| dc.description.abstract | Slotted liners are widely used in horizontal wells because of the abilities to ensure wellbore integrity and sand control. During installation and operations, the slotted liners have to be strong enough to hold axial loads and radial compression to prevent excessive buckling and deformation of slots.
In this work, past papers about casing/liner failure are reviewed, and a comprehensive FEM analysis of various slotted liner failure mechanisms, including axial compression, bending, and collapse is studied. Experiments are carried out to compare with simulation.
Experiments were designed to select the grades of materials, diameter/thickness of pipes, and slot pattern. For the base pipe, the maximum strain is associated with more uniform deformation. In contrast, the maximum distortion of the slotted liner is concentrated around the slots. As a result, the depletion limit needs to be reduced to avoid casing/liner failure.
Finite element models were developed to decide the slotted liner design under various load conditions. A 3D nonlinear finite element method (FEM) model was developed for simulating stress changes related to rock mechanics and depletion in the formation, including overburden, reservoir section and underburden to evaluate the effect of stress change on casing stability. Various lithology and rock failure theories can be considered in the model.
The study showed considerations for slotted liner design and analyzed how much material grades, casing/tubing dimension and slot patterns can be expected to evaluate the risk of slotted liner failure. The numerical and experimental results in this work can help engineers understand mechanisms of slotted liner failure and optimize the slotted liner design. A series of simulation steps can be followed to simulate deformation and failure mechanisms of many more complex downhole tools. | en |
