Finite Element Modelling of Casing in Gas Hydrate Bearing Sediments (SPE-113819)

摘要

Casing integrity in shallow marine sediments can be a challenge if natural gas hydrates are present in sediments. Elevated wellbore temperature during drilling of deeper sections of deep offshore wells can cause in situ gas hydrates to dissociate, thereby increasing pore pressure and altering the mechanical properties of the sediments. Gas hydrate can also dissociate during setting and/or cementing, causing gas release which could result in delaying completion of the wellbore due to the flow of gas around the casing (conductor pipe) or affecting the casing integrity by creating a void (channel) in the cement sheath leading to non-uniform stress loadings