“自从去年所有井站蓄水池完成互连互通后，压裂返排液的重复利用率显著提升，对企业实现绿色环保、节约水资源具有重要意义。”6月3日，长城钻探四川页岩气项目部威远作业区副区长温亚向记者透露这一喜讯。截至5月底，四川页岩气项目部重复利用压裂返排液36.36万立方米，利用率达97.8%，成了公认的“节水标兵”。

页岩气井压裂施工用水量大，且压裂液从井底返排后，需拉运至处理站处理，不仅对环境带来污染风险，而且造成了人力、财力和水资源的浪费。为高效重复利用压裂返排液，四川页岩气项目部组建专家团队深入现场调研，全面梳理各井站地理位置和出液量情况，采用修筑定制化蓄水池、安装水泵、铺设连通管线的方式，建成一套井站间可双向灵活调配的压裂供水返排系统。截至目前，累计修筑蓄水池容积超15万立方米，铺设供水管线50余公里，成功实现各井站水池互连互通。同时，引进10个移动式多边形储液罐，便于灵活调配，最大程度减少因前期征地、修筑蓄水池等影响压裂施工进度的问题。

在供水返排系统管理方面，四川页岩气项目部建立水池液位安全智能预警系统，利用计算机自动采集现场数据，遇到危险及时报警，实现从人工巡检向实时监控转型，避免了废水外溢的风险。开展“金点子”合理化建议征集等主题活动，深挖节支降耗潜能，根据水池泵站使用规律，对各站变压器进行间开、销户和减容处理，节省电费支出。充分发挥部分水池泵站地势高的优势，利用虹吸原理使压裂返排液自吸倒运，减少能源消耗和设备磨损。

在满足自身蓄水的同时，四川页岩气项目部还加强与西南油气田、川庆钻探等9家页岩气开采单位协作，搭建压裂返排液共享平台，有效保障了川渝地区页岩气新平台压裂用水供应，为推进各单位互助共赢和实现页岩气绿色环保开发奠定了基础。

"Since all wellstation reservoirs were interconnected last year, the reuse rate of frac flowback fluids has increased significantly, which is of great importance for companies to achieve green environmental protection and water conservation." On June 3, Wen Ya, deputy director of Weiyuan Operation area of the Great Wall Drilling Sichuan shale gas Project Department, revealed the good news to reporters. As of the end of May, the Sichuan shale gas project Department had reused 363,600 cubic meters of fracturing flowback fluid, with a utilization rate of 97.8%, becoming a recognized "water-saving pacesetter".

Fracturing operation of shale gas Wells requires a lot of water, and fracturing fluid needs to be transported to the treatment station after returning from the bottom of the well, which not only brings pollution risk to the environment, but also causes waste of human, financial and water resources. In order to efficiently reuse fracturing flowback fluid, Sichuan Shale Gas Project Department set up an expert team to conduct in-depth on-site investigation, comprehensively sorted out the geographical location and liquid output of each well station, and built a set of fracturing water flowback system that can be flexibly deployed between well stations by constructing customized reservoirs, installing pumps, and laying connecting pipelines. Up to now, the accumulated volume of the reservoir has exceeded 150,000 cubic meters, and more than 50 kilometers of water supply pipelines have been laid, successfully realizing the interconnection of the well station pools. At the same time, 10 mobile polygonal liquid storage tanks are introduced to facilitate flexible deployment and minimize the problems that affect the progress of fracturing construction due to early land expropriation and construction of reservoirs.

In terms of water supply backflow system management, Sichuan Shale gas project Department has established an intelligent early warning system for the safety of water tank level, which uses computers to automatically collect on-site data and timely alarm danger, realizing the transformation from manual inspection to real-time monitoring and avoiding the risk of wastewater spillovers. Carry out theme activities such as "Golden idea" rationalization proposal collection, dig deep the potential of saving expenditure and reducing consumption, and carry out inter-opening, account cancellation and capacity reduction treatment of transformers at each station according to the use law of the pool pump station to save electricity expenses. Give full play to the advantages of high terrain of some pump stations, use the principle of siphon to make the fracturing flowback fluid self-suction and reverse transport, reduce energy consumption and equipment wear.

While meeting its own water storage, Sichuan Shale Gas Project Department also strengthened cooperation with 9 shale gas mining units such as Southwest Oil and Gas Field and Chuanqing Drilling to build a sharing platform for fracturing return fluid, effectively guaranteeing the supply of fracturing water for new shale gas platforms in Sichuan and Chongqing, and laying a foundation for promoting mutual assistance and win-win cooperation among all units and realizing green and environmentally friendly development of shale gas.