Document DetailsDirectional Drilling
|Authors:||Zagorodnov VS, Kelley JJ, Koci B, Stanford KL, and Collins J|
Directional Drilling (DD) technology can be used in deep glacier boreholes to obtain additional ice cores from any depth and to create supplemental boreholes for geophysical research on glacier ice properties. Experimental directional drilling was done using an antifreeze thermo-electric drill in a test well. The test demonstrated that a whipstock deployed in the main borehole permits slant drilling to obtain extra ice cores. The whipstock was placed 25 cm above the bottom of the 4.5 m deep borehole. The antifreeze thermal drill was inclined in the cavity to an angle of up to 3 degrees. When the second borehole reached a depth of about 6m from the whipstock it had no inclination. The distance between the axes of the main and secondary boreholes was about 0.3 m. The whipstock was frozen into the main borehole during slant drilling and afterwards, it was heated electrically and removed from the hole.