Vortex Induced Vibration

Hydrodynamics of drilling riser buoyant joints

Offshore drilling is commonly performed with a top-tensioned drilling riser system. Operational uptime of the system is estimated through a global riser analysis, with input of hydrodynamic coefficients assumed by treating riser joints as circular cylinders. This is not accurate because the system consists mainly of buoyant riser joints with complex cross-sections. Buoyant joints have a generally circular shape but also have MUX recesses and stacking flats forming its outer profile. These surface features change its flow behaviour and hydrodynamic performance.