Unique chemical delivery method for stimulating production in oil and gas wells

Abstract

A method of treating a wellbore in a subterranean formation includes attaching a surface located inert gas generator to an annular space in a wellbore that comprises a tubular element. A heated inert gas is generated using the inert gas generator, wherein the inert gas comprises CO2 and nitrogen. The heated inert gas is placed from the inert gas generator into the annular space. The heated inert gas is circulated from the surface, down the annulus, and returns up through the tubular element back to the surface for a period of time. At least one well treatment chemical is combined with the heated inert gas to form a matrix injection gas, wherein the chemical is at least one of suspended in the heated inert gas as droplets, in a vapor state of the chemical, and combinations thereof. The matrix injection gas is delivered to the formation.

What is claimed is: 
     
         1 . A method of treating a wellbore in a subterranean formation comprising:
 attaching a surface located inert gas generator to an annular space in a wellbore comprising a tubular element, wherein a cylindrical wall surrounds the tubular element in a manner that an annular space is formed between the tubular element and the cylindrical wall in the wellbore;   generating a heated inert gas using the inert gas generator, wherein the inert gas comprises CO 2  and nitrogen;   placing the heated inert gas from the inert gas generator into the annular space;   circulating the heated inert gas from the surface, down the annulus, and returning up through the tubular element back to the surface for a period of time until the tubular element has been at least partially cleaned;   combining at least one well treatment chemical with the heated inert gas to form a matrix injection gas, wherein the at least one well treatment chemical is at least one of suspended in the heated inert gas as droplets, in a vapor state of the chemical, and combinations thereof; and   delivering the matrix injection gas to the formation.   
     
     
         2 . The method of  claim 1 , wherein the treating occurs in a substantially horizontal portion of the wellbore. 
     
     
         3 . The method of  claim 1 , further comprising after the circulating step, pressurizing the near wellbore formation by partially closing a wing valve on the return to the surface for an abbreviated period of time, releasing the built-up pressure until the near wellbore return is at least partially clean; and incrementing the time of shut-in in similar abbreviated time increments and rapidly releasing pressure until the formation break-in pressure and a permeable flow rate are established. 
     
     
         4 . The method of  claim 1 , wherein the well treatment chemicals are selected from the group consisting of aromatic solvents, acids, scale inhibitors, paraffin dispersants, oxygen scavengers, biocides, beneficial bacteria, nano-materials, foams and combinations thereof. 
     
     
         5 . The method of  claim 1 , further comprising adding the inert treatment gas after the matrix injection gas to chase the matrix injection gas and force the matrix injection gas further into the formation to widely disperse the chemicals and other products. 
     
     
         6 . The method of  claim 1 , wherein compressed air is run through the inert gas generator to convert the oxygen in the compressed air into CO 2 . 
     
     
         7 . The method of  claim 1 , further comprising a heat exchanger, wherein the heated inert gas is cooled in the heat exchanger before placing the heated inert gas into the annular space. 
     
     
         8 . The method of  claim 1 , wherein the at least one well treatment chemical is atomized before combining it with the heated inert gas to form the matrix injection gas. 
     
     
         9 . The method of  claim 1 , wherein the tubular element includes a downhole pump, the method further comprising circulating heated inert gas to liquefy paraffin in the tubular element, and lifting the paraffin to the surface for collection using the downhole pump. 
     
     
         10 . The method of  claim 1 , wherein the formation comprises porous rocks and the matrix injection gas is applied to the rock face in the pores as a thin film. 
     
     
         11 . The method of  claim 10 , wherein the thin film thickness is in the range of about 0.4 nm to about 80 nm. 
     
     
         12 . A well treatment apparatus comprising:
 an inert gas generator comprising:
 a compressor configured to deliver compressed air to a reactor; 
 a reactor configured to receive compressed air from the compressor and to configured to generate an inert gas from compressed air; 
 an atomizer configured to receive inert gas from the reactor and atomize well treatment chemicals; 
 a pump configured to deliver well treatment chemicals to the atomizer; and 
 a controller configured to operate at least one of the compressor, reactor, pump, and combinations thereof. 
   
     
     
         13 . The apparatus of  claim 12 , further comprising a heat exchanger in fluid communication with the reactor discharge and the atomizer. 
     
     
         14 . The apparatus of  claim 13 , further comprising a flue gas booster in fluid communication with the reactor discharge and the atomizer inlet. 
     
     
         15 . The apparatus of  claim 12 , wherein the atomizer comprises:
 a vessel including
 a pressure chamber; 
 an inert gas inlet; 
 a well treatment chemical inlet; 
 a manifold for distributing the well treatment chemicals; 
 nozzles along the manifold for atomizing the well treatment chemicals into the pressure chamber; and 
 an outlet for delivering the inert gas and atomized well treatment chemicals to the well. 
   
     
     
         16 . The apparatus of  claim 12 , wherein the reactor can receive an exhaust pipe that slides inside the reactor body, wherein the exhaust pipe is between reactor and the atomizer. 
     
     
         17 . The apparatus of  claim 12 , wherein the reactor comprises a cooling jacket surrounding a combustion chamber, wherein the cooling jacket contains coolant. 
     
     
         18 . The apparatus of  claim 12 , further comprising a propane vaporizer in fluid communication between a propane supply line and the reactor. 
     
     
         19 . The apparatus of  claim 17 , further comprising a propane vaporizer in fluid communication between a propane supply line and the reactor, wherein the propane vaporizer is configured to receive coolant from the reactor to vaporize propane and elevate its pressure. 
     
     
         20 . The apparatus of  claim 19 , wherein the coolant used to vaporize the propane is sent back to the reactor cooling jacket after it has passed through the propane vaporizer. 
     
     
         21 . The apparatus of  claim 16 , wherein the exhaust pipe is a heat exchanging exhaust pipe. 
     
     
         22 . A well treatment system comprising:
 a well treatment apparatus configured to:
 attach a surface located inert gas generator to an annular space in a wellbore comprising a tubular element, wherein a cylindrical wall surrounds the tubular element in a manner that an annular space is formed between the tubular element and the cylindrical wall in the wellbore; 
 generate a heated inert gas using the inert gas generator, wherein the inert gas comprises CO 2  and nitrogen; 
 place the heated inert gas from the inert gas generator into the annular space; 
 circulate the heated inert gas from the surface, down the annulus, and returning up through the tubular element back to the surface for a period of time until the tubular element has been at least partially cleaned; 
 combine at least one well treatment chemical with the heated inert gas to form a matrix injection gas, wherein the at least one well treatment chemical is at least one of suspended in the heated inert gas as droplets, in a vapor state of the chemical, and combinations thereof; and 
 deliver the matrix injection gas to the formation.