Application of rod mechanics fundamentals for analysis of stress-strain state of the tubing

Abstract

Розроблено метод аналізу напружено-деформованого стану колони насосно-компресорних труб, що знаходиться в просторово викривленому локальному перегині осі свердловини. Встановлено, що в таких ділянках свердловини істотно збільшується величина напружень згину, а зміна осьового зусилля, викликана зворотно-поступальним рухом штангової підвіски, може ініціювати виникнення циклічних згинальних моментів у насосно-компресорних трубах. Ключові слова: напружено-деформований стан, насосно-компресорна колона, локальний перегин осі свердловини.

Evaluation the Stress-Strain State of Pumping Equipment in the Curvilinear Sections of the Wells

“…The following coordinate systems are identified: 1) global coordinate system (GCS 1) -a reference system in which the coordinates of the well inclinometry points are set; 2) local coordinate system (LCS) -a reference system, in relation to which the analysis of the PU stress-strain state model is carried out; 3) global coordinate system of the working environment "AnSYS" (GCS 2) -a reference system, in relation to which a 3D model of the scientific equipment is created in the environment "AnSYS". As for analytical studies, according to the third version of the design scheme, the "Z" axis of the LCS passes through the points of the well at a depth of 1130 m and 1170 m. The beginning of the axis is located at a point at a depth of 1130 m, and the orientation of the "X" and "Y" axes is determined according to the technique given in [14].…”

“…According to the aforementioned methodology [14], the PU is modeled as a weighty long-length object of circular cross-section with a given estimated moment of inertia. According to the calculation scheme ( Fig.…”

“…Simulation using the finite element method to confirm the reliability of the results requires comparison with similar experimental or analytical studies [5,20]. Given the complexity of the experiment, it is proposed to use the results of studies using a previously tested methodology for comparison [14]. For research, the results of the inclinometry of the well interval are used and a number of simplifications are made.…”

“…Solution (1) -(5) is implemented by projecting on the axis of the moving coordinate system using the following system of boundary conditions u1ሺ0ሻ ൌ 0, u2ሺ0ሻ ൌ 0, u3ሺ0ሻ ൌ 0 ϑ1ሺ0ሻ ൌ 0, ϑ2ሺ0ሻ ൌ -α 0xz nሺ0ሻ, ϑ3ሺ0ሻ ൌ -α 0xy nሺ0ሻ Q1ሺ1ሻ ൌ P ሺ1ሻ 1, u2ሺ1ሻ ൌ 0, u3ሺ1ሻ ൌ 0 M1ሺ1ሻ ൌ 0, M2ሺ1ሻ ൌ 0, M3ሺ1ሻ ൌ 0 uiሺεሻ, Qiሺεሻ, Miሺεሻ -projections of the displacement vector, transverse force and bending moment on the axis of the moving coordinate system; i = 1, 2, 3. PU deflection in the vicinity of a given point of inclinometry is determined using the approach described in [14].…”

“…The contact with the walls of the well at certain points is likely. Taking in to account mentioned previously the coordinates of its elastic axis are given as [14].…”