Succinimide-based copolymers and use as hydrate inhibitors

Abstract

Copolymers having General Formula (I): in which R 1 is chosen from divalent C 4 -C 7 aliphatic groups and divalent C 4 -C 7 heteroaliphatic groups, optionally substituted with one or more C 1 -C 6 aliphatic groups, heteroatoms independently chosen from O, N, and S, or combinations thereof, where: the divalent C 4 -C 7 heteroaliphatic groups include one or two heteroatoms independently chosen from O, N, and S, and the maximum number of heteroatoms in R 1 is two; x is a molar fraction range chosen from 0.05 to 0.95; and y is a molar fraction range chosen from 0.05 to 0.95, where the summation of x and y equals 1. Methods for inhibiting formation of clathrate hydrates in a fluid capable of forming the clathrate hydrates. The methods include contacting the fluid with at least one copolymer of General Formula (I) under conditions suitable for forming the clathrate hydrates.

What is claimed is: 
     
         1 . A copolymer having General Formula (I): 
       
         
           
           
               
               
           
         
       
       in which:
 R 1  is chosen from divalent C 4 -C 7  aliphatic groups and divalent C 4 -C 7  heteroaliphatic groups, optionally substituted with one or more C 1 -C 6  aliphatic groups, heteroatoms independently chosen from O, N, and S, or combinations thereof, where:
 the divalent C 4 -C 7  heteroaliphatic groups comprise one or two heteroatoms independently chosen from O, N, and S, and 
 the maximum number of heteroatoms in R 1  is two; 
 
 x is a molar fraction range chosen from 0.05 to 0.95; and 
 y is a molar fraction range chosen from 0.05 to 0.95, where the summation of x and y equals 1. 
 
     
     
         2 . The copolymer of  claim 1 , where R 1  is chosen from divalent C 4 -C 6  linear aliphatic groups. 
     
     
         3 . The copolymer of  claim 1 , where R 1  is substituted with one or more C 1 -C 3  linear aliphatic groups, C 1 -C 3  branched aliphatic groups, or combinations thereof. 
     
     
         4 . The copolymer of  claim 1 , where R 1  is substituted with one heteroatom independently chosen from O, N, and S. 
     
     
         5 . The copolymer of  claim 1 , where:
 R 1  is substituted with one heteroatom, and   the one heteroatom is O.   
     
     
         6 . The copolymer of  claim 1 , where 
       
         
           
           
               
               
           
         
       
       is chosen from 
       
         
           
           
               
               
           
         
       
     
     
         7 . The copolymer of  claim 1 , where:
 x is a molar fraction range of from 0.15 to 0.85 and   y is a molar fraction range of from 0.15 to 0.85.   
     
     
         8 . The copolymer of  claim 1 , where: 
       
         
           
           
               
               
           
         
       
       is chosen from 
       
         
           
           
               
               
           
         
         x is a molar fraction range of from 0.3 to 0.7 and 
         y is a molar fraction range of from 0.3 to 0.7. 
       
     
     
         9 . The copolymer of  claim 1 , where the viscosity average molecular weight of the copolymer is in the range of from 1,000 g/mol to 20,000 g/mol. 
     
     
         10 . A method for inhibiting formation of clathrate hydrates in a fluid capable of forming the clathrate hydrates, the method comprising:
 contacting the fluid with at least one copolymer of General Formula (I) under conditions suitable for forming the clathrate hydrates:   
       
         
           
           
               
               
           
         
         
           in which:
 R 1  is chosen from divalent C 4 -C 7  aliphatic groups and divalent C 4 -C 7  heteroaliphatic groups, optionally substituted with one or more C 1 -C 6  aliphatic groups, heteroatoms independently chosen from O, N, and S, or combinations thereof, where:
 the divalent C 4 -C 7  heteroaliphatic groups comprise one or two heteroatoms independently chosen from O, N, and S, and 
 where the maximum number of heteroatoms in R 1  is two; 
 
 x is a molar fraction range chosen from 0.05 to 0.95; and 
 y is a molar fraction range chosen from 0.05 to 0.95, where the summation of x and y equals 1. 
 
         
       
     
     
         11 . The method of  claim 10 , where the fluid comprises water host molecules and natural gas guest molecules chosen from methane, ethane, propane, butane, pentane, carbon dioxide, hydrogen sulfide, nitrogen, condensate thereof, or combinations thereof. 
     
     
         12 . The method of  claim 10 , where:
 the clathrate hydrates comprise SI clathrate hydrates, SII clathrate hydrates, SH clathrate hydrates, or combinations thereof, and   the contacting inhibits formation of the SI clathrate hydrates, the SII clathrate hydrates, the SH clathrate hydrates, or the combinations thereof.   
     
     
         13 . The method of  claim 10 , where the contacting inhibits the formation of the clathrate hydrates at a first subcooling temperature of from 0° C. to 4.0° C. 
     
     
         14 . The method of  claim 10 , where the contacting inhibits the formation of the clathrate hydrates at a second subcooling temperature of from 4.0° C. to 10.0° C. 
     
     
         15 . The method of  claim 10 , where the contacting inhibits the formation of the clathrate hydrates in a pressure range of from 40 bars to 200 bars. 
     
     
         16 . The method of  claim 10 , where the fluid is contacted with a composition comprising the at least one copolymer of General Formula (I) and one or more additives, corrosion inhibitors, scale inhibitors, thermodynamic hydrate inhibitors, low dose hydrate inhibitors, anti-agglomerates, solvents, or combinations thereof. 
     
     
         17 . The method of  claim 10 , where:
 R 1  is chosen from divalent C 4 -C 6  linear aliphatic groups and divalent C 4 -C 6  linear heteroaliphatic groups,   x is a molar fraction range of from 0.15 to 0.85 and   y is a molar fraction range of from 0.15 to 0.85.   
     
     
         18 . The method of  claim 10 , where: 
       
         
           
           
               
               
           
         
       
       is chosen from 
       
         
           
           
               
               
           
         
         x is a molar fraction of 0.5, and 
         y is a molar fraction of 0.5. 
       
     
     
         19 . The method of  claim 10 , where the fluid is contacted with the at least one copolymer at a tie-in platform. 
     
     
         20 . The method of  claim 10 , where the fluid is flowing in a pipeline.