快速获取高质量冰芯和钻孔，对全球气候变化及其它冰芯科学研究具有重要意义。冰层空气反循环钻进技术具有钻速快、能耗低、可不提钻连续取心、能有效避免积雪层循环漏失等优点，在冰层钻探中极具应用潜力。而气体介质能否将大尺寸冰芯连续不断地携带至地表以及取心状态下能否形成强力的反循环是决定该技术成功与否的关键，目前尚无相关理论或经验可以借鉴。本项目拟运用理论计算、数值模拟和实验测试等手段，分析冰芯、冰屑在气体介质中的悬浮和运移规律，探讨冰屑颗粒碰撞机理，分析其团聚的可能性及对钻进安全的影响，建立冰芯、冰屑运移方程，获得空气反循环钻进钻孔净化理论模型；探索冰芯影响和干扰下的反循环形成机制及影响因素，确定取心条件下形成强力反循环的原理和方法；建立孔深、孔径、取心尺寸与供风量等参数之间的关系模型，确定冰层空气反循环钻深能力和钻进工艺，为研发冰层空气反循环连续取心钻进技术和钻探装备提供理论依据和技术支撑。

For global climate change research and other studies, it is important to obtain high quality ice core or to drill borehole with high speed in ice sheet. Drilling with air reverse circulation is considered as one of the most promising technology in ice core drilling, especially in firn-ice drilling, since it has many advantages in promoting the penetration, lowering the power consumption, recovering ice core without lifting drill tools, preventing air circulation lost, etc. The effectiveness of this technology depends on whether or not the ice chips and ice cores can be carried up to the surface continuously through the central channel of the drill tools, and whether the reverse circulation can be formed under the condition of ice core disturbing. Little relevant theory study or engineering experience can be referred. In order to solve these problems, the suspending and transporting characteristics of ice core and ice chips under the condition of air reverse circulation will be analyzed in this project by theory calculation, CFD simulation and testing. The collision mechanism between ice chips will be discussed to study the possibility of ice chips agglomeration and its influence on drilling safety. So that the transportation equation of ice core and ice chips will be established, and the borehole cleaning theory model will be confirmed. In addition, the principle and method of forming strong reverse circulation will be determined by studying the formation mechanism and its influential factors under the conditions of ice core existing. The relationship between borehole depth, borehole diameter, ice core diameter and air flow rate and pressure will be developed, which is important to confirm the drilling ability and the drilling parameters of air reverse circulation drilling in ice. The achievements of this project will provide important theory foundation and technical support for developing rapid ice core drilling technology and drilling equipment with air reverse circulation.