New technique for access-borehole drilling in shelf glaciers using lightweight drills

This paper describes a new, environmentally friendly drilling technique for making short-and long-term access boreholes in shelf glaciers using lightweight drills. The new drilling technique was successfully developed for installation of small-diameter sensors under the Ross Ice Shelf through ~ 193 m thick ice at Windless Bight, McMurdo Ice Shelf, Antarctica. The two access boreholes were drilled and sensors installed in 110 working hours. The total weight of the drilling equipment including the power system and fuel is <400 kg. Installation of small-diameter sensors was possible for 1.8– 6 hours after penetration through the glacier into the sea water beneath. The new drilling technique does not require drilling fluid and therefore has minimal environmental impact. It should permit access through ice-shelf ice up to 350 m thick, or glaciers on grounded ice or subglacial lakes if there is no water-permeable interface at the base. Modifications, presented in this work, of the drilling equipment and protocol will allow for (1) ~ 21 working hours for penetration through 200 m of ice, (2) installation of sensors up to 120 mm in diameter and (3) drilling long-term open boreholes through 400 m thick ice in 100 working hours.

Raw project data is available by contacting [e-mail]

本文详细介绍了利用轻便钻机在大陆架上实施短期与长期进路钻孔的新型环保钻探技术。该技术成功应用于在南极洲麦克默多冰架的Windless Bight区域，穿过罗斯冰架下约193米厚的冰层，用于安装小直径传感器。两个进路钻孔的钻探与传感器安装耗时共计110个工作小时。包括动力系统和燃料在内的钻探设备总重量不足400公斤。穿透冰川进入海水的传感器安装可在穿透冰川后1.8至6小时内完成。该新型钻探技术无需使用钻探液，因而对环境的影响降至最低。它允许通过厚度达350米的冰架冰层进行进路，或者在无水渗透界面的情况下，钻探固定在冰面上的冰川或冰川下湖泊。本研究中提出的钻探设备和协议的改进，将实现以下功能：（1）在冰层中穿透200米所需的工作时间约为21小时，（2）安装直径可达120毫米的传感器，（3）在100个工作小时内钻探穿过400米厚冰层的长时期开放钻孔。有关原始项目数据，可通过联系[e-mail]获取。