Diverting agents for water shut off

Abstract

A method of retarding the flow of water in a subterranean formation that includes injecting a gelling pill into the formation, the gelling pill comprising: brine; a crosslinkable polymer; and a crosslinkant; and allowing the crosslinkable polymer to crosslink to form a gel in the subterranean formation is disclosed. A water absorbing polymer is optionally included.

1 . A method of retarding the flow of water in a subterranean formation, comprising:
 injecting a gelling pill into the formation, the gelling pill comprising:
 brine; 
 a crosslinkable polymer; and 
 a crosslinkant; and 
   allowing the crosslinkable polymer to crosslink to form a gel in the subterranean formation.   
     
     
         2 . The method of  claim 1 , wherein the gelling pill, when gelled, retards water flow therethrough. 
     
     
         3 . The method of  claim 1 , further comprising:
 producing oil from the subterranean formation.   
     
     
         4 . The method of  claim 1 , further comprising:
 injecting a driving fluid into the subterranean formation.   
     
     
         5 . The method of  claim 1 , wherein the gelling pill further comprises a crosslink initiator. 
     
     
         6 . The method of  claim 1 , wherein the crosslinkable polymer comprises at least one of xanthan, guar, hydroxyalkylguar, carboxyalkylhydroxyalkylguar, scleroglucan, wellan, gellan, and diutan. 
     
     
         7 . The method of  claim 6 , wherein the crosslinkable polymer comprises xanthan gum. 
     
     
         8 . The method of  claim 1 , wherein the crosslinkant comprises at least one of boron, calcium, zinc, titanium, and zirconium. 
     
     
         9 . The method of  claim 8 , wherein the crosslinkant comprises solid borates of alkali metals and/or alkaline earth metals. 
     
     
         10 . The method of  claim 9 , further comprising:
 allowing the solid borates to permeate into the formation.   
     
     
         11 . The method of  claim 1 , wherein the gelling pill further comprises a water absorbing polymer. 
     
     
         12 . The method of  claim 10 , wherein the water absorbing polymer comprises crosslinked polyacrylamide, polyacrylate, or copolymers thereof. 
     
     
         13 . A method of retarding the flow of water in a subterranean formation, comprising:
 introducing an effective amount of a gelling pill into flow channels in the formation,
 the gelling pill comprising: 
 brine; 
 a crosslinkable polymer; 
 a crosslinkant; and 
 a water absorbing polymer 
   allowing the water absorbing polymer to permeate a region of the formation surrounding the flow channels; and   allowing the crosslinkable polymer to crosslink to form a gel in the flow channel in the formation.   
     
     
         14 . The method of  claim 13 , wherein the gelling pill, when gelled, retards water flow therethrough. 
     
     
         15 . The method of  claim 13 , further comprising:
 producing oil from the subterranean formation.   
     
     
         16 . The method of  claim 13 , further comprising:
 injecting a driving fluid into the subterranean formation.   
     
     
         17 . The method of  claim 13 , wherein the water absorbing polymer absorbs water that flows into the region of the formation surrounding the flow channels having the gel formed therein. 
     
     
         18 . The method of  claim 13 , wherein the gelling pill further comprises a crosslink initiator. 
     
     
         19 . The method of  claim 13 , wherein the crosslinkable polymer comprises at least one of xanthan, guar, hydroxyalkylguar, carboxyalkylhydroxyalkylguar, scleroglucan, wellan, gellan, and diutan. 
     
     
         20 . The method of  claim 19 , wherein the crosslinkable polymer comprises xanthan gum. 
     
     
         21 . The method of  claim 13 , wherein the crosslinkant comprises at least one of boron, calcium, zinc, titanium, and zirconium. 
     
     
         22 . The method of  claim 21 , wherein the crosslinkant comprises solid borates of alkali metals and/or alkaline earth metals. 
     
     
         23 . The method of  claim 13 , wherein the water absorbing polymer comprises crosslinked polyacrylamide, polyacrylate, or copolymers thereof. 
     
     
         24 . A method of retarding the flow of water in a subterranean formation, comprising:
 injecting a gelling pill into flow channels in the formation, the gelling pill comprising:
 brine; 
 a crosslinkable xanthan gum; and 
 borate crosslinkant solids; and 
   allowing the borate crosslinkant solids to permeate a region of the formation surrounding the flow channels; and   triggering crosslinking between the xanthan gum and borate crosslink with magnesium oxide to form a gel in the subterranean formation.