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深冰层取心钻探是极地科学考察的重要组成部分。在极地勘探取样过程中做到在获得高质量冰岩心样品的同时,将钻井液对极地环境的污染降低到最低程度,对保护极地原生环境具有重要意义。依据南极科学钻探的地层条件,应用Visual Modflow建立了污染物在雪层中的运移模型,在污染物浓度保持恒定时,对钻孔内污染物进行了数值模拟,预测了10年后污染物在雪中污染羽扩散范围。在此基础上,对比分析了不同弥散系数时,雪对污染物弥散的能力。极地科学钻探使用的钻井液粘度通常是水的10倍,随着污染物粘度的增大,其扩散的距离也将相应减少。研究结果为深入开展极地冰层取心钻探钻井液对极地环境影响评价研究奠定了重要的理论与技术基础。
Deep ice core drilling is an important part of polar scientific investigation. During the process of polar exploration and sampling, it is of great importance to protect the polar environment because it can obtain high quality samples of ice core while minimizing the pollution of the drilling fluid to the polar environment. According to the stratigraphic conditions of Antarctic scientific drilling, the model of pollutant migration in snow layer was established by using Visual Modflow. When the pollutant concentration remained constant, the pollutants in the borehole were numerically simulated. After 10 years, the pollutants Contamination in the snow spread of feathers. On this basis, the ability of snow to disperse contaminants was compared and analyzed with different diffusion coefficients. The viscosity of drilling fluid used in polar scientific drilling is usually 10 times that of water. As the viscosity of pollutants increases, the diffusion distance will also decrease accordingly. The results of this study laid an important theoretical and technical foundation for further research on polar environmental impact assessment of drilling fluid for polar ice core coring drilling.