Cementing spacers for improved well cementation

Abstract

A method of cementing a well using a cementing spacer. The method includes pumping a drilling fluid into a well. A cementing spacer is then pumped into the well to serve as a buffer between the drilling fluid and a cement. The cementing spacer includes substantially unviscosified water and a weighting agent. Cement is then pumped into the well to displace the cementing spacer and the drilling fluid to complete the cementing of the well.

What is claimed is:  
     
         1 . A method of cementing a well using a cementing spacer, the method comprising: 
 pumping a drilling fluid into a well;    pumping a cementing spacer into the well to displace the drilling fluid, the cementing spacer comprising substantially unviscosified water and a weighting agent; and    pumping cement into the well to displace the cementing spacer and the drilling fluid and to thereby complete the cementing of the well.    
     
     
         2 . The method of    claim 1   , wherein the weighting agent comprises barite.  
     
     
         3 . The method of    claim 1   , wherein the weighting agent comprises calcium carbonate.  
     
     
         4 . The method of    claim 1   , wherein the cementing spacer further comprises a friction reducing additive.  
     
     
         5 . The method of    claim 1   , wherein the cementing spacer further comprises a low density weighting agent.  
     
     
         6 . The method of    claim 5   , wherein the low density weighting agent comprises a selected volume of hollow glass spheres.  
     
     
         7 . The method of    claim 5   , wherein the low density weighting agent comprises a selected volume of ceramic spheres.  
     
     
         8 . The method of    claim 5   , wherein the low density weighting agent comprises a selected volume of foamed nitrogen.