Riser and well casing analysis during drift-off: a coupled solution in the time domain

Abstract One of the most serious incidents that can occur in offshore drilling and exploration is damage to well structure subsea components which result uncontrolled hydrocarbon release environment present a safety hazard rig personnel. Over decades, there have been substantial developments mathematical models algorithms used analyze stresses on related define operational integrity windows operations proceed safely where mechanical preserved. The purpose this work time-domain solution system equations model dynamic behavior riser casing strings, when connected for drilling/completion during event drift-off rig. combines using finite differences dynamics recursive method soil. It allows coupling between with describe station keeping capabilities are lost. use forward–backward finite-differences coupled does not require linearization forces acting making it an ideal methodology analysis while improving convergence. findings study help improve understanding impact watch circle limits riser/well integrity, whether these set based quasi-static drive-off/drift-off or fully dynamic. gain accuracy dynamics, interaction top drive-off/drift-off, evaluated, effects varying tension compressive loads string also analyzed. In particular, shown results representing drift-off/drive-off less conservative than approach. Another important finding substantial, indicates solving separately riser-casing approach provides reasonable computational effort. be evaluate wellhead fatigue life intervention. Finally, limitations discussed.