Visualizing Well System Breakdown: Experimental and Numerical Analyses Available to Purchase

Leaky wells are expensive to plug, provide a potential pathway for subsurface fluid migration, and are difficult to study in the field. Because of the inherent cost and risk associated with researching well integrity at the field-scale, a novel approach is being developed to increase our understanding of cement failure within the well system. This paper presents the approach, which combines a scaled experimental technique with an analytic model to rapidly and repeatedly simulate conditions that lead to failure in the well system. The experimental approach consists of a loading apparatus that can apply confining loads and internal “casing” pressures independently to a scaled-down (<50 mm) model of a complete well system. The apparatus is contained in an industrial X-Ray CT scanner, which is capable of collecting 3D scans while loads are applied to the scaled well system. The ability to collect 2D radiographs, pressure data, and CT scans on the model well system during loading provides a unique and valuable means of performing destructive testing with non-invasive, in-situ imaging. For this study, the internal casing pressure was increased by 3.45 MPa (500 psi) increments until failure was observed in the form of radial cracks within the cement.