Use of catalyst composition for cementing a wellbore and cement slurry for the same

Abstract

The present invention relates the use of acatalyst composition consisting of ammonium chloride, aluminum chloride, and magnesium oxide for addition to cement for oil well cementing. Moreover, the invention relates to a method of cementing a wellbore, comprising the steps of: i) drilling a wellbore; ii) introducing a casing string into the wellbore; iii) preparing a cement slurry based on a combination of cement and a catalyst composition consisting of ammonium chloride, aluminum chloride, and magnesium oxide; iv) pumping said cement slurry into the wellbore; and v) allowing said cement slurry to set. In addition, the invention relates to a cement slurry for cementing a wellbore, comprising i) cement, ii) water; and iii) a catalyst composition consisting of ammonium chloride, aluminum chloride, and magnesium oxide.

1 . Use of a catalyst composition consisting of I) ammonium chloride, II) aluminum chloride, and III) magnesium oxide for addition to cement for oil well cementing. 
     
     
         2 . Composition according to  claim 1 , wherein the total quantity of I) is 1 to 25% by weight, preferably 5 to 15% by weight, more preferably 8 to 13% by weight; based on the total weight of I)+II)+III). 
     
     
         3 . Composition according to  claim 1 , wherein the total quantity of II) is 10 to 50% by weight, preferably 20 to 40% by weight, more preferably 25 to 35% by weight, based on the total weight of I)+II)+III). 
     
     
         4 . Composition according to  claim 1 , wherein the total quantity of III) is 5 to 40% by weight, preferably 10 to 30% by weight, more preferably 15 to 25% by weight, based on the total weight of I)+II)+III). 
     
     
         5 . Method of cementing a wellbore, comprising the steps of: i) drilling a wellbore; ii) introducing a casing string into the wellbore; iii) preparing a cement slurry based on a combination of cement and a catalyst composition consisting of a) ammonium chloride, b) aluminum chloride, and c) magnesium oxide; iv) pumping said cement slurry into the wellbore; and v) allowing said cement slurry to set. 
     
     
         6 . Cement slurry for cementing a wellbore, comprising i) cement, ii) water; and iii) a catalyst composition consisting of I) ammonium chloride, II) aluminum chloride, and III) magnesium oxide. 
     
     
         7 . Cement slurry according to  claim 6 , comprising between 50 and 85 wt %, preferably between 65 and 75 wt % of I) cement, and between 20 and 40 wt %, preferably between 25 and 30 wt % of II) water, and between 0.1 and 10 wt %, preferably between 1 and 3 wt %, more preferably between 1.5 and 2.5 wt % of catalyst composition III).