极地深冰心钻探“暖冰”层钻进技术难点及对策

Analysis of the Technology Difficulties and Countermeasures in Warm Ice Deep Core Drilling

极地冰心分辨率高、记录时间尺度长、信息包含量大,直接记录着远古时期的大气组成,蕴藏着珍贵的古气候和古环境信息,获得年代久远的深冰心,对于重建地球的历史演化以及预测全球气候、环境的变迁具有重要意义。因此,世界各国都在竞相寻找年代久远的冰心,开展深冰心钻探工程。实践表明,由于极地冰盖深部"暖冰"层冰的熔点低而温度高,某些冰层的温度接近甚至达到冰的压力熔点,以至钻进速度慢、取心率低、卡钻事故频发。详细介绍了极地深冰心钻探"暖冰"层钻进实践,深入分析了"暖冰"层钻进存在的技术问题,对钻具回转切削产生的切削热对钻进的影响进行了探讨,据此提出了"暖冰"层钻进技术对策以及今后的研究方向,以期为我国即将开展的深冰心钻探工程和冰下基岩取心钻探工程提供一定借鉴。

The ice core in Polar regions contains precious ancient climate and environment information,records the ancient atmospheric composition,and have characteristics of higher resolution,long time scale and amount of information and so on. It is very important to obtain ancient deep ice core to reconstruction the earth evolution and to predict the global climate changing. Therefore,the scientists in world are looking for ancient ice core and planning to carry out new deep ice core drilling projects. However,there are lots of problems when drilling in warm ice since the ice having lower melting point and higher temperature such as the slowly drilling speed,the lower core recovery and more sticking accidents and so on. So the warm ice drilling practices in Polar Regions are reviewed in this paper. And the technology problems drilling in warm ice are analyzed. At the same time,the influences of the cutting heat generated in the rotary drilling on drilling process are discussed. Based on these analyses,the research directions in future and the technical countermeasures for warm ice drilling are also put forward in this study,which may be provide some reference for our coming deep ice core drilling project and the subglacial bedrock core drilling project in Antarctica.