Well completion spacer fluids containing fibers

Abstract

Well completion spacer fluids containing fibers and methods of using the spacer fluids are provided. A method of the invention for displacing a first fluid from a well bore with an incompatible second fluid comprises the following steps. A spacer fluid is placed between the first and second fluids to separate the first and second fluids and to remove the first fluid from the walls of the well bore. Thereafter, the first fluid and the spacer fluid are displaced from the well bore with the second fluid. The spacer fluid comprises water, a weighting material, a dispersing agent, a suspending agent and friction reducer and fibers. The spacer fluid containing the components mentioned above is preferably also foamed.

1 . A spacer fluid comprising: 
 water;    a weighting material;    a dispersing agent;    a suspending agent and friction reducer; and    fibers selected from the group consisting of polyester fibers, polyamide fibers, polyethylene fibers, polypropylene fibers, and other polyolefin fibers.    
   
   
       2 . The spacer fluid of  claim 1  wherein the weighting material is selected from the group consisting of barium sulfate, hematite, manganese tetraoxide and calcium carbonate.  
   
   
       3 . The spacer fluid of  claim 1  wherein the dispersing agent is selected from the group consisting of naphthalene sulfonate condensed with formaldehyde, sodium polyacrylate, a terpolymer of acrylic acid, alkyloxybenzene sulfonate and methally sulfonate, formaldehyde, acetone, bisulfite condensate, melamine sulfonate formaldehyde condensate, and mixtures thereof.  
   
   
       4 . The spacer fluid of  claim 1  wherein the suspending agent and friction reducer is selected from the group consisting of sepiolite, whelan gum, xanthan gum, hydroxyethyl cellulose, bentonite, attapulgite, and mixtures thereof.  
   
   
       5 . The spacer fluid of  claim 1  wherein the fibers comprise hydrophilic fibers.  
   
   
       6 . The spacer fluid of  claim 1  wherein the fibers comprise hydrophilic polypropylene fibers.  
   
   
       7 . The spacer fluid of  claim 1  wherein the spacer fluid further comprises at least one additive selected from the group consisting of a well bore wall scouring material and a defoamer.  
   
   
       8 . The spacer fluid of  claim 1:   wherein the weighting material comprises barium sulfate;    wherein the dispersing agent comprises naphthalene sulfonate condensed with formaldehyde;    wherein the suspending agent and friction reducer comprises xanthan gum; and    wherein the fibers comprise hydrophilic fibers.    
   
   
       9 . The spacer fluid of  claim 1  wherein: 
 the weighting material is present in the spacer fluid in an amount up to about 745 pounds per barrel of the water present in the spacer fluid;    the dispersing agent is present in the spacer fluid in an amount up to about 5% by weight of the water present in the spacer fluid;    the suspending agent and friction reducer is present in the spacer fluid in an amount in the range of from about 2 pounds to about 10 pounds per barrel of the water present in the spacer fluid; and    the fibers are present in the spacer fluid in an amount in the range of from about 1/16 pound to about ¼ pound per barrel of the spacer fluid.    
   
   
       10 . A well completion fluid comprising a foamed spacer fluid containing fibers.  
   
   
       11 . The well completion fluid of  claim 10  wherein the fibers are selected from the group consisting of polyester fibers, polyamide fibers, polyethylene fibers, polypropylene fibers, and other polyolefin fibers.  
   
   
       12 . The well completion fluid of  claim 10  wherein the fibers comprise hydrophilic fibers.  
   
   
       13 . The well completion fluid of  claim 10  wherein the fibers comprise hydrophilic polypropylene fibers.  
   
   
       14 . The well completion fluid of  claim 10  wherein the fibers are present in the foamed spacer fluid in an amount in the range of from about 1/16 pound to about ¼ pound per barrel of the foamed spacer fluid.  
   
   
       15 . The well completion fluid of  claim 10  wherein the foamed spacer fluid further comprises at least one additive selected from the group consisting of a weighting material, a dispersing agent, a suspending agent and friction reducer, and a well bore wall scouring material.  
   
   
       16 . A foamed spacer fluid comprising: 
 water;    a weighting material;    a dispersing agent;    a suspending agent and friction reducer;    fibers;    a foaming and foam stabilizing surfactant; and    a gas.    
   
   
       17 . The foamed spacer fluid of  claim 16  wherein the fibers are selected from the group consisting of polyester fibers, polyamide fibers, polyethylene fibers, polypropylene fibers, and other polyolefin fibers.  
   
   
       18 . The foamed spacer fluid of  claim 16  wherein the fibers comprise hydrophilic fibers.  
   
   
       19 . The foamed spacer fluid of  claim 16  wherein the fibers comprise hydrophilic polypropylene fibers.  
   
   
       20 . The foamed spacer fluid of  claim 16  wherein the foamed spacer fluid further comprises a well bore wall scouring material.  
   
   
       21 . The foamed spacer fluid of  claim 16  wherein the foaming and foam stabilizing surfactant is selected from the group consisting of a mixture of an ethoxylated alcohol ether sulfate surfactant, an alkyl or alkene amidopropyl betaine surfactant and an alkyl or alkene amidopropyl dimethyl amine oxide surfactant, and a mixture of an alpha-olefmic sulfonate surfactant and an alkyl or alkene amidopropyl betaine surfactant.  
   
   
       22 . The foamed spacer fluid of  claim 16  wherein: 
 the weighting material comprises barium sulfate;    the dispersing agent comprises naphthalene sulfonate condensed with formaldehyde;    the suspending agent and friction reducer comprises xanthan gum;    the foaming and foam stabilizing surfactant comprises a mixture of an ethoxylated alcohol ether sulfate surfactant, an alkyl or alkene amidopropyl betaine surfactant and an alkyl or alkene amidopropyl dimethyl amine oxide surfactant; and    the fibers comprise hydrophilic fibers.    
   
   
       23 . The foamed spacer fluid of  claim 16  wherein: 
 the weighting material is present in the foamed spacer fluid in an amount up to about 745 pounds per barrel of the water present in the foamed spacer fluid;    the dispersing agent is present in the foamed spacer fluid in an amount up to about 5% by weight of the water present in the foamed spacer fluid;    the suspending agent and friction reducer is present in the foamed spacer fluid in an amount in the range of from about 2 pounds to about 10 pounds per barrel of the water present in the foamed spacer fluid; and    the fibers are present in the foamed spacer fluid in an amount in the range of from about 1/16 pound to about ¼ pound per barrel of the foamed spacer fluid.