高温、高盐环境双重交联凝胶调堵体系的制备及性能

Double Cross-linked Gel Plugging Agent Used in High-temperature and High-Salinity reservoirs

杨祖国 郭继香 马清杰 郭锦棠 高秋英

YANG Zuguo GUO Jixiang MA Qingjie GUO Jintang GAO Qiuying

针对现有油田调堵剂高温地层条件下凝胶时间较短、不耐稀释、长期稳定性差的问题，采用二级交联结构设计，以甲基丙烯酸缩水甘油酯（GMA）、二乙二醇二甲基丙烯酸酯（EDMA）为共聚单体，氧化氢叔丁醇（TBHP）为引发体系，聚乙二醇（PEG）为有机溶剂，气相二氧化硅（AEROSIL）为增强剂，合成耐温耐盐性双重交联凝胶体系，研究了各组分加量对凝胶成胶时间及储能模量的影响，考察了凝胶的黏弹性、老化稳定性、耐地层水稀释性和封堵性。研究结果表明，凝胶体系的最优配方为：10% GMA+0.7% EDMA+0.066% TBHP+3% AEROSIL（其余为 PEG 溶剂）。该凝胶体系的初始黏度为 315 mPa·s，凝胶时间为 2～10 h，储能模量为 5230 Pa，抗压强度为0.221 MPa。所生成的凝胶在矿化度为2.2×105 mg/L 的模拟地层水中 140 ℃高温老化 30 d，无体积收缩，储能模量可达 4000 Pa 以上。该凝胶具有较好的耐地层水稀释能力，加入体积分数为40%的地层水时所形成凝胶的剪切强度虽降低约18%，但储能模量仍可达4000 Pa以上。凝胶基液表现出良好的注入稳定性，驱替实验反向突破压力梯度达5.5 MPa/m，所形成凝胶的力学强度可满足封堵裂缝通道需求，为高温高矿化度油藏提供了一种有潜力的堵调材料。

The existing gel has the problems of short gel time，poor dilution resistance and poor long-term stability under high temperature formation conditions. Based on a two-level cross-linked structure design，a temperature and salt-resistant double cross-linked gel profile control and plugging agent was synthesized using glycidyl methacrylate（GMA）and diethylene glycol dimethacrylate（EDMA）as copolymer monomers，tert-butyl hydroperoxide（TBHP）as the initiation system，polyethylene glycol （PEG）as organic solvent，and fumed silica（AEROSIL）as the reinforcing agent. The effects of each component dosage on the gelling time and storage modulus of the gel were studied. The performance of viscoelasticity，aging stability，dilution resistance to formation water and plugging property of the gel were investigated. The results showed that the optimal formula of gel system was 10% GMA+ 0.7% EDMA+ 0.066% TBHP+3% AEROSIL，and the rest was PEG solvent. The initial viscosity of the system was 315 mPa·s，the gelling time was 2—10 hours，the storage modulus was 5230 Pa，and the compressive strength was 0.221 MPa. After aging for 30 days at the temperature of 140 ℃ in the simulated formation water with a salinity of 2.2×105 mg/L，there was no volume shrinkage，and the storage modulus could reach more than 4000 Pa. The gel had good dilution resistance to formation water. When adding formation water with volume fraction of 40%，the shear strength of the gel was reduced by about 18%，but the storage modulus could still reach more than 4000 Pa. The gel base fluid showed good injection stability，and the reverse breakthrough pressure gradient in the displacement experiment reached 5.5 MPa/m，the mechanical strength of the formed gel could meet the needs of plugging fracture channels. A potential plugging and regulating material for high-temperature and high-salinity reservoirs was provided.

10.19346/j.cnki.1000-4092.2025.01.012