US 12,618,309 B1 · Methods for preventing corrosion in flexible pipe with passivating agents

Abstract

Disclosed are methods and apparatus for preventing corrosion within the annulus of a flexible pipe used in a riser in an offshore hydrocarbon production facility. Buffer fluid comprising a passivating agent is introduced into the annulus to form protective layers on metal surfaces within the annulus to resist corrosive materials from contacting the metal surfaces. The passivating agents may be one or more of a polyalphaolefin, a polybutene, or a polysiloxane. A corrosion inhibitor may be combined with the passivating agent in the buffer fluid. Pretreating of the metal surfaces within the annulus prior to introduction of the buffer fluid can be performed with a pretreating corrosion inhibitor.

Claims22

Dependent claims

A method for preventing or reducing corrosion in an offshore hydrocarbon production facility, comprising:

pumping a buffer fluid comprising one or more passivating agents into an inlet port in a topsides riser end fitting in fluid communication with a plurality of tubes within an annulus of a flexible pipe riser wherein each of the plurality of tubes comprises at least one opening within the annulus, the flexible pipe riser comprising one end terminating at the topsides riser end fitting in fluid communication with the plurality of tubes within the annulus and another end terminating at a subsea riser end fitting;
and
discharging the fluid from the openings of the plurality of tubes into the annulus such that the fluid flows in the annulus;
wherein the one or more passivating agents comprises one or more of a polyalphaolefin, a polybutene, or a polysiloxane.

1 more element

Dependencies are inferred from the claim text.

Methods for preventing corrosion in flexible pipe with passivating agents

Life of this patent

Methods for preventing corrosion in flexible pipe with passivating agents

Life of this patent

Abstract

Claims22