周期性注入弱凝胶技术研究与应用

Research and Application of Periodic Injection of Weak Gel Technology

弱凝胶调驱是改善和提高注水波及效率的主要手段,但由于弱凝胶的强度较低,导致其有效期较短。为此,提出了周期性注入弱凝胶技术。采用岩心平面模型进行了非周期性注入弱凝胶调驱试验和周期性注入弱凝胶调驱试验,结果表明:非周期性注入弱凝胶调驱可以封堵高渗透层,提高注入压力,降低综合含水率,提高采收率;周期性注入弱凝胶调驱可以进一步改善弱凝胶的调驱效果,延长弱凝胶调驱的有效期,从而使采收率得到进一步提高。赵108断块采用周期性注入弱凝胶技术进行了两期调驱,注入弱凝胶期间和注入以后,注入压力上升,吸水剖面得到调整,油井含水下降,产油量上升。一期调驱有效期1.0a,二期调驱有效期1.5a,两期调驱共增油20500t。

Weak gel profile control is the main way to improve and enhance water flood sweep efficiency,but the low strength of weak gel will cause short period of validity. Therefore, periodic injection of weak gel was put forward. Using core plane model, the experiments of periodic and nonperiodic weak gel injection were conducted. The results showed that nonperiodic weak gel injection can block the high permeability zone,increase the injection pressure, lower the water cut,and enhance the recovery. Periodic injection can improve the profile control results, prolong the period of weak gel validity, and enhance the recovery further. Periodic injection was used in Fault Block Zhao 108, the injection pressure increased during and after gel injection. The intake water profile was adjusted. Field water cut reduced and oil production rate increased. The primary profile control was effective for one year; the secondary profile control lasted for one and half year. The incremental oil production was 20 500 tons.