Hydraulic fracturing methods and systems using gas mixture

Abstract

Systems and methods for fracturing in subterranean formations using treatment fluids that comprise a mixture of natural gas and other gases are provided. In some embodiments, the methods comprise: providing a fracturing fluid comprising a liquid base fluid and a gaseous component comprising natural gas and at least one unreactive gas; and introducing the fracturing fluid into a subterranean formation at or above a pressure sufficient to create or enhance one or more fractures in at least a portion of the subterranean formation.

What is claimed is: 
     
         1 . A method comprising:
 providing a fracturing fluid comprising a liquid base fluid and a gaseous component comprising natural gas and at least one unreactive gas; and   introducing the fracturing fluid into a subterranean formation at or above a pressure sufficient to create or enhance one or more fractures in at least a portion of the subterranean formation.   
     
     
         2 . The method of  claim 1  wherein the unreactive gas comprises at least one gas selected from the group consisting of: nitrogen (N 2 ), carbon dioxide (CO 2 ), argon (Ar 2 ), helium (He 2 ), and any combination thereof. 
     
     
         3 . The method of  claim 1  further comprising: vaporizing liquefied natural gas (LNG) to form the natural gas. 
     
     
         4 . The method of  claim 1  wherein the natural gas is provided as compressed natural gas (CNG). 
     
     
         5 . The method of  claim 1  wherein the unreactive gas is present in an amount of from about 0.01% to about 25% by total volume of the gaseous component. 
     
     
         6 . The method of  claim 1  wherein the unreactive gas is present in an amount of from about 0.01% to about 5% by total volume of the gaseous component. 
     
     
         7 . The method of  claim 1  further comprising: flowing at least a portion of the gaseous component comprising the unreactive gas out of the subterranean formation to a pipeline having at least one end disposed proximate to a well bore penetrating the subterranean formation. 
     
     
         8 . A method comprising:
 providing a liquid base fluid;   providing gaseous natural gas;   providing at least one gaseous unreactive gas;   mixing the liquid base fluid, the natural gas, and the at least one unreactive gas to form a fracturing fluid; and   introducing the fracturing fluid into a subterranean formation at or above a pressure sufficient to create or enhance one or more fractures in at least a portion of the subterranean formation.   
     
     
         9 . The method of  claim 8  wherein the at least one unreactive gas is provided in a first gaseous stream and the natural gas is provided in a second gaseous stream that is different from the first gaseous stream. 
     
     
         10 . The method of  claim 9  wherein
 the method further comprises mixing the first gaseous stream and the second gaseous stream to form a mixed gaseous stream, and 
 the step of mixing the liquid base fluid, the natural gas, and the at least one unreactive gas comprises mixing a liquid stream comprising the liquid base fluid with the mixed gaseous stream to form the fracturing fluid. 
 
     
     
         11 . The method of  claim 9  wherein the step of mixing the liquid base fluid, the natural gas, and the at least one unreactive gas comprises mixing a liquid stream comprising the liquid base fluid with the first gaseous stream and the second gaseous stream to form the fracturing fluid. 
     
     
         12 . The method of  claim 8  wherein providing gaseous natural gas comprises vaporizing liquefied natural gas (LNG) to form the gaseous natural gas. 
     
     
         13 . The method of  claim 8  wherein the unreactive gas is present in the fracturing fluid in an amount of from about 0.01% to about 5% by total volume of a gaseous component consisting of the natural gas and the unreactive gas. 
     
     
         14 . The method of  claim 8  wherein the unreactive gas is present in the fracturing fluid in an amount of from about 0.01% to about 25% by total volume of a gaseous component consisting of the natural gas and the unreactive gas. 
     
     
         15 . The method of  claim 8  further comprising:
 providing a proppant material; and 
 mixing the proppant material with the liquid base fluid prior to mixing the liquid base fluid with the natural gas and the at least one unreactive gas. 
 
     
     
         16 . The method of  claim 8  further comprising: flowing at least a portion of the gaseous component comprising the unreactive gas out of the subterranean formation to a pipeline having at least one end disposed proximate to a well bore penetrating the subterranean formation. 
     
     
         17 . A system comprising:
 a liquid base fluid source;   a liquid base fluid pump fluidly coupled to the liquid base fluid source for pressurizing a liquid base fluid to at least a pressure sufficient to create or enhance one or more fractures in at least a portion of a subterranean formation;   a natural gas source;   a natural gas pump fluidly coupled to the natural gas source;   an unreactive gas source; and   a mixer for mixing the liquid base fluid, gaseous natural gas, and gaseous unreactive gas to form a fracturing fluid mixture for injection into a wellhead at a well site comprising a well bore penetrating at least the portion of the subterranean formation, the mixer having at least a first inlet fluidly coupled to the liquid base fluid pump, a second inlet fluidly coupled to the natural gas pump, a third inlet fluidly coupled to the unreactive gas source, and an outlet fluidly coupled to the wellhead.   
     
     
         18 . The system of  claim 17  wherein the natural gas source comprises at least one LNG tank, the natural gas pump comprises a high pressure natural gas pump, and the system further comprises a heater component fluidically coupled to an outlet of the high pressure natural gas pump. 
     
     
         19 . The system of  claim 17  further comprising at least one controller communicatively connected to one or more of the liquid base fluid pump, the natural gas pump, the mixer, and/or one or more valves fluidically connected to one or more of the liquid base fluid source, the natural gas source, and the unreactive gas source. 
     
     
         20 . The system of  claim 17  wherein the system does not comprise a flare in fluid communication with the wellhead.