美国页岩气压裂返排液处理技术现状及启示

水力压裂技术是目前页岩气开发依靠的主要储层改造手段，但采用该技术开采页岩气对水资源的消耗情况和压裂施工完成后返排液如何处置则引起了人们广泛的关注。为此，以美国Marcellus页岩区和Barnett页岩区为例，分析整理了其压裂返排液的水质特点与处置方式。在系统归纳美国页岩气开发过程中形成的返排液管理路线的基础上，从处理回用和处理外排两个方面介绍了返排液处理技术现状及研究进展。结论认为：从目前国外应用和研究现状来看，页岩气压裂返排液处理的理论和技术是相对成熟的。进而结合我国页岩气开发的形势，提出了符合实际的压裂返排液处理技术研究框架，明确了研究主题，提出了研究方向和目标建议：①完善页岩气压裂返排液深井灌注技术标准体系；②开展页岩气压裂返排液处理回用技术研究，研发耐盐耐硬度压裂液体系及配方；③开展其他废水回用配制页岩气压裂液体系或无水压裂可行性研究；④探索压裂返排液外排技术应用的可能性。以期为上述热点问题的最终解决提供技术思路。

Status quo of fracturing flowback fluids treatment technologies of US shale gas wells and its enlightenment for China

Hydraulic fracturing treatment is an important simulation means of shale gas extraction; however, the disposal of huge amounts of water and flowback fluids arouses public concern. Therefore, in the case studies of the Barnett and Marcellus Shales in the United States, this paper analyzed and summarized the unique water quality features of flowback fluids and their disposal modes. Then, based on a summary of the management strategies on flowback fluids and in the US shale gas extraction process, the widely concerned issues and disposal techniques were introduced in the respect of post frac treatment for recycle use and for disposal, which have been proved to be mature enough in terms of theory and technical application. Moreover, under the present situation of shale gas development in China, We presented the following directions and proposals for our further research on the disposal of the used water and flowback fluids after hydraulic fracturing treatment: (1) to improve the deep well injection technology system for flowback water disposal; (2) to conduct technical studies of the reuse of flowback water and to develop high salinity and hardness tolerant fracturing fluids; (3) to test the feasibility of employing other wastewater in preparing fracturing fluids and of adopting waterless fracturing treatment in shale gas exploration and development; (4) to explore the possibility of treating the flowback water for discharge. These studies will provide an idea of finding better solutions in this field.