致密气压裂返排液处理回用技术现场应用研究

Field Application Research on Reuse Treatment Technology of Tight Gas Fracturing Backflow Fluid

为实现压裂施工作业水资源的循环利用,避免造成环境污染,针对致密气压裂返排液的处理回用配液技术进行现场应用研究。压裂返排液经过脱稳、絮凝沉淀、定位除杂质、成分调节、精细过滤等工艺处理后可作为现场配液用水。该技术应用在山西致密气开采现场,对经处理后返排液配制的压裂液进行基液黏度、交联时间、流变性能(抗温抗剪切性能)、静态滤失性、破胶时间及破胶黏度等指标评价,各项指标均满足行业标准要求。同时,压裂液作为前置液和携砂液在LX-160-2D井压裂应用,施工作业压力平稳,携砂顺畅,压裂施工作业顺利完成。从节省现场用水成本以及降低废液处理成本两方面来看,使用返排液回用配液,可获得可观的经济效益。

In order to realize the recycling of water resources in fracturing construction operation and avoid environmental pollution,the research on reuse treatment technology of fracturing backflow fluid in tight gas is conducted.After destabilization,flocculation and sedimentation,positioning and removal of impurities,composition adjustment,fine filtration treatment,etc.,fracturing backflow fluid can be used to prepare fracturing fluid in the field.The technology is applied in a tight gas exploitation field in Shanxi Province,the fracturing fluid prepared by the treated backflow fluid is evaluated in base fluid viscosity,crosslinking time,rheological properties(temperature and shear resistance),static filtration property,and gel breaking time and viscosity,and all indicators meet the requirements of industry standards.Meanwhile,the fracturing fluid is used as a pre-fluid and sand carrying fluid in the fracturing process of LX-160-2D Well.The pressure of construction operation is stable,the sand carrying is smooth,and the fracturing construction operation is successfully completed.From the perspective of comprehensively saving on-site water costs and reducing waste liquid treatment costs,considerable economic benefits can be obtained by using the treated backflow fluid for recirculation.