Development, model validation, and preliminary experimental verification of an FEA program for structural analysis of casing in casing for oil wells.

Abstract

Oil and gas wells rely upon long steel pipes, known as casing, that run down the depth of the well. During drilling, a section of pipe is cemented in place and another section of casing is run inside, repeating this process as necessary. This process is not 100% accurate, leading to eccentric configurations that increase the resulting stress state. A memory efficient parallelized in-house Finite Element Analysis (FEA) program based on classical elasticity theory is developed to analyze a 2D and 3D model of this pipe-in-pipe configuration. The program is compared to commercial software for verification of the mathematical application. A Monte Carlo setup is applied on top of the program to account for uncertainties in pipe eccentricity, material properties, and well geometries. Preliminary validation of this application is sought with comparison to laboratory cement-filled pipe and cube compression samples through strain measurements.