Settable spacer fluids comprising pumicite and methods of using such fluids in subterranean formations

Abstract

Methods and compositions for the treatment of subterranean formations, and more specifically, treatment fluids containing pumicite and methods of using these treatment fluids in subterranean formations, are provided. An example of a method is a method of displacing a fluid in a well bore. Another example of a method is a method of separating fluids in a well bore in a subterranean formation. An example of a composition is a settable spacer fluid comprising pumicite, an activating agent, and a base fluid.

What is claimed is: 
     
         1 . A settable spacer fluid comprising pumicite, an activating agent, and a base fluid. 
     
     
         2 . The settable spacer fluid of  claim 1 , wherein the activating agent comprises at least one activating agent selected from the group consisting of: lime;
 calcium chloride; calcium bromide; sodium hexametaphosphate; sodium silicate; sodium sulfate; and any combination thereof.   
     
     
         3 . The settable spacer fluid of  claim 1 , further comprising a set accelerator. 
     
     
         4 . The settable spacer fluid of  claim 1 , wherein the pumicite is present in an amount from about 0.01% to about 90% by weight of the settable spacer fluid. 
     
     
         5 . The settable spacer fluid of  claim 1 , wherein the pumicite is present in an amount from about 1% to 20% by weight of the settable spacer fluid. 
     
     
         6 . The settable spacer fluid of  claim 1 , wherein the pumicite is present in an amount from about 10% to 40% by weight of the settable spacer fluid. 
     
     
         7 . The settable spacer fluid of  claim 1 , wherein the activating agent is present in an amount from about 0.01% to about 35% by weight of the settable spacer fluid. 
     
     
         8 . The settable spacer fluid of  claim 1 , wherein the activating agent is present in an amount from about 5% to about 10% by weight of the settable spacer fluid 
     
     
         9 . The settable spacer fluid of  claim 1 , wherein the base fluid comprises at least one fluid selected from the group consisting of: an aqueous-based fluid, an emulsion, a synthetic fluid, an oil-based fluid, and any combination thereof. 
     
     
         10 . The settable spacer fluid of  claim 1 , wherein the 300/3 ratio of the settable spacer fluid is from about 1 to about 50. 
     
     
         11 . The settable spacer fluid of  claim 1 , wherein the 300/3 ratio of the settable spacer fluid is from about 5 to about 20. 
     
     
         12 . The settable spacer fluid of  claim 1 , wherein the 300/3 ratio of the settable spacer fluid is from about 10 to about 15. 
     
     
         13 . The settable spacer fluid of  claim 1 , wherein the pumicite comprises less than 1% crystalline silica by weight. 
     
     
         14 . The settable spacer fluid of  claim 1 , wherein the pumicite comprises particulates that are sized to pass through a 20 mesh screen. 
     
     
         15 . The settable spacer fluid of  claim 1 , wherein the pumicite comprises particulates that are sized to pass through a 200 mesh screen. 
     
     
         16 . The settable spacer fluid of  claim 1 , wherein the pumicite comprises particulates that are sized to pass through a 325 mesh screen. 
     
     
         17 . The settable spacer fluid of  claim 1 , wherein the base fluid is present in an amount from about 15% to about 95% by weight of the settable spacer fluid. 
     
     
         18 . The settable spacer fluid of  claim 1 , wherein the base fluid is present in an amount from about 25% to about 85% by weight of the settable spacer fluid. 
     
     
         19 . The settable spacer fluid of  claim 1 , wherein the settable spacer fluid additionally comprises a set accelerator. 
     
     
         20 . The settable spacer fluid of  claim 1 , wherein the settable spacer fluid additionally comprises a weighting agent.