高温高盐条件下调剖用酚醛冻胶的研制

Development of Phenolic Gel for Profile Control under High Temperature and High Salt Condition

针对温度110℃和130℃、水中盐含量41529 mg/L的条件,实验收集了HPAM、AM-AMPS两类聚合物,考察了这些聚合物与对苯二酚、乌洛托品的交联规律。研究结果表明,当w(交联剂)≥0.3%时3种聚合物G3515、QC-13、QC-6构建的成胶液在各组分质量分数相同的情况下成胶时间相近,但当w(交联剂)≤0.2%时以分子中AMPS含量较高的AM-AMPS共聚物QC-6构建的成胶液成胶时间最长、以部分水解聚丙烯酰胺G3515构建的成胶液成胶时间最短。从冻胶稳定性看,QC-6聚合物冻胶稳定区域最大,G3515冻胶稳定性区域最小。综合冻胶成胶时间、冻胶强度和冻胶稳定性,建议以一定用量QC-6聚合物和低用量交联剂构建适应110℃深部封堵段塞,以高用量G3515聚合物和高用量交联剂构建适应110℃近井封堵段塞。通过XPS、Cryo-SEM、C-NMR对冻胶分析表明,冻胶在高温中高盐条件下脱水收缩现象主要归因于聚合物中伯酰胺、AMPS链节的水解以及所生成的羧酸根与钙镁离子的螯合作用造成交联聚合物亲水性不断降低、交联密度不断提高。

Under the conditions of 110℃and 130℃and 41529 mg/L salt content in water,HPAM and AM-AMPS polymers were collected,and the crosslinking laws of these polymers with hydroquinone and hexamethylene-tetramine were investigated.The results show that when w(crosslinking agent)≥0.3%,the gelling time of the gelling solutions constructed by the three polymers G3515,QC-13 and QC-6 is similar under the same mass fraction of each component,but when w(crosslinking agent)≤0.2%,the gelling time of the gelling solutions constructed by QC-6 is the longest,and the gelling time of the gelling solution constructed by partially hydrolyzed polyacrylamide G3515 is the shortest.In terms of gel stability,the stability zone of QC-6 polymer gel is the largest and that of G3515 gel is the smallest.Based on the gel forming time,gel strength and gel stability,it is recommended for a deep plugging slug suitable for 110℃to be built using a certain amount of QC-6 polymer and low amount of crosslinking agent,and a near-well plugging slug suitable for 110℃using a high amount of G3515 polymer and high amount of crosslinking agent.The analysis of gel by XPS,Cryo SEM and C-NMR shows that the dehydration shrinkage of gel under the condition of high temperature,medium-high salinity is mainly due to the hydrolysis of primary amide and AMPS chain links in the polymer and the chelation between carboxylic acid radical and calcium and magnesium ions,resulting in the continuous decrease of hydrophilicity and increase of crosslinking density of crosslinked polymer.