铬冻胶与高渗油藏窜流通道强度的适应性研究

中高渗油藏经过长期注水开发,储层物性发生了变化,导致注入水沿着高渗透带形成不同强度的窜流通道,严重影响开发效果。针对现场常用的铬冻胶,通过动态封堵实验研究了不同聚合物浓度（3 000 mg/L 和5 000 mg/L）铬冻胶体系在不同渗透率窜流通道中的注入、封堵性能及驱油效果,并引入了拟阻力系数和拟残余阻力系数,分析了铬冻胶与窜流通道强度的适应性。实验结果表明,聚合物浓度越高,冻胶的注入性能越差,但是封堵性能以及调剖增油效果越好;窜流通道渗透率越高,冻胶封堵强度越弱,而调剖增油效果越差;铬冻胶对3 D、5 D、10 D、50 D 的窜流通道适应性较好,对于100 D、150 D、200 D 的窜流通道适应性较差。该研究结果为铬冻胶应用于现场封堵高渗油藏窜流通道提供了参考依据。

Adaptability of chromium gel to the strength of crossflow channel in high permeability reservoir

After a long-term waterflooding development, physical properties of the medium-high permeability reservoir have changed, resulting in the formation of injected water crossflow channels with different strengths along the high permeability zones,which seriously affects the development effect. In this paper, a dynamic plugging experiment were conducted to identify the injection,sealing capacity and displacement effect of chromium gel system (which is usually used on site) with different polymer concentrations (3000 mg/L and 5000 mg/L) in crossflow channels with different permeabilities. Moreover, pseudo-resistance factor and pseudo-residual resistance factor were adopted to analyze the adaptability of chromium gel to crossflow channel strength. The experimental results show that the higher the polymer concentration, the poorer the injectivity of gel, but the better the sealing capacity and the profile control and oil increasing effect. The higher the permeability of crossflow channel, the weaker the sealing strength of gel, and the poorer the profile control and oil increasing effect. The chromium gel is efficiently adaptable to 3 D, 5 D, 10 D and 50 D crossflow channels, but ineffectively adaptable to 100 D, 150 D and 200 D crossflow channels. The results can provide reference for using chromium gel to plug crossflow channels in high permeability reservoir.