Butyl acetate, an alternative drilling fluid for deep ice coring projects
Gosink, T. A., J. J. Kelley, B. R. Koci, T. W. Burton, and M. A. Tumeo
Journal of Glaciology, Vol. 37, No. 125, p. 170-176, 1991

Deep-drilling operations in glaciers require a fluid to maintain hydrostatic equilibrium and prevent closure due to plastic flow of the ice. Many past practices have employed various fluid mixtures using fuel oil as the base. The case for butyl acetate is presented here as an adequately dense and environmentally sage drilling fluid. Results from the 1990 drill season are highly favorable.

Instrumentation for the PICO deep ice coring drill,
Hancock, W. H.
Ice Drilling Technology, 4th International Workshop, Memoirs of National Institute of Polar Research, Special Issue No. 49, p. 69-77, 1994

An electronic data collection and control system has been developed for the PICO 13.2 cm deep ice coring drill. It monitors a variety of drilling parameters including inclination, depth, temperature, pressure, RPM, weight and others. It also displays this data for the drill operator and allows the operator to control speed and direction of the drill motor. The display program allows setting limits on all parameters so an alarm sounds if anything goes wrong. This instrumentation package will be described and some of the data collected with it will be discussed.

Ice coring and drilling technologies developed by the Polar Ice Coring Office
Kelley, J.J., K. Stanford, B. Koci, M. Wumkes and V. Zagorodnov
Ice Drilling Technology, 4th International Workshop, Memoirs of National Institute of Polar Research, Special Issue No. 49, p. 24-40, 1994

The search for Òzero defectsÓ ice cores continues to challenge the ice coring and drilling community. No single drilling and coring device will fill all needs. Each project will have special requirements and will require an initial decision as to the most effective drilling system to be used as well as ensuring personal and environmental safety. PICO has developed several types of drilling and coring systems from a lightweight hand auger to more complicated electromechanical drills (dry and fluid-filled holes) with rock-penetrating capability and thermal drills. Logistics considerations are important, and a comparison is made between the drill types associated with system weight, expected power and drilling liquid requirements, and fuel consumption. Recent technological developments involve hot-water mechanical drilling, improvements in antifreeze and thermal drilling, the development of directional drilling, antifreeze dissolution drilling, and vibratory drilling.

Development of the U. S. deep coring ice drill
Wumkes, M. A.
Ice Drilling Technology, 4th International Workshop, Memoirs of National Institute of Polar Research, Special Issue No. 49, p. 41-51, 1994

The United States has developed a deep coring ice drill capable of retrieving 13.2 cm diameter cores 6 m long. A comprehensive discussion of the developmental factors surrounding the design, fabrication and refinement of the United States 13.2 cm deep coring ice drill is presented. Included in this paper are the various design param which defined the final configuration and approach. Technical theories and their affect on drill design are discussed. New drilling fluids for use in deep bore holes have been developed for increased safety and health benefits which impart additional problems on the synthesis of deep coring drill designs. Drill handling design problems as well as safety and environmental concerns are presented. Design evolution and modifications are discussed in detail.

Operational considerations of the U.S. deep coring ice drill.
Wumkes, M. A.
Ice Drilling Technology, 4th International Workshop, Memoirs of National Institute of Polar Research, Special Issue No. 49, p. 52-56, 1994

The development of the 13.2 cm (5.2 inch) U.S. deep coring ice drill has required new approaches to the drill operation and handling. Large diameter cores 6 m (20 feet) long have dictated a change in the scope of not only the drill handling but core handling as well. A drill handling system has been designed and refined to accommodate these large cores. New drilling fluids have re-defined operational procedures in regards to safety and environmental concerns. These new drilling fluids have also forced investigators to incorporate recycling procedures due to the high costs of the drilling fluid. These and other factors are discussed as related to drilling operational requirements.