To provide stability of oil wells against collapse the bore hole is lined by a steel shell. A recently developed technique in oil well drilling is the mono-diameter method. In this technique an under-sized steel pipe is lowered into the bore hole and then expanded to the required diameter. During drilling and exploitation of the well the steel lining is subjected to various internal and external pressures. No collapse should occur due to any of these loads.
For reliable estimation of both expansion forces and collapse loads accurate material properties are required. Due to the cyclic nature of the loads a simple tensile test is not sufficient.
The objective of this project is to design a set of experiments and corresponding equipment to characterize materials which are used for the pipes. These experiments should be relatively simple and robust. Preferably it should be possible to perform them on standard testing equipment with minor adaptions.
The following steps are foreseen to reach this goal.
Investigate nominal and critical environmental circumstances during down hole pipe expansion operations.
Review deformation modes applied to the pipe material during pipe expansion and collapse in different environments.
Investigate sensitivities of simulation results to the choice of the material model (e.g. isotropic vs kinematic) and material parameter values and identify the required accuracy of the plasticity model.
Design material tests by which the material parameters can be identified and can be determined to desired accuracy.
Deadline Application: 15-03-2016
Further details:
PDEng Project: Materials testing method for expanded pipes at University of Twente