Permeable cement and sand control methods utilizing permeable cement in subterranean well bores

Abstract

Cement compositions useful in subterranean applications are provided. More particularly, permeable cement compositions for forming consolidated permeable cement masses in well bores to prevent sand influx into the well bores with produced fluids are provided. In one embodiment, the permeable cement compositions of the present invention comprise a hydraulic cement, water, and a degradable material capable of undergoing an irreversible degradation downhole selected from the group consisting of a degradable polymer selected from the group consisting of polysaccharides, chitins, chitosans, proteins, aliphatic polyesters, poly(lactides), poly(glycolides), poly(ε-caprolactones), poly(hydroxybutyrates), polyanhydrides, aliphatic polycarbonates, poly(orthoesters), poly(amino acids), poly(ethylene oxides), and polyphosphazenes; and a dehydrated salt.

1 . A permeable cement composition for use in subterranean operations comprising: 
 a hydraulic cement;    water,    and a degradable material selected from the group consisting of:    (i) a degradable polymer selected from the group consisting of polysaccharides, chitins, chitosans, proteins, aliphatic polyesters, poly(lactides), poly(glycolides), poly(ε-caprolactones), poly(hydroxybutyrates), polyanhydrides, aliphatic polycarbonates, poly(orthoesters), poly(amino acids), poly(ethylene oxides), and polyphosphazenes; and    (ii) a dehydrated salt.    
   
   
       2 . The composition of  claim 1  wherein the permeable cement composition further comprises a dispersant.  
   
   
       3 . The composition of  claim 1  wherein the hydraulic cement is selected from the group consisting of calcium, aluminum, silicon, oxygen, and sulfur.  
   
   
       4 . The composition of  claim 1  wherein the hydraulic cement is selected from the group consisting of a Portland cement, pozzolana cement, gypsum cement, high alumina content cement, silica cement, high alkalinity cement, and low-density cement.  
   
   
       5 . The composition of  claim 1  wherein the hydraulic cement is present in the permeable cement composition in an amount ranging from about 50% to about 60% by weight of the permeable cement composition.  
   
   
       6 . The composition of  claim 1  wherein the water is selected from the group consisting of fresh water, salt water, and brine.  
   
   
       7 . The composition of  claim 1  wherein the water is present in an amount ranging from about 15% to about 40% by weight of the permeable cement composition.  
   
   
       8 . The composition of  claim 1  wherein the permeable cement composition further comprises a fluid loss additive.  
   
   
       9 . The composition of  claim 1  wherein the permeable cement composition is mixed on-the-fly.  
   
   
       10 . The composition of  claim 1  wherein the degradable polymer further comprises a plasticizer.  
   
   
       11 . The composition of  claim 1  wherein the degradable material comprises a stereoisomer of a poly(lactide).  
   
   
       12 . The composition of  claim 1  wherein the dehydrated salt is selected from the group consisting of anhydrous sodium tetraborate and anhydrous boric acid.  
   
   
       13 . The composition of  claim 1  wherein the degradable material is present in an amount ranging from about 5% to about 70% by weight of the composition.  
   
   
       14 . The composition of  claim 1  wherein the degradable material comprises particles having a rod-like shape.  
   
   
       15 . The composition of  claim 1  wherein the cement is a Portland cement and present in an amount of from about 30% to about 70% by weight of the permeable cement composition; the water is fresh water and is present in an amount of from about 15% to about 40% by weight of the cement composition; and wherein the degradable material comprises a poly(lactic acid) particulate present in an amount of from about 5% to about 70% by weight of the permeable cement composition.  
   
   
       16 . A permeable cement mass useful in well bores penetrating a subterranean formation as a sand control means having voids created by a degradation of a degradable material selected from the group consisting of: 
 (i) a degradable polymer selected from the group consisting of polysaccharides, chitins, chitosans, proteins, aliphatic polyesters, poly(lactides), poly(glycolides), poly(ε-caprolactones), poly(hydroxybutyrates), polyanhydrides, aliphatic polycarbonates, poly(orthoesters), poly(amino acids), poly(ethylene oxides), and polyphosphazenes; and    (ii) a dehydrated salt.    
   
   
       17 . The composition of  claim 16  wherein the degradable polymer further comprises a plasticizer.  
   
   
       18 . The composition of  claim 16  wherein the degradable material comprises a stereoisomer of a poly(lactide).  
   
   
       19 . The composition of  claim 16  wherein the dehydrated salt is selected from the group consisting of anhydrous sodium tetraborate and anhydrous boric acid.  
   
   
       20 . The composition of  claim 16  wherein the degradable material is present in an amount ranging from about 5% to about 70% by weight of the composition.