Post-expansion tube response under mechanical and hydraulic expansion - A comparative study

This paper presents a mathematical model of post-expansion tube response under mechanical expansion. The stress, pressure, and displacement waves propagating through the tube-fluid system and their effect on the tube response are studied. The model takes into account coupling between the solid tube and surrounding fluid at the borehole/ expanded tube annulus, as well as the damping effect on tube structural response. The paper also conducts a comparative study aiming at studying the post-expansion tubular fluid response and identifying the different features between hydraulic and mechanical solid tube expansion. The results showed that the mechanical expansion is less harmful to the tube structural integrity. Unlike the hydraulic expansion, which resulted in local stress buildup along the tube, the mechanical expansion was characterized by low equivalent stress throughout its length and a smooth dying out response.