Controlled directional drilling of boreholes in glacial mass using carrying cable tool
The paper presents a method to drill boreholes and side holes following a predetermined path. It suggests methods developed to calculate the curvature radius of a hole drilled in ice using carrying cable drilling tools. Two theoretical methods are described, i.e. analytical and tabular analytical. Based on the results obtained with a designed mathematical model, equations were produced to define the spatial position of the drilling assembly at the borehole bottom. The tabular analytical method was used to obtain equations to calculate the curvature radius for the TBZS-152M drilling assembly (thermal tool for hole drilling using filler liquid) and the KEMS-132 drilling assembly (electromechanical core drilling tool). The discrepancy between the two calculation methods is 5%. A dedicated experimental drilling assembly was developed and tested.