A finite element model to predict axial forces with friction in tubing strings

Resumo

This work shows a one-dimensional finite element model to predict axial forces with friction in tubing strings subjected to operational loads in the production of oil and gas. These strings undergo different combinations of axial forces throughout their lifetime. Accurate prediction of these forces is essential to maintain the structural integrity of this fundamental component of the well barrier system. Frictional forces, which impact axial forces, occur due to the contact between the string and the casing, which happens when the tube buckles. In directional wells, the weight and trajectory of the tubing also generate frictional forces along the casing. Due to the variety of operational loads, a general solution to the friction problem requires a numerical approach. To achieve the proposed objective, the adopted modeling is verified through analytical solutions, investigating results regarding the axial forces and displacements experienced by the tubing in different operations. Mesh refinement studies and computational cost of the model are also discussed. Its observed a good concordance between numerical and analytical results, coupled with an acceptable computational cost. The main contribution of the work is the possibility of using numerical modeling for tubing, including friction, with good accuracy, low computational cost, and potential for real-time analysis.