Drilling Fluids for Deep Coring in Central Antarctica

Deep ice drilling requires a fluid with a density closely matched to that of the ice to prevent ice- overburden pressure from causing borehole closure. Looking over the properties of the low-temperature drilling fluids for oil and gas well drilling confirms that they are not suitable for deep drilling in central Antarctica. Only special fluids, or mixture of fluids, can satisfy very strict criteria for deep drilling in ice. The main properties of existing and potential drilling fluids were described in the report of Talalay and Gundestrup, 1999, concluding that all recent borehole fluids cannot be qualified as intelligent choices because of the safety, environmental, and other technological standpoints. Several new drilling fluids have been proposed in the past several years. The present report aims to update the state of drilling-fluid research with newly available data, and to point out new directions of drilling fluid research.