四川页岩气开发压裂返排液和油基岩屑处理处置探析

Flowback Treatment and Oil-based Cuttings Disposal in Shale Gas Development in Sichuan

当前,四川省页岩气开发已进入高速发展阶段。通过对自2012年以来四川省页岩气开发压裂返排液和油基岩屑处理处置情况的梳理,分析认为目前四川省压裂返排液处理和油基岩屑处置过程中存在的问题包括:返排液处理回用和回注时没有考虑可能影响地下水水质的控制指标,目前暂无排放标准完全覆盖压裂返排液中的环境风险物质等;作为危险废物,油基岩屑暂存、运输和处置存在环境隐患,加上钻井平台数量多、分布广,环保部门不易监管;对油基岩屑残渣的资源化利用处置缺乏法律法规支撑。为此,在借鉴国内外关于压裂返排液和油基岩屑管理要求的基础上,建议开展压裂返排液回用和回注环境监管体系研究,进行压裂返排液处理达标外排可行性论证,完善压裂返排液处理处置技术体系,开展油基岩屑残渣资源化利用环境可行性研究,开展高性能水基钻井液替代油基钻井液体系技术论证。

Currently, shale gas development in Sichuan Province has entered a stage of rapid development. The paper summarizes the flowback treatment and oil-based cuttings disposal in shale gas development in Sichuan since 2012 and finds the following problems: the groundwater quality control indicators are not well considered during flowback reuse or reinjection, and the discharge standards for environmentally risky substances in the flowback are absent;as oil-based cuttings are hazardous wastes, there are environmental risks in their temporary storage, transport and disposal which are not easy to be seen due to the large numbers of well pads and wide distribution;and there is a lack of laws and regulations to support the resourceful utilization of oil-based debris residue. Therefore, on the basis of drawing lessons from domestic and foreign requirements for flowback treatment and oil-based cuttings disposal management, it is suggested to carry out the research on the environmental management system of reuse and reinjection of flowback, to conduct the environmental feasibility study on the discharge of flowback after treatment, to improve the technical standards for the reuse, reinjection and treatment of flowback, to carry out the environmental feasibility study on the resourceful utilization of oil-based debris residue, and to test the feasibility of using high performance water-based fracturing fluid to replace the oil-based fracturing fluid.