长宁页岩气田开发地下水环境风险及防控技术研究

Research on Groundwater Environmental Risks and Prevention Measures in Shale Gas Field

长宁页岩气田地处四川盆地南缘溶洞发育区,区内人口众多,居民饮用水源以地下水为主,页岩气开发过程中地下水污染环境风险不容忽视。全面分析了页岩气开发地下水环境风险的环节和污染源,结果表明页岩气开发中的钻井、排液试气、采输及返排液回注处置等阶段为产生地下水风险的主要环节。对可能造成地下水污染的环节提出地下水防控措施,以期有助于全面把握页岩气开发地下水风险过程,为其他区块页岩气开发地下水环境保护提供示范和借鉴。

Changning shale gas field is located in a Southeast of Sichuan with developed karst groundwater and dense population.The environmental risk of groundwater pollution during the exploitation and production must be taken into consideration.This paper comprehensively analyzes and summarizes pollution processes and sources of groundwater pollution caused by shale gas development.The results show that drilling,drainage,gas testing,production and transportation as well as flow-back fluid re-injection are the main processes of shale gas development with groundwater pollution risks.In the end,the paper puts forward specific prevention and control measures for the pollution processes and sources,aiming to control the groundwater pollution process during shale gas development,thus providing demonstration and reference for the groundwater environmental protection of shale gas development in other areas.