Abstract: There is disclosed a variety of arrangements for laying of rigid pipe from reeled storage and/or on-board welding fabrication. Thirteen independent aspects of the invention are identified. In one particular arrangement (FIGS. 3a-3b), a tilting lay tower (106) having two travelling clamps (210, 220) is provided centrally on a pipelay vessel with a radius control arch (140) pivotable to receive rigid pipe from either port or starboard lay paths. A vertical axis reel or carousel (104) is provided, within an arrangement of curved take-off arms (130, 134) and a large radius curved wall (128). By these means, pipe can be loaded onto the carousel either clockwise or anti-clockwise, and can be supplied to the lay tower via the port or starboard lay path. Continuous rigid product fabricated by a selection of welding lines (112, 114, 116) at the port side can be guided around the large radius wall either for reeling onto the carousel or for direct feeding to the lay tower.

Abstract: There is disclosed a variety of arrangements for laying of rigid pipe from reeled storage and/or on-board welding fabrication. Thirteen independent aspects of the invention are identified. In one particular arrangement (FIGS. 3a-3b), a tilting lay tower (106) having two travelling clamps (210, 220) is provided centrally on a pipelay vessel with a radius control arch (140) pivotable to receive rigid pipe from either port or starboard lay paths. A vertical axis reel or carousel (104) is provided, within an arrangement of curved take-off arms (130, 134) and a large radius curved wall (128). By these means, pipe can be loaded onto the carousel either clockwise or anti-clockwise, and can be supplied to the lay tower via the port or starboard lay path. Continuous rigid product fabricated by a selection of welding lines (112, 114, 116) at the port side can be guided around the large radius wall either for reeling onto the carousel or for direct feeding to the lay tower.

Abstract: Hydrocarbon liquids are transported from a subsea welihead to an above-surface hydrocarbon processing facility along a pipe-in-pipe flowline. The flowline is a pipe placed coaxially within an outer carrier pipe and the annulus between the pipes is filled with thermally insulating material. The hydrocarbon liquids have their temperature maintained above solidification/precipitation temperature by heat from an active heating system. Hot liquid, preferably hot water, is passed along the annulus, either along a single pipe or multiple pipes installed in the insulation-filled annulus, or along an inner annulus formed by a water pipe added concentrically around the hydrocarbon-transporting inner pipe, inside the outer insulation-filled annulus. The water or other suitable liquid can be heated in a heater at or adjacent the subsea wellhead, or by a water heater in the above-surface hydrocarbon processing facility.

Abstract: Hydrocarbon liquids are transported from a subsea wellhead to an above-surface hydrocarbon processing facility along a pipe-in-pipe flowline wherein the hydrocarbon-transporting pipe is placed coaxially within an outer carrier pipe and the annulus between the pipes is filled with thermally insulating material. The hydrocarbon liquids have their temperature maintained above solidification/precipitation temperature by heat from an active heating system in accordance with the invention. Hot liquid, preferably hot water, is passed along the annulus, either along a single pipe or multiple pipes installed in the insulation-filled annulus, or along an inner annulus formed by a water pipe added concentrically around the hydrocarbon-transporting inner pipe, inside the outer insulation-filled annulus.