Drilling fluid that when mixed with a cement composition enhances physical properties of the cement composition

Abstract

According to an embodiment, a drilling fluid comprises: water and a set accelerator, wherein the drilling fluid has a 10 minute gel strength of less than 20 lb*ft/100 sq ft, wherein the drilling fluid has a density in the range of about 9 to about 14 pounds per gallon, wherein the drilling fluid remains pourable for at least 5 days, and wherein when at least one part of the drilling fluid mixes with three parts of a cement composition consisting of water and cement, the drilling fluid cement composition mixture develops a compressive strength of at least 1,200 psi. According to another embodiment, a method of using the drilling fluid comprises the steps of: introducing the drilling fluid into at least a portion of a subterranean formation, wherein at least a portion of the drilling fluid is capable of mixing with a cement composition.

What is claimed is: 
     
         1 . A drilling fluid comprising:
 water and a set accelerator,
 wherein at least a portion of the drilling fluid is capable of mixing with a cement composition, and wherein a test mixture of the drilling fluid and a cement composition consisting of water and cement, having a drilling fluid to cement composition ratio of 1:3, develops a compressive strength of at least 1,200 psi; whereas, a substantially identical test mixture, except that the drilling fluid does not contain the set accelerator, develops a compressive strength of less than 1,200 psi. 
   
     
     
         2 . The drilling fluid according to  claim 1 , wherein the water is selected from the group consisting of freshwater, brackish water, saltwater, and any combination thereof. 
     
     
         3 . The drilling fluid according to  claim 1 , wherein the set accelerator is in at least a sufficient concentration such that the test mixture develops a compressive strength of at least 1,200 psi. 
     
     
         4 . The drilling fluid according to  claim 1 , wherein a test mixture of the drilling fluid and a cement composition consisting of water and cement, having a drilling fluid to cement composition ratio of 10:90, develops a compressive strength of at least 2,000 psi; whereas, a substantially identical test mixture, except that the drilling fluid does not contain the set accelerator, develops a compressive strength of less than 2,000 psi. 
     
     
         5 . The drilling fluid according to  claim 1 , wherein when at least one part of the drilling fluid mixes with three parts of a cement composition consisting of water and cement, the drilling fluid cement composition mixture develops a compressive strength of at least 1,200 psi. 
     
     
         6 . The drilling fluid according to  claim 1 , wherein the set accelerator is selected from the group consisting of sodium metasilicate, potassium orthosilicate, sodium orthosilicate, and combinations thereof. 
     
     
         7 . The drilling fluid according to  claim 1 , wherein the drilling fluid further comprises a viscosifier. 
     
     
         8 . The drilling fluid according to  claim 7 , wherein the viscosifier is selected from the group consisting of a xanthan gum polymer, cellulose, derivatives thereof, and any combinations thereof. 
     
     
         9 . The drilling fluid according to  claim 7 , wherein the viscosifier is in at least a sufficient concentration such that the drilling fluid has a 10 min gel strength of less than 20 lb*ft/100 sq ft. 
     
     
         10 . The drilling fluid according to  claim 1 , wherein the drilling fluid further comprises a weighting agent. 
     
     
         11 . The drilling fluid according to  claim 10 , wherein the weighting agent is selected from the group consisting of barite, hematite, manganese tetroxide, calcium carbonate, and combinations thereof. 
     
     
         12 . The drilling fluid according to  claim 10 , wherein the weighting agent is selected such that the drilling fluid has a 10 min gel strength of less than 20 lb*ft/100 sq ft. 
     
     
         13 . The drilling fluid according to  claim 10 , wherein the weighting agent is selected such that the drilling fluid remains in a fluid state for a specified period of time. 
     
     
         14 . The drilling fluid according to  claim 1 , wherein the drilling fluid further comprises a set retarder. 
     
     
         15 . The drilling fluid according to  claim 14 , wherein the set retarder is selected from the group consisting of a lignosulfonate, a lignite, a synthetic polymer, and combinations thereof. 
     
     
         16 . The drilling fluid according to  claim 14 , wherein the set retarder is in at least a sufficient concentration such that the drilling fluid has a 10 min gel strength of less than 20 lb*ft/100 sq ft. 
     
     
         17 . The drilling fluid according to  claim 1 , wherein the drilling fluid further comprises a dispersant. 
     
     
         18 . The drilling fluid according to  claim 17 , wherein the dispersant is selected from the group consisting of lignosulfonates, lignite, alcohol derivatives, and combinations thereof. 
     
     
         19 . The drilling fluid according to  claim 1 , wherein the drilling fluid does not contain a clay. 
     
     
         20 . The drilling fluid according to  claim 1 , wherein a mixture of the drilling fluid and the cement composition sets.