Patent ID: 8820412
Filing Date: 2014-09-02
Classification: E21B,F16L

Abstract:
1. A method for circulating fluid within the annulus of a flexible pipe riser in an offshore hydrocarbon production facility, comprising: pumping a liquid into an inlet port in a topsides riser end fitting in fluid communication with a plurality of tubes within at least one tape layer free of metal wires within an annulus of a flexible pipe riser wherein each of the plurality of tubes has at least one opening within the annulus, the flexible pipe riser having one end terminating at the topsides riser end fitting in fluid communication with the plurality of tubes within the at least one tape layer and another end terminating at a subsea riser end fitting; and discharging the liquid from the openings of the plurality of tubes within at least one tape layer into the annulus such that the liquid flows in the annulus and returns to the topsides riser end fitting in a closed loop.