A pipe between a seabed BOP and a floating drilling rig.

The section of pipework that joins a seabed wellhead to the Christmas tree. A pipe or assembly of pipes used to transfer produced fluids from the seabed to the surface facilities or to transfer injection fluids, control fluids, or lift gas from the surface facilities and the seabed.

Risers can be either rigid or flexible and are critical components of subsea installations.

A riser is the segment of pipe which connects vertically the facilities above the water to the subsea pipeline.