Methods for Increasing Drilling Performance of the Thermal Spallation Drilling System

摘要

Current thermal spallation drilling methods offer advantages in performance and cost over conventional rotary methods. We have analyzed the mechanics of the thermal spallation process and found that heat transfer from the hot gases to the rock is the key process for limiting better penetration rates. Increasing the operating air pressure to 1000 psi will lead to a tripling of the penetration rate to about 60 ft/hr (18 m/hr) in granitic rocks. 10 refs., 3 figs. (ERA citation 10:036417)