页岩气压裂返排液达标排放执行标准及处理技术  

Treatment techniques and execution standards for achieving emissions of shale gas hydraulic fracturing flowback fluids

作　　者：熊春平[1,2] 向启贵 罗小兰[1,2] 邓皓 Xiong Chunping;Xiang Qigui;Luo Xiaolan;Deng Hao(Research Institute of Safety,Environmental Protection and Technical Supervision,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Sichuan Key Laboratory for Shale Gas Evaluation and Exploitation,Chengdu,Sichuan 610041,China;CNPC Research Institute of Safety&Environment Technology,Beijing 102206,China;State Key Laboratory for Pollutant Control and Treatment in Petroleum and Petrochemical Industry,Beijing 102206,China)

机构地区：[1]中国石油西南油气田公司安全环保与技术监督研究院 [2]页岩气评价与开采四川省重点实验室 [3]中国石油安全环保技术研究院 [4]石油石化污染物控制与处理国家重点实验室

出　　处：《天然气工业》2019年第8期137-145,共9页Natural Gas Industry

基　　金：国家科技重大专项“长宁—威远页岩气开发示范工程——页岩气开发效益评价方法及环保技术研究与应用”（编号：2016ZX05062007-001）

摘　　要：针对页岩气压裂返排液的达标排放,如果不考虑总溶解固体(Total Dissolved Solids,缩写为TDS),仅降解和去除包括高浓度化学需氧量(COD)和固体悬浮物(SS)在内的其他污染物,将极大地降低处理技术难度和处理成本,但要避免过高的TDS浓度对受纳水体的生态环境和用水安全的影响,就必须根据现有的压裂返排液中氯化物排放标准,研究在技术和经济上可行的压裂返排液达标排放处理方法和实施途径。为此,在详细梳理并分析国家标准、行业标准和地方标准对氯化物及其他无机盐排放规定的基础上,结合页岩气开发的指导性技术文件对压裂返排液处理的要求和众多文献资料的调研成果,分析了两种高含盐工业废水(循环冷却排污水、垃圾渗滤液)与压裂返排液处理的相似性,进而提出了压裂返排液“预处理+生化法”处理的技术途径。研究结果表明:①在页岩气田进入开发后期,压裂返排液无法回用时,可先在气田内预处理后按适当比例配送至集中式污水处理厂进行生化处理,达标后排放;②实例演算结果表明,非脱盐技术处理压裂返排液可实现达标排放且不会影响当地的用水安全。结论认为:①应开展压裂返排液以生化法为最终处理方式的预处理技术研究和区域内主要河流地表水体氯化物和硫酸盐的本底调查研究;②压裂返排液“预处理+生化法”处理途径依法合规,处理成本相对较低,具有技术经济可行性。In view of the standard discharge of fracturing fluids in shale gas fields,if the total dissolved solids(abbreviation for TDS)is not considered,only the degradation and removal of other pollutants,including high-concentration chemical oxygen demand(COD)and suspended solids(SS),will greatly reduce the technical difficulties and treatment costs.However,the impact should not be neglected of excessive TDS concentration in fracturing fluid on the ecological environment and water safety of receiving water body.Therefore,the regulations on chlorides and other inorganic salts discharged by national standards,industrial codes and local criteria were all sorted out and analyzed in detail.Then,combined with the requirements of guiding technical documents for shale gas development for fracturing reflux treatment,the fracturing reflux treatment as well as its similarity with two kinds of high salinity industrial wastewater,circulating cooling sewage and garbage leachate,were analyzed through numerous literatures.On this basis,the technical approach of"pretreatment&biochemical process"for fracturing flowback fluid produced in the middle and later stage of shale gas development was thus put forward.The following findings were achieved.(1)In the later development of a shale gas field,the fracturing flowback fluid unable to reuse should be pretreated before being sent in a proper proportion to a centralized sewage treatment plant for biochemical treatment so as to achieve the discharge standard.(2)Case calculation results show that using the non-desalination technology to treat fracturing flowback fluids to achieve standard discharge will not affect the local water security.Finally,proposals were put forward as follows:background investigation and research should be done on the chlorides and sulfates in the surface water of the rivers involved in the biochemical treatment of fracturing flowback fluids and the"pretreatment&biochemical process"approach with a relatively low treatment cost is of technical and economic feasibility wi

关 键 词：页岩气 压裂返排液 氯化物 无机盐 达标排放 预处理 生化法 处理技术 

分 类 号：X70[环境科学与工程—环境工程]