四川盆地南部地区页岩气开发及其减污降碳再认识

Recognition on shale gas development and its pollution and carbon reduction in the southern Sichuan Basin

为助推中国页岩气持续高质量发展,在溯源页岩气环境争议的基础上,结合四川盆地南部地区(以下简称川南)十余年来页岩气开发实践,总结了国内对页岩气开发生态环境影响的新认识,系统介绍了中国自主创新形成的页岩气清洁开采技术,并指明了下一步技术发展的方向。研究结果表明:①页岩气环境问题的广泛关注始于2009—2011年,经过激烈讨论,美国学术界主流意见认为,页岩气开发存在生态环境风险,但通过合理取水、确保井筒质量、妥善贮存和处置压裂返排液及钻井固体废物等措施可有效防范;②页岩气开发对中国温室气体排放量贡献有限,不会必然污染地下水环境,绿色开发应重点关注低碳钻井和压裂、废弃物处置、地下水保护等方向;③“电代油”钻井和压裂实现了施工过程无直接温室气体排放,川南页岩气压裂返排液在处理回用基础上已实现处理外排,油基岩屑处置对规模开发的制约也因热脱附技术的进步而突破;④页岩气清洁开采技术仍应在深度降碳、稳定减污、持续增效等方面开展技术创新和管理创新工作。结论认为,基于10余年来对中国页岩气开发生态环境保护的探索与再认识,可为中国未来页岩气绿色高效开发提供有益参考和借鉴。

To promote the sustainable high-quality development of shale gas industry in China,this paper summarizes domestic new understanding of the impact of shale gas development on the ecological environment by tracing the source of the shale gas environmental controversy,combined with the practical shale gas development in the southern Sichuan over the past ten years.In addition,the clean shale gas production technologies developed independently and innovatively in China are systematically introduced,and the following technological development direction is pointed out.And the following research results are obtained.First,the environmental problems of shale gas began to attract widespread concerns in 2009-2011.After heated discussion,the American academic community reaches the mainstream opinion that shale gas development has ecological environmental risks,which can be effectively prevented by taking water reasonably,ensuring wellbore quality,and storing and disposing fracturing flowback fluid and drilling solid waste properly.Second,shale gas development makes limited contribution to greenhouse gas emissions in China and does not necessarily pollute groundwater.Its green development shall focus on lowcarbon drilling and fracturing,waste disposal,groundwater protection,and other directions.Third,"electricity replacing oil"drilling and fracturing realizes no direct emission of greenhouse gas in the construction process.The fracturing flowback fluid of shale gas in the southern Sichuan is treated and discharged based on treatment and reuse.The restriction of oil-based cuttings disposal to large-scale development is also broken through with the progress of thermal desorption technology.Fourth,the clean shale gas production technology shall still be innovated technologically and managerially from the aspects of deep carbon reduction,stable pollution reduction and continuous efficiency improvement.In conclusion,over one decade of exploration and recognition on the ecological environment protection of domestic shale gas development can provide a useful reference for the future green and efficient development of shale gas in China.