冰层空气反循环快速钻进方法及冰屑运移研究

Study on transportation of ice chips in ice drilling with air reverse circulation

摘要:

空气反循环钻进技术具有钻速快、能耗低、可不提钻连续取心取样、能有效避免积雪层漏失等优点，在冰层钻探中极具应用潜力。本文针对冰层钻探技术特点，提出了双壁钻杆式、双通道高压胶管式和寄生高压胶管式等3种空气反循环冰层钻探技术，分别介绍了其工作原理及特点。基于气力输送和气体钻井基本理论，对冰屑颗粒气体介质中的悬浮速度进行了分析，建立了单颗粒冰屑悬浮、运移方程和冰屑颗粒群悬浮方程，并设计了冰屑悬浮实验台，对冰屑悬浮所需的风速进行了实验测试。理论计算值与实验实测值吻合较好，最大误差约10.91%，结果表明冰屑粒径、冰屑密度和风量是影响其悬浮和上返速度的关建因素。可用本文建立的冰屑运动方程来计算实际钻进时携带冰屑所需的风量，为后续在极地实施冰层空气反循环钻进技术提供了依据。

Abstract:

Air reverse circulation drilling technology， which has advantages of fast drilling speed， low energy consumption， continuous core sampling without tripping and effective prevention of circulation loss in snow cover， sees great potential application in ice drilling. In view of the characteristics of ice drilling technology， this paper proposes three kinds of air reverse circulation ice drilling techniques， including dual-wall drill pipe， double channel high pressure hose and parasitic high pressure hose； and describes their working principles and characteristics respectively. Analysis is made of the suspension velocity of ice particles in air medium with the suspension and transport equations for both the single ice particle and the particle group established under the guidance of pneumatic transportation and gas drilling theory. Meanwhile， the experimental bench was designed to test the air speed required for ice chips suspension. The calculated values are in good agreement with the measured values with the maximum difference at about 10.91%. The results showed that the ice particle size， ice particle density and air volume are the key factors affecting the suspension and up-hole velocity. The equation for ice chips movement established in this paper can be used to calculate the air volume required to carry ice chips during actual drilling， providing a basis for the subsequent implementation of air reverse circulation ice drilling technology in the polar regions.