SEPARATING DEVICE

摘要

The invention comprises a sealing body (15)-separatingseparating device) which can be used to separate fluids in risers used in offshore oil production from drilling vessels at the sea surface. The invention is characterized in that the sealing body (15) can be placed in position above the wellhead (13) using several appropriate methods and, in an especially preferred application, by utilizing an installation tool (27) which is not sealing against the inner wall of the riser and which contains a suitable positioning means (28), and that the body (15) which forms a seal against the inner wall of the riser separates fluids during the replacement of drilling fluid with water and of water with drilling fluid. The body (15) can be displaced using hydraulic force upwards in the longitudinal direction of the riser in that fluid is pumped at a relatively high pressure down the externally located smaller pipes (9, 10, 11) of the riser. The body can be used whilst the drilling vessel (1) heaves relative to the seabed (3), and it is independent of the drilling vessel's drawers for the drill string (21) while the fluid is being replaced.