻胶研制及性能调控机理

注水油藏控水稳油过程中最常用的堵剂之一是聚合物冻胶,而存在高温高盐苛刻条件的油藏中冻胶应用的关键是其耐温抗盐性能。因此分别评价了在盐含量为25×10⁴mg/L的模拟盐水中,110℃和155℃条件下不同分子结构的丙烯酰胺(AM)/2-丙烯酰胺-2-甲基丙磺酸(AMPS)二元共聚物和AM/AMPS/N-乙烯基吡咯烷酮(NVP)三元共聚物与对苯二酚、六亚甲基四胺交联制备的冻胶成胶性能,明确了以AMPS含量为30%的AM/AMPS共聚物做主剂更容易形成稳定冻胶。通过分析不同脱水程度冻胶的固体核磁共振碳谱(C-NMR)谱图发现,耐温耐盐冻胶的重要特征是长期热处理后仍保持一定含量的酰胺基甲基丙磺酸。在此基础上综合冻胶的冷冻扫描电镜(Cryo-SEM)和红外光谱(FTIR)分析结果认为,选择高AMPS含量的聚合物,调控交联剂的用量,可以优化冻胶中伯酰胺、酰胺基甲基丙磺酸等盐敏基团的存在状态,由此有效抑制酰胺基甲基丙磺酸的内催化水解,从而调控冻胶的耐温耐盐性能。

Development of temperature and salinity resistant phenolic gel and its performance regulation mechanism

As a plugging agent,polymer gel is one of the most commonly used in the process of conformance control in water-flooding reservoirs,and the key to the application of gel in reservoirs in the harsh conditions of high temperature and high salinity is its temperature and salinity-resistance performance.Therefore,this paper evaluates the forming performance of gels prepared by cross-linking acrylamide (AM)/2-acrylamide-2-methylpropanesulfonic acid (AMPS) coplymers and AM/AMPS/N-vinylpyrrolidone (NVP) terpolymer with hydroquinone and hexamethylenetetramine in simulated brine with a salinity of 25×10⁴mg/L at 110℃ and 155℃,respectively.It is clear that AM/AMPS copolymer with 30% AMPS content as the main agent is more likely to form a stable gel.The analysis of solid-state nuclear magnetic resonance carbon (C-NMR) spectroscopy of gels with different degrees of dehydration reveals that the temperature and salinity-resistant gels are mainly characterized by the retention of a certain amount of amido methylpropanesulfonic acid after long-term heat treatment.On this basis,the results of cryo-SEM and FTIR analysis indicate that the selection of polymers with high AMPS content and the regulation of the amount of cross-linking agent can optimize the salinity-sensitive groups such as primary amide and amido methylpropanesulfonic acid in the gel,thus effectively inhibiting the intramolecular catalytic hydrolysis of amido methylpropanesulfonic acid and regulating the temperature and salinity resistance of the gel.