杭锦旗气田开发污染物对地下水环境影响

摘要

在分析杭锦旗气田区浅层地下水化学特征及其形成作用的基础上,定性评价气田开发可能产生的污染物对地下水环境的影响,同时利用GMS软件模拟预测气田开发污染物在地下水环境中的运移规律,最后提出相应地防范措施.结果表明:①杭锦旗气田区浅层地下水局部矿化度偏高,集中于地下水埋深较浅区域,地下水离子以Na+和HC03为主,地下水化学形成以岩石风化溶解为主;②气田开发间接影响地下水水化学形成,气田水渗入浅层地下水影响阳离子交换作用从而改变地下水环境.气田开发产生的钻井液、气田水可能会使浅层地下水水质变差,气田开发过程采取有效防护措施后对地下水环境影响很小;③模拟预测结果显示,各污染源泄漏工况下,地下水中污染物均具有预测期内浓度低、污染范围小的特征,经采取一定保护和防渗措施,研究区地下水环境可以达到相关标准,同时应该加强甲醇污水处理厂的防渗和生产管理,双管齐下,确保避免地下水污染.%To analyze the chemical characterisitics and the formation mechanism of shallow groundwater in the Hangjing Banner gas field,this paper qualitatively evaluates the impacts of pollutants produced by gas field development on the groundwater environment,the GMS software simulates the migration law of pollutants in the groundwater environment,and also the corresponding preventive measures are proposed.Based on the new results,the authors suggest that:① Shallow groundwater in the study area locality has high mineralization which concentrated in groundwater depth is shallow.Moreover the major ion of shallow groundwater are Na+ and HCO~,the formation of groundwater chemistry is mainly composed of rock-weathering.② The exploitation of gas will indirectly affect the groundwater chemistry,and gas field water infiltrate in the shallow groundwater which influences the cation exchange to change the groundwater environment.The drilling fluid and gas field water may cause the quality of shallow groundwater to be deteriorated.After taking effectively protective measures,the gas field development has little impact on the environment of groundwater.③ As a result of the simulation,the leaking of each pollutant has low concentration and low pollution scope in the predicted period.The standards of groundwater environment can be achieved after taking protective and anti-seepage measures.The seepage and production control of methanol wastewater treatment plant should be reinforced,both of those can ensure to avoid the contamination of groundwater.