Offshore petroleum installation piping - incorporating bundle connecting sea-bed base to semi-submersible tank and pipe connecting tank to discharge

摘要

A pipe system for collecting petroleum products from a base on the sea bed incorporates a semi-submersible cylindrical tank with an upper part of smaller section, a bundle of flexible pipes and a separate flexible pipe. The tank is submerged below the surface of the sea. The upper part emerges above the surface and provides a mooring for a ship. The bundle of flexible pipes extends between the base and the tank and is maintained in tension by the tank. The separate flexible pipe is not in tension and connects the body of the tank to a point above the surface at which the petroleum is to be delivered. The invention improves the system described in the parent patent, in providing the separate flexible pipe. The pipe can have the same structure as those between the tank and the base and can comprise superposed tubular layers of steel wires wound spirally with a plastic inner sheath.