Use of underground reservoirs for re-gassification of LNG, storage of resulting gas and / or delivery to conventional gas distribution systems

Abstract

The present invention is a method for re-gassifying Liquefied Natural Gas (LNG) in a subterranean formation/cavity, storing the resulting gaseous hydrocarbon in the same or connected strata, then subsequent conventional production and delivery of the gas to end users. LNG is injected into a permeable subterranean reservoir through surface and wellbore equipment suitable for operations at cryogenic temperatures. The liquid hydrocarbon vaporizes in the permeable rock/cavity near the injection wellbore as it gains thermal energy from the surrounding strata. The resulting gas is held within the reservoir for subsequent production and/or immediately produced by producing wells in the same or contiguous formations. The invention eliminates the need for onshore LNG receiving/storage terminals.

I claim:  
     
         1 . A method of storing natural gas comprising liquefying natural gas to obtain liquefied natural gas (“LNG”), transporting the LNG to a location near a subterranean reservoir within a formation, off loading the LNG into the reservoir, and permitting the ambient heat of the formation to vaporize the LNG into the natural gas.  
     
     
         2 . The method of  claim 1  wherein the LNG is offloaded into the reservoir through at least one injection well in fluid communication with the reservoir.  
     
     
         3 . The method of  claim 1  wherein the gas is withdrawn from the reservoir through at least one production well in fluid communication with the reservoir.  
     
     
         4 . The method of  claim 1  wherein the gas reservoir has a flow capacity, with respect to gas, of at least about 1000 md-ft.  
     
     
         5 . The method of  claim 1  wherein the reservoir has a flow capacity, with respect to gas, of at least about 10,000 md-ft.  
     
     
         6 . The method of  claim 1  wherein the reservoir has a flow capacity, with respect to gas, of at least about 100,000 md-ft.  
     
     
         7 . The method of  claim 2  wherein the injection well is capable of receiving cryogenic fluids.  
     
     
         8 . The method of  claim 2  wherein the injection well is capable of injection rates of the LNG in the range of about 1,000 to about 100,000 barrels per day.  
     
     
         9 . A method of storing natural gas comprising liquefying the natural gas to obtain liquefied natural gas, (“LNG”), transporting the LNG to a location near a subterranean gas reservoir wherein the reservoir has a flow capacity of at least about 10,000 md-ft, offloading the LNG into the reservoir through at least one injection well capable of receiving cryogenic fluids and which is in fluid communication with the reservoir, permitting the ambient heat of the formation to vaporize the LNG back into the natural gas, and withdrawing the natural gas through at least production well in fluid communication with the reservoir.  
     
     
         10 . The method of  claim 9  wherein the reservoir has a flow capacity, with respect to gas, of at least about 100,000 md-ft.  
     
     
         11 . The method of  claim 9  wherein the injection well is capable of injection rates of at least about 10,000 to about 50,000 barrels of LNG per day.