砂岩油藏聚窜通道深部长效封窜技术研究与应用

Research and Application of Long-term Plugging Technology for Deep Polymer Channeling in Sandstone Reservoir

针对疏松砂岩油藏注聚区块注聚窜聚严重、封堵技术有效率低、有效期短的问题,研究了一种无机矿聚物溶胶深部封窜剂,用于封堵注聚井聚窜通道,并提出了无机矿聚物溶胶深部封窜剂+多粒径复合纤维防漏失堵剂封口的长效封窜工艺。室内研究表明,无机矿聚物溶胶深部封窜剂的岩心突破压力大于3.6 MPa,水驱2PV后压力未见明显变化,多粒径复合纤维防漏失堵剂的抗压强度大于20 MPa,漏失量与水泥类堵剂相比下降40%以上。现场试验表明聚窜通道深部长效封窜技术可有效改善砂岩油藏注聚井聚驱效果,提高注聚受益油井产量,封窜平均有效期达到1年以上。

The channeling in polymer injection block of unconsolidated sandstone reservoir is serious,and the current plugging technol⁃ogies are of low efficiency and short validity period.Therefore,a kind of deep plugging agent of inorganic mineral polymer sol is stud⁃ied,which is used to plug the channeling channel of polymer injection wells.And a long-term plugging technology is proposed for plug⁃ging the channeling channel with the inorganic mineral polymer sol and sealing with multi-particle-size composite fiber.Laboratory re⁃search shows that:the core breakthrough pressure of the inorganic polymer sol deep channeling plugging agent is more than 3.6 MPa,and the pressure has no obvious change after 2 PV water flooding;the compressive strength of the multi-particle-size composite fiber leakage prevention plugging agent is greater than 20 MPa,and the leakage loss is reduced by more than 40%compared with cement plugging agent.Field tests show that the deep long-term channeling plugging technology can effectively improve the polymer flooding effect of polymer injection wells in sandstone reservoirs,and increase the production of oil wells benefiting from polymer injection.The average effective period of channeling sealing is more than one year.