A method and system for determining a momentary boil-off rate for a storage tank for a natural gas in liquid phase and gas phase. A mass flow from the gas phase of the natural gas at an discharge pipeline of the storage tank and a mass flow into the liquid phase of the natural gas at an loading/discharge pipeline of the storage tank is determined. A volume, a temperature and a pressure of the gas phase of the natural gas is measured. A dynamical model is applied to the determined values to determine the momentary boil-off rate.

This publication relates to a shallow water terminal, preferably for storing and loading or unloading hydrocarbons, such as LNG, oil or gas. The base structure comprises a floatable, and removable seabed substructure (10) intended to be supported by a seabed (30), the seabed substructure (10) comprising a base structure (11) provided preferably with an upwards extending wall structure (22), arranged along at least a part of the periphery of the base structure (11), the base structure (10) preferably also being provided with an opening (23) in the wall structure (22) for allowing the floatable module to be berthed in and supported by the seabed substructure (10). The base structure (10) is provided with strong points (24) configured to receive the ends of preinstalled vertical piles (14) for at least temporary support of the base structure (11) during a piling operation for permanent piling of the base structure (10) to the sea bed (30). The publication also relates to a method for piling a base structure on or above a seabed (30).

A method for installing a subsea structure at a target installation site in an underwater location is disclosed. The method includes connecting at least one mooring line and at least one leading line to the structure, and towing the structure via the leading line from a deployment position to the target installation site, such that the structure moves both vertically and horizontally between the deployment position and the target installation site. The mooring line is anchored, e.g. to an anchoring device on the seabed, and can incorporate a ballast to apply a sinking force to the structure in proportion to the length of unsupported line. The mooring line and the leading line can together stabilise the structure as it descends to the installation site. The non-vertical installation allows accurate structure placement, e.g. in crowded fields, with less sensitivity to tidal or current forces.

A water-borne carrier for transporting liquefied natural gas (LNG) and liquefied nitrogen (LIN). A plurality of dual-purpose cryogenic storage tanks are arranged along a length of the ship. The plurality of dual-purpose cryogenic storage tanks may contain LNG or LIN. A LNG-only cryogenic storage tank may be arranged along the length of the ship. The LNG-only cryogenic storage tank contains only LNG.

An apparatus, system and method for capture, utilization and sendout of latent heat in boil off gas (BOG) onboard a cryogenic storage vessel is described. A liquefied gas vessel comprises a cryogenic cargo tank onboard a liquefied gas vessel, the cargo tank comprising a liquefied gas and a BOG, a latent heat exchanger fluidly coupled to a stream of the liquefied gas and a stream of the BOG, wherein the latent heat exchanger transfers a heat between the BOG stream and the liquefied gas stream to produce a condensed BOG, means for combining the condensed BOG and the liquefied gas stream to obtain a combined stream, the means for combining the condensed BOG and the liquefied gas stream fluidly coupled to the latent heat exchanger, and a liquefied gas regasifier onboard the vessel and fluidly coupled to the combined stream, wherein the liquefied gas regasifier regasifies the combined stream.

An apparatus, system and method for capture, utilization and sendout of latent heat in boil off gas (BOG) onboard a cryogenic storage vessel is described. A liquefied gas vessel comprises a cryogenic cargo tank onboard a liquefied gas vessel, the cargo tank comprising a liquefied gas and a BOG, a latent heat exchanger fluidly coupled to a stream of the liquefied gas and a stream of the BOG, wherein the latent heat exchanger transfers a heat between the BOG stream and the liquefied gas stream to produce a condensed BOG, means for combining the condensed BOG and the liquefied gas stream to obtain a combined stream, the means for combining the condensed BOG and the liquefied gas stream fluidly coupled to the latent heat exchanger, and a liquefied gas regasifier onboard the vessel and fluidly coupled to the combined stream, wherein the liquefied gas regasifier regasifies the combined stream.

The invention relates to a submersible system (1) comprising at least a first frame structure (2) for horizontal storage of tanks (3) with a positive buoyancy in water therein, wherein the first frame structure (1) has a negative buoyancy in water and comprises at least two storage positions (4) for supporting at least two tanks (3), wherein the storage positions (4) are arranged side by side in one level and each storage position comprises at least one cradle (4) for supporting a tank (3) from below, and wherein the system (1) comprises a fastening device (6,11) having a first and a second state, wherein: i. when in the first state, the fastening device (6,11) is configured to permit positioning of a tank (3) from above into the at least one cradle (4) and; ii. when in the second state, the fastening device (6,11) is configured to secure a tank (3) positioned in the at least one cradle (4) in a radial direction of the tank (3) preventing movement of the tank (3) in a vertical upward direction; and wherein a total buoyancy of the system (1) when submerged in water, when tanks (3) are positioned in each of the storage positions, is negative. The invention also relates to an associated method of storing tanks on a seabed using the submersible system (1).

The present invention relates to an anchor structure able to actively cope with hull deformation, and to a liquid natural gas storage tank and a production method for a liquid natural gas storage tank comprising the anchor structure. According to one embodiment of the present invention, an anchor structure is provided wherein an anchor structure, for linking a sealing wall and an inner wall of a liquid natural gas storage tank, comprises: an anchor member adapted such that a joining part, which is joined to the sealing wall, can slide horizontally; and a thermally insulating material formed around the anchor member.

An apparatus, system and method for capture, utilization and sendout of latent heat in boil off gas (BOG) onboard a cryogenic storage vessel is described. A liquefied gas vessel comprises a cryogenic cargo tank onboard a liquefied gas vessel, the cargo tank comprising a liquefied gas and a BOG, a latent heat exchanger fluidly coupled to a stream of the liquefied gas and a stream of the BOG, wherein the latent heat exchanger transfers a heat between the BOG stream and the liquefied gas stream to produce a condensed BOG, means for combining the condensed BOG and the liquefied gas stream to obtain a combined stream, the means for combining the condensed BOG and the liquefied gas stream fluidly coupled to the latent heat exchanger, and a liquefied gas regasifier onboard the vessel and fluidly coupled to the combined stream, wherein the liquefied gas regasifier regasifies the combined stream.

Disclosed is an apparatus, system, and method, by which a gaseous chemical, e.g., hydrogen gas, can be retrieved by, stored within, and transported by, a low-cost autonomous vessel. The vessel is deployed, and operates, within a body of water. A submerged portion of the vessel is subjected to an ambient hydrostatic pressure that is used to compress the stored gases. A spar buoy that floats adjacent to a surface of the body of water regulates and stabilizes a depth of the submerged portion. A single pressure-tolerant chamber within the submerged portion is used to acquire gas from a gas provider and to equilibrate the pressure of the gas so acquired. The pressure-equilibrated and/or pressure-balanced gas is then drawn into a first gas storage tank through a venting of an approximately equal volume of another gas, e.g., air, from a second gas storage tank, resulting in a gas transfer at an approximately constant pressure. The processing and storage of acquired gases at pressures approximately equal to the ambient hydrostatic pressures permits the use of thin-walled tanks, and makes possible a low-cost gas acquisition, storage, and transportation, vessel.