Asphaltene inhibitors for squeeze applications

Abstract

Reaction products of polymeric alkyl phenol formaldehyde resins are useful as additives to inhibit or prevent the deposition or precipitation of asphaltenes in hydrocarbon fluids, particularly crude oil produced from a subterranean formation. These reaction products are formed by reacting a polymeric alkyl phenol formaldehyde resin with a co-reactant having functional groups including, but not necessarily limited to, amines, esters, silanes, ketones, epoxides, alkoxides, aryloxides, halogens, alkali metals, alkali earth metals, acetamides, non-metal oxides, metal oxides, where the co-reactant optionally has a carbon chain length between 1 and 22 and the reaction is conducted in the presence of at least one of various solvents. In one non-limiting embodiment, the co-reactant is a silicon derivative. The asphaltene inhibitors have utility when injected into a subterranean formation while oil production temporarily halts, a process called “squeezing,” because they are retained to a degree in the formation as the crude oil is produced.

What is claimed is: 
     
         1 . A reaction product of:
 an organic polymer selected from the group including, but not limited to, alkylphenol formaldehyde resins, alkylphenol formaldehyde amine resins, polyalkylsuccinic anhydrides, polyalkylsuccinic anhydride pentaerythritol condensate polymers, maleic anhydride alpha olefin polyesters, maleic anhydride fatty amine polyamides, sorbitan polyesters, alkyl polyacrylate esters and combinations thereof, with   a co-reactant having functional groups selected from the group consisting of amines, esters, silanes, ketones, epoxides, alkoxides, aryloxides, halogens, alkali metals, alkali earth metals, acetamides, non-metal oxides, metal oxides and combinations thereof and where the co-reactant may be one previously specified having a carbon chain length between 1 and 22 carbons.   
     
     
         2 . The reaction product of  claim 1  where the co-reactant is a silicon derivative of the formula SiR 1 R 2 R 3 R 4  where each R n  is independently selected from halogen, alkyl, O-alkyl, aryl, and O-aryl groups; where the alkyl groups are straight or branched and the alkyl groups and aryl groups may have from 1 to 22 carbon atoms. 
     
     
         3 . The reaction product of  claim 2  where functional groups of the co-reactant takes part in the reaction to a degree of from about 0.01 mole % to about 90 mole %. 
     
     
         4 . The reaction product of  claim 1  where the organic polymer is a polymeric alkyl phenol formaldehyde resin with a weight average molecular weight of from about 1000 to about 30,000 daltons. 
     
     
         5 . The reaction product of  claim 1  where the organic polymer is a polymeric alkyl phenol formaldehyde resin with a weight average molecular weight of from about 1000 to about 30,000 daltons, and where the co-reactant is a silicon derivative of the formula SiR 1 R 2 R 3 R 4  where each R n  is independently selected from halogen, alkyl, O-alkyl, aryl, and O-aryl groups, where the alkyl groups are straight or branched and the alkyl groups and aryl groups may have from 1 to 22 carbon atoms. 
     
     
         6 . The reaction product of  claim 1  where the organic polymer is nonylphenol resin and the co-reactant is a silane. 
     
     
         7 . A reaction product of:
 an organic polymer selected from the group including, but not limited to, alkylphenol formaldehyde resins, alkylphenol formaldehyde amine resins, polyalkylsuccinic anhydrides, polyalkylsuccinic anhydride pentaerythritol condensate polymers, maleic anhydride alpha olefin polyesters, maleic anhydride fatty amine polyamides, sorbitan polyesters, alkyl polyacrylate esters and combinations thereof, where the organic polymer is a polymeric alkyl phenol formaldehyde resin with a weight average molecular weight of from about 1300 to about 12,000 daltons, with   a co-reactant of the formula SiR 1 R 2 R 3 R 4  where each R n  is independently selected from halogen, alkyl, O-alkyl, aryl, and O-aryl groups; where the alkyl groups are straight or branched and the alkyl groups and aryl groups may have from 1 to 22 carbon atoms.   
     
     
         8 . The reaction product of  claim 7  where functional groups of the co-reactant takes part in the reaction to a degree of from about 0.01 mole % to about 90 mole %.