# US 11,440,816 B2 · Sanitising seawater at subsea locations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,816 B2 - Document ID: US11440816B2 - Status: Granted - Kind: B2 - Application number: 16/455,415 - Filed: 2019-06-27 - Published: 2020-01-02 - Granted: 2022-09-13 - Earliest claimed: 2018-06-28 - Assignees: Subsea 7 Norway AS - Applicants: Subsea 7 (US) LLC - Inventors: Olivier Benjamin Labulle; Hans Anton Kros; Christopher Stephen Mancini - Web page: https://patentgrep.com/patent/US11440816B2 ## CPC - C02F 1/325: {Irradiation devices or lamp constructions} - C02F 2103/008: {Originating from marine vessels, ships and boats, e.g. bilge water or ballast water} - C02F 2103/08: Seawater, e.g. for desalination - C02F 2201/004: Seals, connections - C02F 2201/005: Valves - C02F 2201/3222: Units using UV-light emitting diodes [LED] - C02F 2201/328: Having flow diverters (baffles) - C02F 2303/04: Disinfection - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract A method of sanitising seawater at a subsea location comprises: exposing flow of seawater in a treatment reactor to UV radiation that sanitises the seawater without the addition of sanitising chemicals; and outputting the sanitised seawater from the reactor into a subsea structure such as a pipeline or a wellhead. The flow of seawater may be exposed to successive emitters of UV radiation such as pressure-compensated LEDs. The efficacy of sanitisation may be determined by: injecting a tracer fluid into the flow of seawater upstream of the reactor; and, downstream of the reactor, sensing transformation of the tracer fluid due to exposure of the tracer fluid to the UV radiation in the reactor. ## Claims ### Claim 1 A method of sanitising seawater at a subsea location, comprising: directing a flow of seawater along a serpentine path through a treatment reactor; imparting turbulence to the flow of seawater as it follows the serpentine path; exposing the flow of seawater in the treatment reactor to UV radiation that sanitises the seawater; and outputting the sanitised seawater from the treatment reactor into a subsea structure; wherein the serpentine path is defined by a plurality of baffles that that divide the treatment reactor into a series of interconnected chambers; each baffle of the plurality of baffles comprising a main body that extends inwardly from a sidewall of the treatment reactor and a projecting portion that extends outwardly from the main body in a direction towards an adjacent baffle in an L-shaped configuration. ### Claim 2 (depends on 1) The method of claim 1, where the subsea location is a seabed location. ### Claim 3 (depends on 1) The method of claim 1, wherein the subsea structure is selected from: a pipeline; a wellhead; a riser; a manifold; a jumper pipe; water injection equipment; a reservoir management system; reservoir testing equipment; and a coolant system. ### Claim 4 (depends on 1) The method of claim 1, comprising determining an efficacy of sanitisation of the seawater in the treatment reactor. ### Claim 5 (depends on 4) The method claim 4, comprising determining the efficacy of sanitisation by measuring the UV radiation within the treatment reactor. ### Claim 6 (depends on 4) The method of claim 4, comprising determining the efficacy of sanitisation by direct monitoring of an operational status of at least one emitter of the UV radiation. ### Claim 7 (depends on 4) The method of claim 4, comprising determining the efficacy of sanitisation by: injecting a tracer fluid into the flow of seawater upstream of the treatment reactor; and downstream of the treatment reactor, sensing transformation of the tracer fluid due to exposure of the tracer fluid to the UV radiation in the treatment reactor. ### Claim 8 (depends on 4) The method of claim 4, comprising, in response to the determined efficacy of sanitisation, adjusting a flow rate of the flow of seawater through the treatment reactor and/or adjusting an intensity of the UV radiation to which the flow of seawater is exposed in the treatment reactor. ### Claim 9 A device for sanitising seawater at a subsea location, comprising: a treatment reactor that contains at least one emitter of UV radiation for sanitising the seawater flowing along a serpentine path extending through the treatment reactor, the at least one emitter of UV radiation being a UV LED lamp that is modified to accommodate hydrostatic pressure; and an outlet downstream of the treatment reactor for outputting the sanitised seawater from the treatment reactor; wherein the treatment reactor comprises a plurality of baffles that divide the treatment reactor into a series on interconnected chambers through which the serpentine path extends, the plurality of baffles being configured to impart turbulence to a flow of seawater as it follows the serpentine path, each baffle of the plurality of baffles comprising a main body that extends inwardly from a side wall of the treatment reactor and a projecting portion that extends outwardly from the main body in a direction towards an adjacent baffle in an L-shaped configuration. ### Claim 10 (depends on 9) The device of claim 9, wherein the main body of each baffle extends inwardly in a direction transverse to the serpentine path. ### Claim 11 (depends on 9) The device of claim 9, wherein the treatment reactor contains at least one sensor, being a UV detector. ### Claim 12 (depends on 9) The device of claim 9, further comprising at least one tracer injection port upstream of the treatment reactor and at least one sensor downstream of the treatment reactor, the at least one sensor being a tracer detector to sense a composition, state or concentration of a tracer injected through the at least one tracer injection port. ### Claim 13 (depends on 11) The device of claim 11, further comprising a controller that is responsive to signals from the at least one sensor to vary intensity of UV radiation in the treatment reactor and/or to adjust flow rate of the seawater flowing along the serpentine path. ### Claim 14 (depends on 9) The device of claim 9, further comprising a flowmeter in the serpentine path. ### Claim 15 (depends on 9) The device of claim 9, further comprising a throttle valve in the serpentine path, arranged selectively to restrict or to close the serpentine path. ### Claim 16 (depends on 9) The device of claim 9, mounted on a skid or on a remotely operated vehicle (ROV). ### Claim 17 (depends on 9) The device of claim 9, configured to be powered by an on-board power supply and/or by a remotely operated vehicle (ROV). ### Claim 18 (depends on 9) The device of claim 9, in fluid communication with a subsea structure to receive the sanitised seawater from the device through the outlet.