稠油产出水深度处理回用于热采锅炉的中试研究

Pilot study on recycling produced water from heavy oil recovery to thermal boiler

对稠油产出水回用于热采锅炉进行了现场中试研究 ,确定了工艺流程和设计参数 ,并对软化工艺的选择、硬度、二氧化硅、悬浮物、总铁的去除以及运行成本和经济效益进行了分析讨论。当 pH值控制在 8 5～ 9 5 ,MgCl2 的投加量为 2 0 0mg/L时 ,混凝沉降罐出水中二氧化硅、总硬度和总铁量可分别降至 40mg/L、70mg/L和 0 0 5mg/L以内。强酸树脂和弱酸树脂对硬度的去除效果都很好 ,但对二氧化硅的去除效果均不明显。与弱酸树脂相比 ,强酸树脂再生周期长、运行简单、成本较低。稠油产出水经混凝沉降罐、双滤料过滤器和强酸钠离子交换器处理后可回用于热采锅炉。

The water produced from heavy oil recovery was treated and recycled to thermal boilers.Its field pilot was conducted.The technology process and parameters for the produced water recycled to the thermal boiler were presented.The selection of softening process,reduction of hardness and removal methods of silica,suspended solid and total ferrous concentration were analyzed.The disposal cost and cost benefit were discussed.After coagulation and sedimentation,the concentration of silica in the produced water was below 40 mg/L,and the tatal hardness was less than 70 mg/L,and the total ferrous concentration was below 0.05 mg/L when pH value was controlled in the range of 8.5 to 9.5 and the concentration of MgCl 2 additive was 200 mg/L.The strong and weak resins could effectively reduce the hardness of the produced water,but couldn't evidently remove silica.Compared with the weak resin,the strong resin had the characteristics of long regeneration period,simple operation and low cost.The field pilot tests demonstrated that the produced water treated in coagulation and sedimentation tank,dual mediums filter and strong acid resin exchanger could be recycled to the thermal boiler of oilfield.