Methods of fracturing with and processing lpg based treatment fluids

Abstract

A method of processing liquefied petroleum gas used in a treatment fluid previously injected into a hydrocarbon reservoir is disclosed, the method comprising: recovering at least a portion of the treatment fluid from the hydrocarbon reservoir to produce recovered treatment fluid; and separating liquefied petroleum gas in the form of a gas or liquid from the recovered treatment fluid using a separator. An apparatus for processing liquefied petroleum gas used in a treatment fluid previously injected into a hydrocarbon reservoir is also disclosed, the apparatus comprising: a separator; a recovery line for recovering treatment fluid from the hydrocarbon reservoir, the recovery line connected to supply recovered treatment fluid to the separator, the separator being to separate a liquefied petroleum gas portion in gas or liquid form from the recovered treatment fluid.

1 . A method of processing liquefied petroleum gas used in a treatment fluid previously injected into a hydrocarbon reservoir, the method comprising:
 recovering at least a portion of the treatment fluid from the hydrocarbon reservoir to produce recovered treatment fluid; and   separating liquefied petroleum gas in the form of a gas or liquid from the recovered treatment fluid using a separator.   
     
     
         2 . The method of  claim 1  in which separating further comprises separating an aqueous portion and a liquid hydrocarbon portion from the recovered treatment fluid. 
     
     
         3 . The method of  claim 1  in which separating further comprises separating a solids portion from the recovered treatment fluid. 
     
     
         4 . The method of  claim 1  in which separating further comprises vaporizing the liquefied petroleum gas in the recovered treatment fluid. 
     
     
         5 . The method of  claim 1  in which separating comprises separating a natural gas portion from the recovered treatment fluid. 
     
     
         6 . The method of  claim 5  in which separating further comprises a first stage comprising separating gases from the recovered treatment fluid, the gases comprising gaseous liquefied petroleum gas and natural gas, and a second stage comprising separating the gases into a liquefied petroleum gas portion and the natural gas portion. 
     
     
         7 . The method of  claim 6  in which the second stage further comprises liquefying the gaseous liquefied petroleum gas to separate the gases into the liquefied petroleum gas portion and the natural gas portion. 
     
     
         8 . The method of  claim 7  in which the liquefied petroleum gas portion and the natural gas portion are separated as a cooled stream of LPG and a cooled stream of natural gas, respectively, and in which liquefying further comprises cooling a stream of the gases by transferring heat from the stream of the gases to one or more of the cooled stream of LPG and the cooled stream of natural gas. 
     
     
         9 . The method of  claim 6  in which the separator is a five phase separator having as output liquefied petroleum gas in gas or liquid form, natural gas, an aqueous portion, a liquid hydrocarbon portion, and a solids portion. 
     
     
         10 . The method of  claim 6  further comprising supplying at least part of the natural gas portion to a sales line. 
     
     
         11 . The method of  claim 1  in which liquefied petroleum gas is separated from the recovered treatment fluid in the form of a liquid. 
     
     
         12 . The method of  claim 11  further comprising re-using the liquefied petroleum gas separated from the recovered treatment fluid as a well treatment fluid. 
     
     
         13 . An apparatus for processing liquefied petroleum gas used in a treatment fluid previously injected into a hydrocarbon reservoir, the apparatus comprising:
 a separator; and   a recovery line for recovering treatment fluid from the hydrocarbon reservoir, the recovery line connected to supply recovered treatment fluid to the separator, the separator being to separate a liquefied petroleum gas portion in gas or liquid form from the recovered treatment fluid.   
     
     
         14 . The apparatus of  claim 13  in which the separator is further connected to supply the liquefied petroleum gas separated from the recovered treatment fluid to at least one of a storage tank for storing liquefied petroleum gas, a flare, and a pipeline. 
     
     
         15 . The apparatus of  claim 13  further comprising a heater on the recovery line. 
     
     
         16 . The apparatus of  claim 13  in which the separator is adapted to separate a natural gas portion from the recovered treatment fluid. 
     
     
         17 . The apparatus of  claim 16  in which the separator further comprises:
 a first separator stage adapted to at least separate gases from the fluids, the gases comprising gaseous liquefied petroleum gas and natural gas; and 
 a second separator stage connected to receive the gases from the first separator stage and adapted to separate the gases into the liquefied petroleum gas portion and the natural gas portion. 
 
     
     
         18 . The apparatus of  claim 17  in which the second separator stage further comprises a liquefier connected to liquefy the gaseous liquefied petroleum gas from the gases. 
     
     
         19 . A method of treating a subterranean formation, the method comprising:
 introducing a hydrocarbon fracturing fluid into the subterranean formation, the hydrocarbon fracturing fluid comprising a gel of at least liquefied petroleum gas and a gelling agent;   subjecting the hydrocarbon fracturing fluid to pressures above the formation pressure; and   at least partially vaporizing the liquefied petroleum gas in order to break the gel.   
     
     
         20 . The method of  claim 19  in which at least partially vaporizing further comprises reducing the pressure the hydrocarbon fracturing fluid is subjected to. 
     
     
         21 . The method of  claim 19  in which the hydrocarbon fracturing fluid excludes a breaker.