耐温耐盐聚合物弱凝胶体系制备及性能评价

Preparation And Performance Evaluation of Hydrophobic Monomer Polymer Weak Gel System

贺伟中 曲国辉 李博文 张子璐 田薛彬 李秀男 刘义坤

HEWeizhong QU Guohui LI Bowen ZHANG Zilu TIAN Xuebin LI Xiunan LIU Yikun

针对长期水驱后造成非均质性越发严重的高温高矿化度老油田，以华北油田为研究对象，以丙烯酰胺和丙 烯酸为主要反应单体，并引入了耐温耐盐单体NVP、疏水功能单体，通过共聚反应合成了具有疏水功能聚合物， 并与酚醛树脂交联剂发生交联反应制备了耐温耐盐弱凝胶体系，研究了弱凝胶的耐温耐盐、注入性、封堵性能及 液流转向能力。研究结果表明，当聚合物质量浓度为2000 mg/L、聚交比为1∶1.5、助剂过硫酸胺质量浓度为 2000 mg/L，在油藏温度为120 ℃、注入水矿化度为40 300.86 mg/L的条件下，所形成的弱凝胶具有良好的耐温耐 盐性能，成胶强度大于1000 mPa·s，且90 d 后的黏度平均保留率达80%以上，且90 d 后弱凝胶的微观网络骨架明 显、稳定性良好。岩心流动实验结果表明，弱凝胶体系的注入性良好，在不同渗透率级差下，弱凝胶封堵后，液流 转向效果明显，低渗层分流率增幅最高达48.33%，吸水剖面改善能力良好。通过对不同渗透率的填砂管进行封 堵，填砂管各测压点依次起压，弱凝胶运移能力良好且封堵率均达85%以上。

Aiming at the old oil fields with high temperature and high salinity，which cause more and more serious heterogeneity after long-term water flooding，Huabei oil field was taken as the research object. A hydrophobic polymer was developed by using acrylamide and acrylic acid as the main reaction monomers and introducing temperature and salt resistant monomer NVP and hydrophobic functional monomer，and a weak gel system with temperature and salt resistance was prepared through the crosslinking reaction between the polymer and the phenolic aldehyde resin crosslinking agent. The temperature and salt resistance，injectability plugging performance and fluid flow steering capacity of the weak gel system was measured. The results showed that when the concentration of polymer was 2000 mg/L，the polymerization cross ratio was 1∶1.5，the concentration of auxiliary agent amine persulfate was 2000 mg/L，the gel strength was higher than 1000 mPa·s at the reservoir temperature of 120 ℃ and the salinity of 37950.2 mg/L，moreover，the viscosity retention rate was more than 80% after aging for 90 days，which indicating that the weak gel had good temperature and salt resistance. It was observed that the micro network framework of weak gel after aging for 90 days was obvious，exhibiting good stability. The core flow test results showed that the weak gel system had good injectability. Under different permeability levels，the liquid flow diversion effect was obvious after the weak gel was blocked. The increase of the diversion rate of the low-permeability layer was as high as 48.33%，and the improvement ability of the water absorption profile was good. The sand filled pipe with different permeability was used for plugging，and the pressure measuring points of the sand filled pipe were pressurized in turn，the weak gel had good migration ability and the plugging rate was all over 85%.

10.19346/j.cnki.1000-4092.2023.03.005