type:P(論文)

We propose that a new type of drill, alternately known as a Fast Mechanical-Access Drill, or Coiled Tubing Drill for Ice (CTDI), be developed for polar research. The proposed drill is similar in concept to the latest coiled tubing (CT) drills used for commercial oil and gas development. CT drills use a metal or advanced-composite tube to deliver fluid downhole to a hydraulic motor that drives a cutting bit. This technique should permit drilling rates of ∿40m・(hr)^<-1> in polar ice. The bulk of the components are commercially available. The CTDI would be : a) capable of drilling through 3-4km of ice in 6-8days, including setup time, b) aircraft (LC-130) transportable and sled-mounted for rapid mobilization/demobilization, c) able to drill an array of deep boreholes in a single season. d) able to produce semi-permanent uniform-diameter holes with minimal thermal disturbance, e) capable of acquiring rock cores, frozen sediment cores, and short ice cores, f) sufficiently modular and flexible by design that new tools can be added to satisfy future research needs. The capabilities of the CTDI would fill the void between existing deep ice-core drills and hot-water drills. It is believed the new drilling system would greatly enhance several lines of current research, as well as allow the pursuit of new scientific investigations that are not currently feasible. The CTDI could be used by the research community to help address outstanding questions concerning the Earth's climate system, the history and dynamics of ice sheets, the geology and tectonics of polar regions, and the biology within and beneath polar ice sheets. Finally, we discuss access drills for investigating conditions within Antarctic subglacial lakes.