School of Energy Resources, China University of Geosciences, Beijing, 100083, China,
Environ Sci Pollut Res Int. 2014;21(11):6964-74. doi: 10.1007/s11356-014-2675-4. Epub 2014 Mar 7.
As one of the unconventional natural gas family members, coalbed methane (CBM) receives great attention throughout the world. The major associated problem of CBM production is the management of produced water. In the USA, Canada, and Australia, much research has been done on the effects and management of coalbed methane produced water (CMPW). However, in China, the environmental effects of CMPW were overlooked. The quantity and the quality of CMPW both vary enormously between coal basins or stratigraphic units in China. The unit produced water volume of CBM wells in China ranges from 10 to 271,280 L/well/day, and the concentration of total dissolved solids (TDS) ranges from 691 to 93,898 mg/L. Most pH values of CMPW are more than 7.0, showing the alkaline feature, and the Na-HCO3 and Na-HCO3-Cl are typical types of CMPW in China. Treatment and utilization of CMPW in China lag far behind the USA and Australia, and CMPW is mainly managed by surface impoundments and evaporation. Currently, the core environmental issues associated with CMPW in China are that the potential environmental problems of CMPW have not been given enough attention, and relevant regulations as well as environmental impact assessment (EIA) guidelines for CMPW are still lacking. Other potential issues in China includes (1) water quality monitoring issues for CMPW with special components in special areas, (2) groundwater level decline issues associated with the dewatering process, and (3) potential environmental issues of groundwater pollution associated with hydraulic fracturing.
作为非常规天然气家族的一员，煤层气（CBM）受到了全世界的关注。CBM 生产的主要伴生问题是产出水的管理。在美国、加拿大和澳大利亚，对煤层气产出水（CMPW）的影响和管理进行了大量研究。然而，在中国，CMPW 的环境影响被忽视了。中国不同煤盆地或地层单元的 CMPW 数量和质量差异巨大。中国 CBM 井的单位产水量从 10 到 271280 L/井/天不等，总溶解固体（TDS）浓度从 691 到 93898 mg/L 不等。大多数 CMPW 的 pH 值都大于 7.0，呈碱性特征，中国 CMPW 的典型类型是 Na-HCO3 和 Na-HCO3-Cl。中国 CMPW 的处理和利用远远落后于美国和澳大利亚，CMPW 主要通过地表蓄水和蒸发进行管理。目前，中国 CMPW 面临的核心环境问题是 CMPW 的潜在环境问题尚未得到足够重视，相关法规和环境影响评价（EIA）指南仍缺乏。中国还存在其他潜在问题，包括（1）特殊地区 CMPW 特殊成分的水质监测问题，（2）与脱水过程相关的地下水位下降问题，以及（3）与水力压裂相关的地下水污染的潜在环境问题。
