Well plug additive, well plug treatment fluid made therefrom, and method of plugging a well

Abstract

For well plug treatment to plug an abandoned well, a well plug additive including a dry mixture of water soluble crosslinkable polymer, a crosslinking agent, and filter aid, and optionally, a reinforcing material preferably of fibers and/or comminuted plant materials. The method of forming a well plug fluid includes contacting the additive with water or an aqueous solution, with a method of plugging the well further including the step of injecting the fluid into the wellbore.

1 . A well plug additive comprising a dry mixture of water soluble crosslinkable polymer, a crosslinking agent, and a filter aid.  
   
   
       2 . The additive of  claim 1 , wherein the filter aid is selected from the group consisting of diatomaceous earth, perlite, glass beads, magnesium silicate, solid thermoplastic or thermoset polymer beads, talc, and calcium silicate.  
   
   
       3 . The additive of  claim 2 , wherein the polymer is an a carboxylate-containing polymer, and the crosslinking agent is selected from the group consisting of chromium (III) carboxylate complexes, aldehydes, dialdehydes, formaldehydes, glutaraldehyde, dichromates, titanium chelates, phenols, substituted phenols, ethers, aluminum citrate, and aluminates.  
   
   
       4 . The additive of  claim 3 , wherein the filter aid comprises at least one of diatomaceous earth or pearlite.  
   
   
       5 . The additive of  claim 4 , wherein the polymer comprises a low molecular weight polymer having a molecular weight less than 500,000, and a high molecular weight polymer having a molecular weight of at least 500,000.  
   
   
       6 . The additive of  claim 4 , wherein the polymer is a water soluble, carboxylate containing acrylamide, and the crosslinking agent is a chromium (III) carboxylate complex.  
   
   
       7 . The additive of  claim 6 , wherein the filter aid is diatomaceous earth.  
   
   
       8 . The additive of  claim 6 , wherein the filter aid is pearlite.  
   
   
       9 . The additive of  claim 6 , further comprising reinforcing material selected from the group consisting of hydrophilic fibers, hydrophobic fibers, and comminuted plant material.  
   
   
       10 . A well fluid comprising a well plug fluid, water soluble crosslinkable polymer, a crosslinking agent, and a filter aid.  
   
   
       11 . The well fluid of  claim 10 , wherein the filter aid is selected from the group consisting of diatomaceous earth, perlite, glass beads, magnesium silicate, solid thermoplastic or thermoset polymer beads, talc, and calcium silicate.  
   
   
       12 . The well fluid of  claim 11 , wherein the polymer is an a carboxylate-containing polymer, and the crosslinking agent is selected from the group consisting of chromium (III) carboxylate complexes, aldehydes, dialdehydes, formaldehydes, glutaraldehyde, dichromates, titanium chelates, phenols, substituted phenols, ethers, aluminum citrate, and aluminates.  
   
   
       13 . The well fluid of  claim 12 , wherein the filter aid comprises at least one of diatomaceous earth or pearlite.  
   
   
       14 . The well fluid of  claim 13 , wherein the polymer comprises a low molecular weight polymer having a molecular weight less than 500,000, and a high molecular weight polymer having a molecular weight of at least 500,000.  
   
   
       15 . The well fluid of  claim 13 , wherein the polymer is a water soluble, carboxylate containing acrylamide, and the crosslinking agent is a chromium (III) carboxylate complex.  
   
   
       16 . The well fluid of  claim 15 , wherein the filter aid is diatomaceous earth.  
   
   
       17 . The well fluid of  claim 15 , wherein the filter aid is pearlite.  
   
   
       18 . The well fluid of  claim 15 , further comprising reinforcing material selected from the group consisting of hydrophilic fibers, hydrophobic fibers, and comminuted plant material.  
   
   
       19 . A method of modifying a well plug fluid comprising: 
 (a) contacting the well plug fluid with a water soluble crosslinkable polymer, crosslinking agent, and filter aid to form a modified well plug fluid.    
   
   
       20 . The method of  claim 19 , wherein the filter aid is selected from the group consisting of diatomaceous earth, perlite, glass beads, magnesium silicate, solid thermoplastic or thermoset polymer beads, talc, and calcium silicate.  
   
   
       21 . The method of  claim 20 , wherein the polymer is an a carboxylate-containing polymer, and the crosslinking agent is selected from the group consisting of chromium (III) carboxylate complexes, aldehydes, dialdehydes, formaldehydes, glutaraldehyde, dichromates, titanium chelates, phenols, substituted phenols, ethers, aluminum citrate, and aluminates.  
   
   
       22 . The method of  claim 21 , wherein the filter aid comprises at least one of diatomaceous earth or pearlite.  
   
   
       23 . The method of  claim 22 , wherein the polymer comprises a low molecular weight polymer having a molecular weight less than 1,000,000, and a high molecular weight polymer having a molecular weight of at least 1,000,000.  
   
   
       24 . The method of  claim 22 , wherein the polymer is a water soluble, carboxylate containing acrylamide, and the crosslinking agent is a chromium (III) carboxylate complex.  
   
   
       25 . The method of  claim 24 , wherein the filter aid is diatomaceous earth.  
   
   
       26 . The method of  claim 24 , wherein the filter aid is pearlite.  
   
   
       27 . The method of  claim 19 , wherein the water soluble crosslinkable polymer, crosslinking agent, and filter aid, are all in solid form.  
   
   
       28 . A method of circulating a well plug fluid in a welbore penetrating a subterranean formation, comprising: 
 (a) providing a well plug fluid comprising water or an aqueous solution, water soluble crosslinkable polymer, a crosslinking agent, and a filter aid;    (b) circulating the well plug fluid in the wellbore.    
   
   
       29 . The method of  claim 28 , wherein the filter aid is selected from the group consisting of diatomaceous earth, perlite, glass beads, magnesium silicate, solid thermoplastic or thermoset polymer beads, talc, and calcium silicate.  
   
   
       30 . The method of  claim 29 , wherein the polymer is an a carboxylate-containing polymer, and the crosslinking agent is selected from the group consisting of chromium (III) carboxylate complexes, aldehydes, dialdehydes, formaldehydes, glutaraldehyde, dichromates, titanium chelates, phenols, substituted phenols, ethers, aluminum citrate, and aluminates.  
   
   
       31 . The method of  claim 30 , wherein the filter aid comprises at least one of diatomaceous earth or pearlite.  
   
   
       32 . The method of  claim 31 , wherein the polymer comprises a low molecular weight polymer having a molecular weight less than 500,000, and a high molecular weight polymer having a molecular weight of at least 500,000.  
   
   
       33 . The method of  claim 31 , wherein the polymer is a water soluble, carboxylate containing acrylamide, and the crosslinking agent is a chromium (III) carboxylate complex.  
   
   
       34 . The method of  claim 33 , wherein the filter aid is diatomaceous earth.  
   
   
       35 . The method of  claim 33 , wherein the filter aid is pearlite.  
   
   
       36 . The method of  claim 33 , further comprising reinforcing material selected from the group consisting of hydrophilic fibers, hydrophobic fibers, and comminuted plant material.  
   
   
       37 . A method of modifying a well plug fluid circulating in a wellbore penetrating a subterranean formation, comprising: 
 (a) introducing a water soluble crosslinkable polymer, crosslinking agent, and filter aid to the circulating well plug fluid.    
   
   
       38 . The method of  claim 37 , wherein the filter aid is selected from the group consisting of diatomaceous earth, perlite, glass beads, magnesium silicate, solid thermoplastic or thermoset polymer beads, talc, and calcium silicate.  
   
   
       39 . The method of  claim 38 , wherein the polymer is an a carboxylate-containing polymer, and the crosslinking agent is selected from the group consisting of chromium (III) carboxylate complexes, aldehydes, dialdehydes, formaldehydes, glutaraldehyde, dichromates, titanium chelates, phenols, substituted phenols, ethers, aluminum citrate, and aluminates.  
   
   
       40 . The method of  claim 39 , wherein the filter aid comprises at least one of diatomaceous earth or pearlite.  
   
   
       41 . The method of  claim 40 , wherein the polymer comprises a low molecular weight polymer having a molecular weight less than 500,000, and a high molecular weight polymer having a molecular weight of at least 500,000.  
   
   
       42 . The method of  claim 40 , wherein the polymer is a water soluble, carboxylate containing acrylamide, and the crosslinking agent is a chromium (III) carboxylate complex.  
   
   
       43 . The method of  claim 42 , wherein the filter aid is diatomaceous earth.  
   
   
       44 . The method of  claim 42 , wherein the filter aid is pearlite.  
   
   
       45 . The method of  claim 37 , wherein the water soluble crosslinkable polymer, crosslinking agent, and filter aid, are all in solid form.