实现页岩气“绿色”开发的配套工艺技术体系

摘要

In the commercial shale gas production in Siehuan and Chongqing areas,waste water,exhaust gas,debris,especially oil cuttings,noise will be inevitably produced and even water and soil loss will be resulted in.Therefore,how to prevent the above environmental risk sources and ensure the green development of shale gas will be a great issue at present.In view of this,we collected and summarized the environmentally friendly technologies in series achieved in the commercial production practices in the Changning-Weiyuan shale gas national demonstration zone operated by the PetroChina.(1) A zoned separate sewage system and real-time disposal and reclamation of debris and drilling-fluid wastes while drilling are successfully applied to ensure the smooth drilling and production on well sites.(2) Environmentally friendly fracturing fluids are optimally selected and the fracturing flow-back fluids are recycled to achieve the goal of fracturing environmental management.(3) Such countermeasures as construction of a matched well-like production platform,noise reduction by the "electricity changed from oil" process,promoting environmentally friendly drilling technologies,and formulating a full environment evaluation program,etc.,to further mitigate the risks in environmental damage and pollution.Field practices demonstrated that starting from the source of any produced wastes and focusing on operation process control & end pollution treatment have helped to obtain good results in wastes reduction,harmless discharge,resources cyclic utilization,etc.Finally,it is concluded that the above adopted pollution control and green development technological series will be effective to promote the sustainable development of shale gas in this national demonstration zone.%在川渝地区页岩气产能建设过程中,不可避免地会产生大量的废水、废气、废渣(特别是含油岩屑)和噪声,并且还有可能造成水土流失.如何防治上述环境风险源、确保页岩气的“绿色”开发,是一个重大难题.为此,总结了中国石油天然气集团有限公司在长宁-威远国家级页岩气产业示范区开发实践中形成的系列环保技术体系:①采用井场清污分流系统、钻井液不落地技术、随钻实时处理工艺和岩屑资源化利用技术保障钻井清洁生产;②优选环保型压裂液、对压裂返排液进行循环利用,从而实现压裂环保管理;③配套平台化作业实现“井工厂化”、实施油改电降噪音、推行环保钻井工艺、制订全面的环境评价方案等措施,进一步降低环境污染的风险.实践证明,页岩气清洁生产工艺从废弃物产生源头入手,加强作业过程控制、末端污染治理,则可实现废弃物减量、无害化、资源化的目标.结论认为,采用上述污染防治和“绿色”开发配套技术,可以有效促进该区页岩气的可持续开发.