STRESS STATE COLUMNS OF TUBING STRING DURING OPERATION PULSED DOWNHOLE DEVICE

Abstract

When treating the bottomhole zone, the working fluid is supplied to the bottom unevenly due to the fact that the units are equipped with piston pumps. The changing amplitude of the liquid pressure is triggered in the pulsed downhole device. As a result, longitudinal oscillations are created in the tubing string. As the oscillations of the liquid propagate, their amplitude decreases. For these conditions, this is due to dissipative processes, which are called viscosity and thermal conductivity of the medium, the influence of the walls, and also scattering by inhomogeneities. We obtained expressions for determining the forced dynamic displacements and tensile stresses in each section of the tubing string, on which graphical dependences are plotted. As a result of the analysis of these curves, it was found that the usage of pulsed downhole device with a larger area of resistance to the flow of a liquid jet reduces the reliability of the tubing string, and it depends directly on both the design features of the device and the flow rate of fluid pumped into the formation. We also revealed that the reliability of the tubing string is increased by 1,8 times when using a packer for the equipment of the bottomhole of the treated well.