Minimizing fouling in steam assisted oil production

Abstract

Methods and systems generate steam for heavy oil recovery operations, wherein fouling is limited with the use of wire matrix turbulators in tubes with tendencies to foul.

What is claimed is: 
     
         1 . A steam generator system for oil production, comprising a once through steam generator (OTSG) having:
 an economizer section for pre-heating feedwater and fitted with a wire matrix turbulator;   a radiant section for converting said pre-heated feedwater to steam; and   an injection system for injecting steam into an oil reservoir, wherein the economizer section, radiant section and injection system are fluidly connected.   
     
     
         2 . The steam generator system of  claim 1 , wherein said wire matrix turbulator comprises a coiled wire, wherein subsequent coils are radially shifted around a central axis, and wherein all coils slant in a direction of fluid flow. 
     
     
         3 . The steam generator system of  claim 1 , wherein said wire matrix turbulator comprises stainless steel wire. 
     
     
         4 . The steam generator system of  claim 1 , wherein said wherein wire matrix turbulator comprises a polymer coated wire. 
     
     
         5 . The steam generator system of  claim 1 , wherein said wire matrix turbulator comprises a polymeric wire or mesh. 
     
     
         6 . The steam generator system of  claim 1 , wherein said radiant section also includes the wire matrix turbulator. 
     
     
         7 . The steam generator system of  claim 1 , further comprising a water and steam separator in fluid communication between the radiant section and the injection system for injecting separated steam into the oil reservoir. 
     
     
         8 . An improved method of producing steam for heavy oil production, the method comprising heating feedwater in a once-through steam generator (OTSG) sufficiently to make steam to inject into a wellbore and use in mobilizing heavy oil, the improvement comprising outfitting tubes in said OTSG with a turbulator and thus reducing fouling in said tubes as compared with the same OTSG lacking said turbulator. 
     
     
         9 . The method of  claim 8 , further comprising preheating feedwater in an economizer of the OTSG, then further heating said feedwater in the OTSG sufficiently to make the steam, wherein the tubes with the turbulator are disposed in said economizer. 
     
     
         10 . The method of  claim 8 , wherein the turbulator is a wire matrix turbulator. 
     
     
         11 . The method of  claim 8 , further comprising preheating feedwater in an economizer of the OTSG, then further heating said feedwater in the OTSG sufficiently to make the steam, wherein the tubes with the turbulator that is a wire matrix turbulator are disposed in said economizer. 
     
     
         12 . The method of  claim 8 , further comprising injecting the steam into the wellbore. 
     
     
         13 . The method of  claim 8 , wherein the turbulator is disposed in an economizer section of the OTSG and alters fluid flow direction near the wall, thus decreasing the temperature gradient and limiting nucleate boiling and fouling. 
     
     
         14 . The method of  claim 8 , wherein the turbulator is disposed in a radiant section of the OTSG to increase the heat transfer area and lead to a more uniform temperature distribution so as to minimize the risk of local burnout caused by high temperature gradients at the wall. 
     
     
         15 . A method of generating steam for oil production, comprising:
 pre-heating feedwater in a steam generator within an economizer section fitted with a wire matrix turbulator;   converting the feedwater pre-heated in the economizer section to steam in a radiant section of the steam generator; and   injecting the steam into an oil reservoir.   
     
     
         16 . The method of  claim 15 , wherein said wire matrix turbulator comprises a coiled wire, wherein subsequent coils are radially shifted around a central axis, and wherein all coils slant in a direction of fluid flow. 
     
     
         17 . The method of  claim 15 , wherein said wherein wire matrix turbulator comprises a polymer coated wire. 
     
     
         18 . The method of  claim 15 , wherein said wire matrix turbulator comprises a polymeric wire or mesh. 
     
     
         19 . The method of  claim 15 , wherein said radiant section also includes the wire matrix turbulator. 
     
     
         20 . The method of  claim 15 , further comprising separating liquid from the steam output from the radiant section prior to the injecting into the oil reservoir.