用于海外河油田调驱的有机铬交联聚合物弱凝胶体系及性能评价

Performance Evaluation of Organic Chrome Cross-linked Polymer Weak Gel for Profile Control in Haiwaihe Oilfield

为降低海外河油田油井含水率,改善水驱开发效果,针对油藏条件用部分水解聚丙烯酰胺(HPAM)和有机铬交联剂配制了有机铬交联聚合物弱凝胶,研究了弱凝胶的耐温、耐盐、抗剪切性、注入性、封堵性及吸水剖面改善能力。研究结果表明,在油藏温度70℃下,配方为2000 mg/L HPAM+100 mg/L有机铬交联剂弱凝胶调驱体系的成胶时间为3 d,成胶强度为C级。弱凝胶具有较好的耐温性、抗盐性及抗剪切性,耐温可达90℃,抗盐可达3621.2 mg/L。岩心流动实验结果表明,弱凝胶体系的注入性和封堵性良好,可提高采收率10.4%数12.7%;吸水剖面改善能力较好,对非均质性岩心的吸水剖面改善率大于90%。

In order to reduce the water content of oil well and improve the development effect of water flooding in Haiwaihe oilfield, chromium organic cross-linked polymer weak gel was prepared by partially hydrolyzed polyacrylamide （HPAM） and organic chrome crosslinking agent based on reservoir condition. The temperature resistance, salt tolerance, shearing resistance, injectivity, plugging property and injection profile improvement ability of weak gel were studied. The results showed that the gelling time was three days and the gel strength was C grade when the temperature was 70℃ and the formula of weak gel flooding system was 2000 mg/L HPAM＋ 100 mg/L organic chrome crosslinking agent. The weak gel had good temperature resistance, salt tolerance and shearing resistance, the temperature-resistance capacity was up to 90 ℃, and salt resisting concentration was 3621.2 mg/L. Core flow experiment results showed that the weak gel had good injectivity, plugging property and injection profile improvement ability with 10.4%--12.7% enhanced oil recovery rate and above 90% profile improvement rate to heterogeneous cores.