A Simplified Method for Getting Tubing Deformation in Special Borehole Segment

Abstract

There exist flexures or even blind bends along some oil well boreholes. Inside working string at such segment usually has complicated deformation, and as a consequence how to study working string mechanical behavior becomes a bottleneck. In this paper, a deepwater well testing tubing string section near subsea wellhead is studied. Considering wellbore structure and tubing configurations, a third order differential equation of tubing lateral deformation is proposed, and for simplification the equation is reduced to second order. Numerical solution for third order equation, analytical solution for second order equation and results of simulated experiment are compared to verify the validity of simplified method. It shows that under large axial forces, compression or tension, results from simplified method are acceptable.