Gridzhuk Y. Development of scientific bases for the engineering of dynamic processes of pipe and rod columns at drilling and operation of wells

Dissertation is devoted to the decision of an important scientific and technical problem of engineering of dynamic processes of the pipe and rod columns which are subject to intensive fluctuations in the conditions of drilling and operation of oil and gas wells. A mathematical model for the study of the change in the inertia of the solution-filled bent sections of the drill string depending on the parameters of their deformation is developed. Theoretical and methodological principles for determining the kinetic energy and moment of inertia of the flywheels of the drill string, which indicate the feasibility of using drill pipes with less inertia to ensure its energy efficiency. Dependences for estimating the friction forces of the deformed section of the drill string to the well wall, when the point of contact along the helical trajectory, and the work of the axial load and torque to overcome them. Mathematical models have been developed to estimate the stress-strain state of a section of a pump-compressor pipe column and the durability of its elements on the basis of kinetic potential, which take into account kinematic parameters of transverse bending oscillations and geometric parameters of spatial deformation. Theoretical and methodological principles of estimating the load of the cross sections of the pump rod column, determining the coefficients of attenuation and dissipation of its oscillations with the establishment of conditions for resonance prevention have been developed.