Hutyi A. Dynamic processes in drilling units during the release of the grab¬bed column of pipes

The dissertation is devoted to the increase of the efficiency of the release of a drill or casing pipe drilled in a well bore by justifying the rational modes of operation of drilling units and the parameters of impact devices on the basis of the improvement of mathematical models of dynamic processes in the mechanical system. A mathematical model and algorithm of calculation of dynamic processes that arise in a drilling rig and an unblocked part of a picked column of pipes with the consideration of the joint functioning of the actuating system and the impact mechanism, as well as the mathematical model of dynamic processes that arise in the locked part of the column due to the application static and dynamic pulsed loads. In the latter case, the multicomponent friction that occurs in the material and in the connections of the pipe column, as well as in the zones of direct contact of the column with the well wall and on the surfaces of the interaction of the drill bit column is taken into account. The influence of operational parameters of the drilling unit and the parameters of the impact device for the release of the picked column of the pipes on the dynamic forces in the column, the wire rope, and the drill tower are investigated.