Water removal from anti-agglomerate ldhis

Abstract

A method of controlling corrosion in a subsea pipeline is disclosed which includes supplying a low dose inhibitor stream (LDHI) comprised of a quaternary amine and drying with a desiccant.

What is claimed is: 
     
         1 . A method of controlling corrosion in a subsea pipeline comprising:
 supplying a low dose inhibitor stream (“LDHI”) comprising a quaternary amine;   combining an internal desiccant with the LDHI stream to form a dried LDHI stream; and   injecting the dried LDHI into the subsea pipeline.   
     
     
         2 . The method of  claim 1 , wherein the internal desiccant is an anhydride represented by the following formula: 
       
         
           
           
               
               
           
         
         wherein R1 and R2 each comprise a hydrocarbon from 1 to 10 carbon atoms. 
       
     
     
         3 . The method of  claim 2 , wherein R1 and R2 comprise a heterocyclic, polycyclic, or substituted aromatic ring. 
     
     
         4 . The method of  claim 3 , wherein R1 and R2 are selected from the group consisting of acetic anhydride, succinic anhydride, maleic anhydride, propionic anhydride, butanoic anhydride, ethanoic anhydride, benzoic anhydride, methanoic-propane anhydride, phthalic anhydride, and mixtures thereof. 
     
     
         5 . The method of  claim 1 , wherein the internal desiccant is a metal oxide. 
     
     
         6 . The method of  claim 5 , wherein the internal desiccant is selected from the group consisting of a barium oxide, sodium pentoxide, or phosphorus pentoxide. 
     
     
         7 . The method of  claim 1 , wherein the internal desiccant is supplied continuously. 
     
     
         8 . The method of  claim 1 , further comprising filtering the LDHI stream or the dried LDHI stream before injecting. 
     
     
         9 . The method of  claim 8 , further comprising before the step of injecting the dried LDHI stream:
 monitoring a water content in the LDHI stream.   
     
     
         10 . A method of controlling corrosion in a subsea pipeline comprising:
 providing an LDHI stream, the LDHI stream containing water;   determining a first maximum allowable water content of the LDHI stream;   determining that a water content in the LDHI stream exceeds the first maximum allowable water content;   drying the LDHI stream based upon the water content in the LDHI stream exceeding the first maximum allowable water content, so as to form a dried LDHI stream; and   injecting the dried LDHI stream into the subsea pipeline.   
     
     
         11 . The method of  claim 10  further comprising before the injecting step: filtering the LDHI stream or the dried LDHI stream. 
     
     
         12 . The method of  claim 10  further comprising before the injecting step:
 monitoring the water content in the dried LDHI stream. 
 
     
     
         13 . The method of  claim 10 , further comprising:
 determining a second maximum allowable water content of the LDHI stream; and   after the drying the LDHI stream but before injecting the dried LDHI stream, determining that the water content in the dried LDHI stream exceeds the second maximum allowable water content.   
     
     
         14 . The method of  claim 13 , wherein the second maximum allowable water content is 0.5 volume % water. 
     
     
         15 . The method of  claim 10 , wherein the step of drying the LDHI stream is performed by contacting the LDHI stream with an external desiccant. 
     
     
         16 . The method of  claim 15 , wherein the external desiccant comprises a dessicant selected from the group consisting of: clay, silica gel, a molecular sieve, calcium oxide, calcium sulfate, activated charcoal, calcium chloride, a metal salt, activated alumina, aerogel, benzophenone, calcium hydride, cobalt(II) chloride, copper(II) sulfate, lithium chloride, lithium hydride, lithium bromide, magnesium, magnesium sulfate, magnesium perchlorate, a sodium-potassium alloy, phosphorus pentoxide, potassium, potassium carbonate, sodium, sodium chlorate, sodium chloride, sodium hydroxide, sodium sulfate, sodium-benzophenone, sucrose, sulfuric acid, and any combination thereof. 
     
     
         17 . The method of  claim 16 , wherein the clay is a Montmorillonite clay. 
     
     
         18 . The method of  claim 16 , wherein the molecular sieve is a synthetic zeolite. 
     
     
         19 . The method of  claim 10 , wherein the first maximum allowable water content is 0.9 volume % water.