A modeling of the inertia properties of a drill string section as a continual bent rotating rod

Abstract

The article considers the problem of determining the moment of inertia of the bent rotating section of the drill string. The tasks of such a plan are of paramount importance for the dynamic analysis of drill strings in rotary and rotaryturbine drilling methods. Presented are the exact and approximate analytical dependences for determining the moment of inertia of the bent section of the drill string, depending on the geometric parameters of its deflection. Given the scientific and practical interest in the use of pipes made of non-traditional materials, the moments of inertia for bent sections of steel, titanium, aluminum and fiberglass drill pipes are calculated. The nature of the change in the moment of inertia of sections of drill pipes of different diameters depending on the length of the half-wave and the magnitude of the maximum deflection is established. Keywords: drill string; rod; moment of inertia; deflection boom; deflection half-wave length.