Abstract: The high water cut oil wells were unable to product normally because of the existance of fracture and natural microfracture in the low permeability fractured reservoir. In order to avoid the injected water going across to the old seam of oil wells in the process of water flooding and enhancing the sweep efficiency and oil recovery, the superfine cement plugging technology was put forward. Based on the optimization of water cement ratio of superfine cement, the concentration of corrosion inhibitor, reducing agent and defoaming agent in the plugging system was optimized, and the mechanical deformation capacity was also evaluated. The results showed that the optimum water cement ratio of superfine cement was 0.7 and the optimum cement slurry was the mixture of 800 head superfine cement, 0.4% corrosion inhibitor, 0.5% reducing agent and 0.5% defoaming agent. Because of the double efficacy of plasticizing and toughening, the slurry system had good mechanical deformation capacity and the flexural strength reached 48.9 MPa. This can completely met the plugging strength requirements in the field. This system has good application prospect in the old seam plugging of oil well in the fractured reservoir.

Key words: Superfine cement,    ,  Corrosion inhibitor,    ,  Reducing agent,    ,  Defoaming agent,    ,  Mechanical deformation capacity

摘要： 低渗裂缝性油藏由于压裂裂缝及天然微裂缝的存在, 油井大量出水, 已无法正常生产, 为了避免水驱 过程中注入水沿老缝水窜至油井, 提高注入水波及效率和原油采收率, 提出老缝超细水泥封堵技术。在超细水泥浆 水灰比优化的基础上, 对封堵体系中的缓凝剂、 降失水剂以及消泡剂加量进行优化, 最后通过加入纤维, 评价了纤维 水泥石的力学形变性能。结果表明, 超细水泥的最佳水灰比为0. 7, 优选出的超细水泥封堵剂的最佳配方为: 8 0 0目 超细水泥+0. 4%缓凝剂+0. 5%降失水剂+0. 5%消泡剂。由于改性纤维的增塑和增韧的双重功效, 使得水泥石具有 很好的力学形变性能, 1 5d抗压强度高达4 8. 9MP a, 完全能满足矿场封堵强度的要求。该体系在低渗裂缝性油藏中 的油井老缝封堵中具有很好的适应性。

关键词: 超细水泥, 缓蚀剂,  , 降失水剂, 消泡剂, 力学形变性能