摘要
聚合物驱后的油层非均质性更加严重，低效、无效循环严重。常规凝胶调剖剂在地层条件下经剪切后黏弹性大幅下降，严重影响了调剖效果。本文通过考察pH值、阴离子型聚丙烯酰胺CH601浓度、交联剂SQ-1浓度、稳定剂TYB-5浓度对自修复凝胶体系成胶性能的影响，进而得到最佳配方。考察了最佳配方自修复凝胶体系的耐温性、抗剪切性及封堵性能。结果表明：最佳自修复凝胶体系配方为：3000~5000 mg/L聚合物，3000 ~4500 mg/L交联剂，200~400 mg/L稳定剂。体系的pH值在5~6之间。该体系的热稳定性良好，在45℃下放置300 d后的黏度保持率为76.9%，弹性模量保持率为76.5%。该自修复凝胶体系具有较强的抗剪切性能，在45℃条件下初次成胶后经高速混调器剪切后，再次放入45℃烘箱内，成胶后再用相同的方式剪切，如此反复6次仍能成胶，成胶黏度为4430 mPa?s，黏度恢复率达到45%以上。岩心实验结果表明自修复凝胶体系对水测渗透率为1.2~4.5μm2的人造石英砂岩心的封堵率均在99%以上，残余阻力系数为68~147。
Abstract
Reservoir heterogeneity and invalid water cycle is more serious after polymer flooding. Viscoelastic behavior of traditional gel profile control agent is decreased sharply after being sheared in reservoir, which reduced the effect of profile control obviously. In the paper, the effect of anionic polyacrylamide CH601 concentration, crosslinker SQ-1 concentration, stabilizer TRB-5 concentration and the value pH on the gelling performance of the self-repairing gel system (SRGS) were investigated, as a result, the optimum formula was obtained. Moreover, the temperature tolerance, shearing, sealing characteristics of self-repairing gel system were investigated. The results showed that the optimum formula of the SRGS was as follows, 3000-5000 mg/L anionic polyacrylamide CH601+ 3000-4500 mg/L crosslinker SQ-1+200-400 mg/L stabilizer TRB-5, at the value pH 5-6. Heat stability of self-repairing gel system was good. At the temperature of 45℃,viscosity and elasticity modulus retention rate was 76.9% and 76.5%, respectively. At the temperature of 45℃, after the system went through the gelling-shearing-gelling- shearing process for three times, the gel viscosity was above 4000 mPa?s, and the viscosity recovery rate was above 45%. Core test demonstrated that the plugging rate of the SRGS was above 99% for silica sand artificial core with water permeability of 1.2-4.5 μm2, and residual resistance factor was 68-147.
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