Methods for enhancing aqueous fluid recovery form subterranean formations

Abstract

Methods of improving load recovery using hydrophobic coatings to enhance the recovery of treatment fluids from subterranean formations may include the use of hydrophobic coating agents. In particular, such methods may include the steps of coating a plurality of particulates so as to form a plurality of hydrophobically-coated particulates. The presence of these hydrophobically-coated particulates downhole may enhance the recovery of aqueous treatment fluids.

1 . A method of enhancing the recovery of an aqueous treatment fluid from a subterranean formation comprising: 
 providing a plurality of particulates;    coating the plurality of particulates with a hydrophobic coating agent so as to form a plurality of hydrophobically-coated particulates;    providing a carrier fluid;    mixing the plurality of hydrophobically-coated particulates with the carrier fluid so as to form a pumpable slurry;    introducing the plurality of hydrophobically-coated particulates into the subterranean formation;    placing the plurality of hydrophobically-coated particulates in the subterranean formation; and    allowing a treatment fluid to flow back through the plurality of hydrophobically-coated particulates to recover a treatment fluid that was previously-introduced into the subterranean formation.    
   
   
       2 . The method of  claim 1  wherein the hydrophobic coating agent comprises a polyamide.  
   
   
       3 . The method of  claim 1  wherein the hydrophobic coating agent is a polycarbonate, a polycarbamate, or a natural resin.  
   
   
       4 . The method of  claim 1  wherein the hydrophobic coating agent comprises a reaction product of a compound having a chlorosilyl group and an alkysilane.  
   
   
       5 . The method of  claim 1  wherein the hydrophobic coating agent comprises a polymer of a silane compound having a fluoroalkyl-group.  
   
   
       6 . The method of  claim 1  wherein the hydrophobic coating agent is a silicon-oxide layer, a hybrid organo-silicon oxide anchor layer, or a mixture thereof.  
   
   
       7 . The method of  claim 6  further comprising coating a chloroalkysilane by vapor-deposition on the surface of the hydrophobically-coated particulates  
   
   
       8 . The method of  claim 1  wherein the hydrophobic coating agent comprises a polymer of a fluoroalkyl-group containing silane compound.  
   
   
       9 . The method of  claim 1  wherein the hydrophobic coating agent comprises lecithin.  
   
   
       10 . The method of  claim 3  wherein the coating of the plurality of particulates occurs before the mixing of the plurality of hydrophobically-coated particulates with the carrier fluid.  
   
   
       11 . The method of  claim 1  wherein the hydrophobic coating agent comprises a polyamide, a solvent, and a surfactant.  
   
   
       12 . The method of  claim 11  wherein the surfactant is lauryl sulfate, a polycarbonate, a polyacetal, a poly(orthoester), a polyesteramide, or an alkyl sulfate having an alkyl chain from about 6 carbon atoms to about 21 carbon atoms.  
   
   
       13 . The method of  claim 11  wherein the solvent comprises isopropyl alcohol.  
   
   
       14 . The method of  claim 11  wherein the surfactant comprises cocodiamine.  
   
   
       15 . The method of  claim 14  wherein the solvent comprises isopropyl alcohol.  
   
   
       16 . A method of enhancing the recovery of an aqueous treatment fluid from a subterranean formation comprising: 
 providing a plurality of hydrophobically-coated particulates;    placing the plurality of hydrophobically-coated particulates in the subterranean formation; and    allowing a treatment fluid to flow back through the plurality of hydrophobically-coated particulates to recover a treatment fluid that was previously-introduced into the subterranean formation.    
   
   
       17 . The method of  claim 16  wherein the hydrophobic coating agent comprises a polyamide.  
   
   
       18 . The method of  claim 17  wherein the hydrophobic coating agent further comprises an solvent wherein the solvent is isopropyl alcohol and a surfactant.  
   
   
       19 . A method of recovering a previously-introduced aqueous treatment fluid from a subterranean formation comprising: 
 providing a plurality of particulates;    introducing the plurality of particulates into a subterranean well bore;    introducing a hydrophobic coating agent into the subterranean well bore;    allowing the hydrophobic coating agent to coat the plurality of particulates so as to form a plurality of hydrophobically-coated particulates;    allowing the plurality of hydrophobically-coated particulates to be placed in a portion of the subterranean formation; and    allowing the previously-introduced aqueous treatment fluid to flow back through the plurality of hydrophobically-coated particulates.    
   
   
       20 . The method of  claim 16  wherein the hydrophobic coating agent comprises a polyamide, a solvent wherein the solvent is isopropyl alcohol, and a surfactant wherein the surfactant is cocodiamine.