油田压裂返排液处理技术研究进展

Research Progress in Treatment Technology of Fracturing Backflow Fluid in Oilfields

压裂作业是油田开发的重要手段,近年来随压裂规模的增加,压裂返排液量逐年增加。压裂返排液成分复杂,具有COD含量高、黏度高、悬浮物含量高、稳定性强、处理难度大等特征。压裂返排液中含有大量的有机污染物以及金属离子,如直接排放环境中可对水体和土壤产生严重的污染,经过生物富集和传递最终危害人类健康。油田常用压裂返排液处理技术主要有固化法、混凝法、微电解法、生物法、膜方法、氧化法等。根据上述方法的原理、处理效果,并对比以上技术的优缺点,提出今后压裂返排液处理技术的主要发展方向为:研究绿色化学处理剂,优化现有工艺,研究新技术新方法,开辟多种利用途径,从而为今后压裂返排液资源化利用提供借鉴。

Fracturing operation is an important means of oilfield development.The amount of fracturing backflow is increasing year by year with the increase of fracturing scale.Fracturing backflow fluid has complex components,with large backflow displacement,high COD,high viscosity,high suspended solids content,strong stability,and difficult treatment.There are a lot of organic pollutants and metal ions in the fracturing backflow fluid.It can cause serious pollution to water and soil if it is directly discharged into the environment,and eventually it will endanger human health through bioaccumulation and transmission.The commonly used fracturing backflow fluid treatment technologies in oilfields include solidification method,coagulation method,micro electrolysis method,biological treatment method,membrane method,and oxidation method,etc.The principle and treatment effect of the above methods are analyzed,and their advantages and disadvantages are compared.The main development direction of fracturing backflow fluid treatment technology in the future is put forward,namely researching the green chemical treatment agent,optimizing existing technologies,researching new technologies and methods,and exploring new utilization ways.It can be used as a reference for the resource utilization of fracturing backflow fluid in the future.