CO_2驱复合凝胶封窜剂微观结构及配方优化

Microstructure and Formula Optimization of CO_2 Flooding Composite Gel Channeling Sealing Agent

为了获得性能优良的超临界CO_2复合凝胶,通过L_(16)(4~4)正交实验研究了CO_2分压、反应温度、反应时间、硅酸钠质量浓度4个因素对无机凝胶生成量的影响规律,在超临界CO_2条件下利用硅酸钠溶液复配丙烯酰胺体系制备无机-有机复合凝胶,通过环境扫描电镜分析了无机凝胶、有机凝胶、复合凝胶的微观结构。结果表明:无机凝胶的适宜反应条件为反应压力9.0 MPa、反应温度32.0℃、反应时间14.0 h、硅酸钠质量分数4.0%;在超临界CO_2条件下,无机凝胶颗粒均匀地穿插在有机高分子网络结构中,有利于增强复合凝胶强度。

In order to obtain the composite gel with excellent performance in the supercritical CO2 state, through the L16 （4^4） orthogonal experiment, the influence of CO2 pressure, reaction temperature, reaction time and sodium silicate concentration on inorganic gel production were studied. Under the condition of supercritical CO2, the inorganic and organic composite gel system was prepared from the mixture of sodium silicate solution and acrylamide, the microscopic structure of inorganic gel, organic gel, composite gel was observed through the environmental scanning electron microscopy （ESEM）. The results showed that, The appropriate conditions of inorganic gel were as follows, the reaction pressure was of 9.0 MPa, the reaction temperature was 32.0℃, the reaction time was 14.0 h and the sodium silicate mass fraction was 4.0%. In supercritical CO2, inorganic gel particle equably dispersed in organic gel network structure, which was beneficial to enhance the strength of the composite gel.