关键词: 超细水泥, 缓蚀剂,  , 降失水剂, 消泡剂, 力学形变性能

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