Influence of eccentricity on deflected mode of cement ring in bore

The design of a well is determined by the amount, diameter and depth of casing running, borehole diameter for each of the casing, cementing casing intervals. Casing annular space is filled with a special cement slurry that eventually harden, to ensure a hermetic and strong attachment. The walls of the wells are stable. The high quality of cementing protects flow of fluids from one seam or seams in others. In real well annular space is noticeably different from the configuration of its space between two coaxial cylinders. It is usually eccentrically located in the well. There are sections of the restrictions and extensions along the annular space. In this paper, the authors consider the solution of the eccentric ring under internal and external pressure. The dependences of the stresses, strains and displacements in the eccentric ring are demonstrated. A comparative analysis of the stress-strain state of the eccentric and concentric rings in the case of cement stone in the well is given. An example of distribution of rotational, radial and tangential stresses in the radial and circumferential directions in different sections of the eccentric cement annulus in a well operation is described. The estimation of the influence of eccentricity on the stress-strain state of the cement ring in a borehole is given.