In situ conversion of heavy hydrocarbons to catalytic gas

Abstract

A method of producing natural gas from a heavy hydrocarbon-containing subterranean formation includes: placing a catalyst having at least one transition metal into the formation, injecting an anoxic stimulation gas into the formation, and collecting the natural gas generated in the formation. The method may be performed outside the context of a subterranean formation under controlled conditions. Thus, a method of producing natural gas from bitumen includes: providing an anoxic mixture of heavy hydrocarbons and a catalyst having at least one transition metal, adding an anoxic stimulation gas to the mixture, and heating the mixture in the presence of the stimulation gas.

1 . A method of producing natural gas from a heavy hydrocarbon-containing subterranean formation comprising:
 placing a catalyst comprising at least one transition metal into the formation;   injecting an anoxic stimulation gas into the formation, wherein said stimulation gas is not hydrogen; and   collecting the natural gas generated in the formation.   
     
     
         2 . The method of  claim 1 , wherein the catalyst is provided from an active source rock. 
     
     
         3 . The method of  claim 1 , wherein the catalyst is provided on a proppant. 
     
     
         4 . The method of  claim 1 , wherein at least one transition metal is selected from the group consisting of a zero-valent transition metal, a low-valent transition metal, alloys, and mixtures thereof. 
     
     
         5 . The method of  claim 4 , wherein the at least one transition metal is selected from the group consisting of molybdenum, nickel, cobalt, iron, copper, palladium, platinum, rhodium, ruthenium, tungsten, osmium, rhenium, and iridium. 
     
     
         6 . The method of  claim 1 , wherein the stimulation gas is at least one selected from the group consisting of natural gas, natural gas depleted of methane, carbon dioxide, helium, argon, and nitrogen. 
     
     
         7 . A method of producing natural gas from heavy hydrocarbons comprising:
 providing a mixture comprising:
 heavy hydrocarbons; and 
 a catalyst comprising at least one transition metal; 
   adding an anoxic stimulation gas to the mixture;
 wherein the stimulation gas is not hydrogen; and 
   heating the mixture in the presence of the stimulation gas.   
     
     
         8 . The method of  claim 7 , wherein the catalyst is provided from an active source rock. 
     
     
         9 . The method of  claim 7 , wherein the at least one transition metal is selected from the group consisting of a zero-valent transition metal, a low-valent transition metal, alloys, and mixtures thereof. 
     
     
         10 . The method of  claim 9 , wherein the at least one transition metal is selected from the group consisting of molybdenum, nickel, cobalt, iron, copper, palladium, platinum, rhodium, ruthenium, tungsten, osmium, rhenium, and iridium. 
     
     
         11 . The method of  claim 7 , wherein the catalyst further comprises salts of at least one main group element selected from the group consisting of sulfur, phosphorus, arsenic, and antimony. 
     
     
         12 . The method of  claim 7 , wherein the anoxic stimulation gas is at least one selected from the group consisting of natural gas, natural gas depleted of methane, carbon dioxide, helium, argon, and nitrogen. 
     
     
         13 . The method of  claim 7 , wherein heating is carried out in a range from about 25° C. to about 250° C. 
     
     
         14 . The method of  claim 13 , wherein heating is carried out in a range from about 100° C. to about 200° C. 
     
     
         15 . A method of forming natural gas comprising:
 providing an anoxic mixture comprising:
 heavy hydrocarbons; and 
 a catalyst comprising at least one transition metal; 
   adding an anoxic stimulation gas to the mixture;
 wherein the stimulation gas is not hydrogen; and 
   heating the mixture in the presence of said stimulation gas.   
     
     
         16 . The method of  claim 15 , wherein the catalyst is provided from an active source rock. 
     
     
         17 . The method of  claim 15 , wherein the at least one transition metal is selected from the group consisting of a zero-valent transition metal, a low-valent transition metal, alloys, and mixtures thereof. 
     
     
         18 . The method of  claim 17 , wherein the at least one transition metal is selected from the group consisting of molybdenum, nickel, cobalt, iron, copper, palladium, platinum, rhodium, ruthenium, tungsten, osmium, and iridium. 
     
     
         19 . The method of  claim 15 , wherein the anoxic stimulation gas is at least one selected from the group consisting of natural gas, natural gas depleted of methane, carbon dioxide, helium, argon, and nitrogen. 
     
     
         20 . The method of  claim 15 , wherein heating is carried out in a range from about 25° C. to about 350° C. 
     
     
         21 . A method of stimulating natural gas production in a heavy hydrocarbon-containing subterranean formation comprising:
 fracturing the formation in a substantially oxidant free environment; and   adding an anoxic stimulation gas to the fractured formation.   
     
     
         22 . The method of  claim 21  further comprising withdrawing gases generated by the addition of the anoxic stimulation gas.