Abstract: Methods and arrangements for production of petroleum products from a subsea well. The methods comprise control of a downhole separator, supplying power fluid to a downhole turbine/pump hydraulic converter, performing pigging of a subsea manifold, providing gas lift and performing three phase downhole separation. Arrangement for performing the methods are also described.

Abstract: In order to avoid signal disturbances at communications through electric high power cables for supply of electric power to offshore installations, power cables that are galvanically insulated from each other are used. For example this may be done by supplying power at two single-phase pairs and use one conductor in every pair as signal conductor or by using a three-phase cable plus a single conductor.

Abstract: A tension member comprising a plurality of fiber filaments gathered into a plurality of strands. The filaments run close together, and a protective sheath is provided around the strands. Each strand is coated on the exterior thereof with a strand sheath of a material having a low friction coefficient, permitting the strands to move longitudinally in relation to one another and independently of each other.

Abstract: A pre-tensioning arrangement for inner and outer elongate concentric members includes a load member which is axially movable in an actuating direction relative to the inner member and has an outer surface which tapers in the actuating direction, a laterally expansible ring which is engaged by the load member in an inclined engagement zone during the actuating movement, and an engagement zone between the laterally expansible ring and the outer member, the engagement zones providing a mechanical advantage between the movement of the load member and movement of the outer member.