Levchuk K. Improving the Scientific Basis for Modelling the Dynamic Processes of the Liquidation of Stuck Drilling Tools

The dissertation is devoted to the improvement of technique and technology of mechanical methods of elimination the stuck tools, based on the use an energy accumulated in the drilling string due to impact or vibration. The dissertation has developed mathematical models for removing stuck by mechanical methods for different layouts of the drilling string in vertical and direction wells. The author proposes a new way of eliminating the stuck drilling pipes during drilling oil and gas wells by the method of frictional self-oscillations. The theoretical investigations obtained in the work became a basis for the development and introduction into practice and instructions for accident elimination which regulate for the use of the impact and vibration devices. The Borehole Straightener, the Roller-Bit Calibrator and two devices for removing sticking were developed. As a result, four patents were obtained.