System and method for creating flowable hydrate slurries in production fluids

Abstract

Methods and systems are provided for producing hydrocarbons from production fluids that have water as an external phase. An exemplary embodiment provides a method that comprises producing a production fluid having water as the external phase and injecting an amount of a thermodynamic hydrate inhibitor into the production fluid, wherein the amount is adjusted to allow hydrate formation to occur while retaining liquid water as the external phase. The water and thermodynamic hydrate inhibitor may be separated from the production fluid and a purified hydrocarbon stream may be produced.

1 . A method for forming a flowable hydrate slurry in a production fluid that has water as an external phase, comprising:
 injecting an amount of a thermodynamic hydrate inhibitor (THI) into the production fluid, wherein the amount of the THI added is controlled to allow formation of a hydrate while retaining the water as the external phase.   
     
     
         2 . The method of  claim 1 , further comprising monitoring a phase behavior of the production fluid after the hydrate forms to determine that the water is the external phase. 
     
     
         3 . The method of  claim 2 , further comprising adjusting the amount of the THI injected into the production fluid to select the water as the external phase. 
     
     
         4 . The method of  claim 1 , further comprising adding an anti-agglomerate agent (AA) to the production fluid. 
     
     
         5 . The method of  claim 1 , further comprising adding a kinetic hydrate inhibitor to the production fluid. 
     
     
         6 . The method of  claim 1 , wherein the THI comprises glycols, alcohols, salts, or any combinations thereof. 
     
     
         7 . The method of  claim 1 , further comprising passing the production fluid through a static mixer after injecting the THI. 
     
     
         8 . The method of  claim 1 , wherein the amount of the THI injected into the production fluid is less than about 5% by wt. in the water phase before the formation of the hydrate. 
     
     
         9 . A system for producing a production fluid in which water is an external phase, comprising:
 a pipeline configured to carry the production fluid; and   an injector configured to inject an amount of a thermodynamic hydrate inhibitor (THI) into the production fluid, wherein the amount of the THI added will allow formation of a hydrate while retaining the water as the external phase.   
     
     
         10 . The system of  claim 9 , further comprising a static mixer in the pipeline downstream of the injector. 
     
     
         11 . The system of  claim 9 , further comprising an analyzer to determine a phase behavior of the production fluid. 
     
     
         12 . The system of  claim 11 , further comprising an addition system configured to change the amount of the THI added in order to select the water as the external phase. 
     
     
         13 . The system of  claim 9 , comprising a processing facility configured to remove the water and the THI from the production fluid. 
     
     
         14 . The system of  claim 9 , comprising a processing facility configured to process the hydrocarbon for shipping in a pipeline. 
     
     
         15 . The system of  claim 9 , comprising a hydrocarbon field configured to produce the production fluid. 
     
     
         16 . The system of  claim 15 , wherein the production fluid comprises a natural gas. 
     
     
         17 . The system of  claim 15 , wherein the production fluid comprises an oil. 
     
     
         18 . A method for producing a hydrocarbon, comprising:
 producing a production fluid having water as an external phase;   injecting an amount of a thermodynamic hydrate inhibitor (THI) into the production fluid, wherein the amount is adjusted to allow hydrate formation to occur while retaining water as the external phase;   separating out the water and the THI from the production fluid; and   producing a purified hydrocarbon stream.   
     
     
         19 . The method of  claim 18 , further comprising monitoring a phase behavior of the production fluid after the injection of the THI. 
     
     
         20 . The method of  claim 18 , wherein producing the purified hydrocarbon stream comprises producing a liquefied natural gas. 
     
     
         21 . The method of  claim 18 , further comprising separating the THI from the water and reinjecting the THI into the production fluid.