| 摘要 |
<p>Conventional riser assemblies for conveying fluids from undersea oil or gas deposits use flexible hoses. Such hoses are prohibitively expensive for use in deep water locations and are prone to failure. The invention provides an offshore oil or gas production system comprising a floating production vessel (53) and a riser assembly (50) extending between the vessel and a seabed well head (57). The riser assembly comprises at least one flexible steel riser (50) suspended, in catenary, from an outer edge (51) of a deck (52) of the floating production vessel and an anchor (54) located on the seabed (56) and spaced from the well head (57). A riser assembly comprising a plurality of flexible steel risers can be installed quickly by simultaneously laying a plurality of such risers from a reel mounted on a pipe laying vessel and simultaneously disconnected and lowered into a trench on the seabed if it becomes necessary to move the vessel.</p> |
