Patent ID: 8308518

Claim:
A floating relocatable method for receiving dry gas from a pretreatment source, processing the dry gas to form a liquefied natural gas at sea on a floating ballasted station, offloading the liquefied natural gas from the floating ballasted station to a moveable floating transport vessel for storage and transport to another location, the method comprising: a. receiving a pretreated dry gas from a pretreatment source, wherein the pretreated dry gas is primarily methane with small amounts of ethane; b. on the floating ballasted station: cooling the pretreated dry gas to a cryogenic temperature, forming a cooled dry gas; c. passing the cooled dry gas through a liquefaction train, forming a liquefied natural gas; d. flowing the liquefied natural gas from the floating ballasted station to the moveable floating transport vessel using a soft yoke, so that simultaneously: (i) offloading of the liquefied natural gas occurs using offload flexible conduits that adjust to accommodate floating ballasted station motion, moveable floating transport vessel motion, wave motion, current motion, and other weather motion without disengaging or leaking; (ii) a nominal distance is maintained between the moveable floating transport vessel and the floating ballasted station dynamically using at least one pivotable telescoping mooring arm of the soft yoke, wherein the at least one pivotable telescoping mooring arm has a jib nested within a pivotable boom accommodating for: floating ballasted station motion, moveable floating transport vessel motion, wave motion, current motion, and other weather motion without disengaging or leaking; (iii) the moveable floating transport vessel quick connects to the floating ballasted station and emergency disengages from the floating ballasted station in case of storms, rogue waves, or a fire using at least two connectors; personnel and gear are transported between the movable floating transport vessel and the floating ballasted station using an enclosed gangway formed by the jib and the boom; (v) continuous monitoring of offloading of the liquefied natural gas and return of a hydrocarbon vapor from the moveable floating transport vessel to the floating ballasted station using a yoke controller in communication with a vessel controller and a floating ballasted station controller; and (vi) the moveable floating transport vessel can be accommodated with a variety of stern configurations; e. storing the liquefied natural gas in liquefied natural gas storage tanks on the transport vessel at a cryogenic temperature; f. flowing the hydrocarbon vapor formed during offloading onto the transport vessel to the floating ballasted station using a vapor return flexible conduit, and maintaining a cryogenic temperature; and g. releasing the transport vessel from the floating ballasted station to transport the liquefied natural gas to another location.