Patent ID: 8490565
Filing Date: 2013-07-23
Classification: B63B,F17C

Abstract:
1. A method for receiving a dry gas from a pretreatment source, processing the dry gas into a liquefied natural gas, offloading the liquefied natural gas to a transport vessel with storage tanks, and transporting the liquefied natural gas to another location using the transport vessel, wherein the method comprises: a. mooring a floating liquefaction vessel to a seabed with a plurality of mooring lines extending below a sea level; b. using a connecting device connected to the floating liquefaction vessel to: c. receiving the dry gas from the pretreatment source onto the floating liquefaction vessel, wherein the dry gas comprises primarily methane with small amounts of ethane; d. cooling the received dry gas to a cryogenic temperature using a heat exchanger connected to a liquefaction train, forming the liquefied natural gas; e. transferring the liquefied natural gas from the floating liquefaction vessel to the transport vessel using an offload flexible conduit on the floating liquefaction vessel in fluid communication with a walkway offload flexible conduit on the telescoping walkway; f. transferring personnel and equipment within an enclosed walkway formed in the telescoping walkway between the floating liquefaction vessel and the transport vessel; g. returning hydrocarbon vapor from the transport vessel to the floating liquefaction vessel using a walkway vapor return flexible conduit connected to the telescoping walkway and in communication with a vapor return flexible conduit on the floating liquefaction vessel, and maintaining the hydrocarbon vapor at a cryogenic temperature, wherein the hydrocarbon vapor is formed during offloading of the liquefied natural gas from the floating liquefaction vessel to the transport vessel; h. using a transport vessel controller of the transport vessel to continuously monitor a member of the group consisting of: receipt of the liquefied natural gas, storage of the liquefied natural gas in the storage tanks, offloading of the liquefied natural gas from the storage tanks, and combinations thereof; i. dynamically positioning the transport vessel in proximity to the floating liquefaction vessel using computer instructions in the transport vessel controller and a member of the group consisting of: j. storing the liquefied natural gas in the storage tanks on the floating transport vessel at a cryogenic temperature; k. releasing the transport vessel from the connecting device and the floating liquefaction vessel; and l. using the transport vessel to transport the liquefied natural gas to another location.