Abstract: Telescoping riser arrangement forming part of a riser string (1) connecting a subsea well and a floating installation. The riser arrangement is adapted to be switched between a high pressure mode, in which an upper part of the riser assembly will move vertically with respect to the installation when the installation heaves, and a low pressure mode in which the upper part of the riser assembly will move vertically along with the installation when the installation heaves. In the low pressure mode, a low pressure inner sleeve (9) is adapted to reciprocate inside a high pressure outer sleeve (1a), the reciprocating heave path being above the position of the inner sleeve (9) in the high pressure mode. In the high pressure mode, the telescoping section of the low pressure inner sleeve (9) is enclosed within a high pressure compartment.

Abstract: A tension frame (2) for its application in a riser system for hydrocarbon exploration and production. The tension frame is (2) installed on a well control unit (5) atop at least one riser (9) in said riser system. The frame is adapted to receive a pressure control unit and hold it in line with the centre of the riser. The tension frame (2) houses at least two pre-installed pressure control equipment units (3, 4) of which one at a time is adapted to be hold at an active position, in which the unit is in line with the centre of the riser, and the other is adapted to be kept in a parked position within the frame.