Buoy for injecting fluid in a subterranean void and methods for connecting and disconnecting a fluid passage from a vessel to the buoy
AssigneeHorisont Energi AS
InventorsBjørgulf Haukelidsæter Eidesen, Ståle Brattebø
Life of this patent
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Abstract
A buoy accomplishes a fluid connection between a vessel on a water surface and a subsea template located on a seabed via at least one riser. A fluid is transported by the fluid connection from the vessel to the subsea template, and the fluid is injected from the subsea template (120) into a subterranean void via a drill hole. At least one valve in the buoy is controllable from an external site in response to commands so as to shut off the fluid connection from the vessel to the at least one riser.
Claims16
A buoy configured to accomplish a fluid connection, via at least one riser, from a vessel on a water surface to a subsea template located on a seabed, so as to enable transport of fluid from the vessel to the subsea template for injection of the fluid into a subterranean void via a drill hole from the subsea template to the subterranean void, the buoy comprising:
- at least one valve configured to allow or shut off a passage of fluid from the vessel to the at least one riser,
- wherein the buoy comprises a primary communication interface configured to:
- be connected to an external site positioned at a location being geographically separated from an offshore injection site containing the subsea template and from the vessel, and
- receive commands from the external site,
- wherein in response to the received commands, the buoy is configured to, by electrical operation, control the at least one valve to either allow or shut off the passage of fluid from the vessel to the at least one riser.
A method for connecting a passage for a fluid from a vessel on a water surface to a subsea template located on a seabed via a buoy and at least one riser between the buoy and the subsea template, which subsea template is configured to inject the fluid further into a subterranean void via a drill hole, the method comprising:
- connecting at least one output pipe in the vessel to a respective at least one swivel connector in the buoy;
- measuring at least one respective pressure level in each of the at least one riser;
- determining, based on the at least one respective pressure level in each of the at least one riser, a respective equalization pressure for each of the at least one riser;
- pressurizing each of the at least one output pipe in the vessel to said respective equalization pressure;
- and thereafter
- opening, by electrical operation, at least one valve in the buoy to each of the at least one riser in response to commands received from the external site positioned at the location being geographically separated from the offshore injection site containing the subsea template and from the vessel;
- and thereafter
- opening at least one valve in the subsea template to each of the at least one riser.
A method for disconnecting a passage for a fluid from a vessel on a water surface to a subsea template located on a seabed, which subsea template is configured to inject the fluid further into a subterranean void via a drill hole, the vessel being in fluid connection with the subsea template by means of a buoy and at least one riser, the method comprising:
- while the fluid is being passed from the vessel into the subterranean void, injecting at least one assisting liquid into each of the at least one riser;
- shutting off the passage of fluid from the vessel to the at least one riser by closing, by electrical operation, a respective at least one valve in the buoy in response to commands received from the external site positioned at the location being geographically separated from the offshore injection site containing the subsea template and from the vessel;
- measuring a pressure level in each of the at least one riser;
- continuing to inject the fluid into the subterranean void via the at least one riser until the pressure level in each of the at least one riser has reached an equalization level, and after that the pressure level in each of the at least one riser has reached the equalization level
- closing a respective at least one valve in the subsea template to each of the at least one riser.
Dependencies are inferred from the claim text.