Drilling riser

[2] When used in water depths greater than about 20 meters, the marine drilling riser has to be tensioned to maintain stability.

The level of tension required is related to the weight of the riser equipment, the buoyancy of the riser, the forces from waves and currents, the weight of the internal fluids, and an adequate allowance for equipment failures.

To reduce the amount of tension required to maintain stability of the riser, buoyancy modules, known in the industry as 'buoyancy cakes', are added to the riser joints to make them close to neutrally buoyant when submerged.

[3] Its purpose is to serve as a reference for designers, for those who select system components, and for those who use and maintain this equipment.

It relies on basic engineering principles and the accumulated experience of offshore operators, contractors, and manufacturers.