| 摘要 |
<p>J-CONFIGURED OFFSHORE OIL PRODUCTION RISER A riser system having at least one riser with a J-shaped configuration for transporting hydrocarbon fluids from a subsea manifold or wellheads to a surface vessel. The riser has a horizontal section, an upright section, and a sag bend section interconnecting the horizontal and upright sections. The horizontal section is connected at one end to the subsea manifold and extends along and in frictional engagement with the seabed away from the manifold. The upright section has a vertical end part coupled to the surface vessel. The vessel can remain in position with dynamic thrusters or mooring lines, and the vessel remains on station applying horizontal pull to the riser while heading into the prevailing sea and as hydrocarbon fluids are transported from the manifold through the riser to the surface vessel. The horizontal pull on the riser due to the surface vessel is taken up by friction forces between the horizontal section of the riser and the seabed. The riser system can be comprised of a number of risers coupled together in a cluster. In this case, the manifold has a rotatable connector box provided with a number of bores for receiving the lower ends of respective risers.</p> |
