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US 5,361,842 AGranted
Drilling and cementing with blast furnace slag/silicate fluid
AssigneeShell Oil Company
InventorsArthur H. Hale, Kenneth M. Cowan
Life of this patent
Estimating the term…
Abstract
A drilling and cementing operation is carried out utilizing a universal fluid comprising blast furnace slag, water, a silicate and a retarder, the components of the drilling fluid being chosen so as to have a dual functionality in promoting the drilling fluid and thereafter in being functional constituents of a cementitious slurry.
Claims25
A method for drilling and cementing, comprising:
- drilling a wellbore with a drill string comprising a drill pipe utilizing a drilling fluid comprising water, blast furnace slag, a silicate and a retarder;
- circulating said drilling fluid down said drill pipe and up an annulus between said drill pipe and walls of said borehole, thus laying down a filter cake on said walls of said borehole during said drilling and producing a used drilling fluid and producing a used drilling fluid;
- withdrawing said drill string and inserting a pipe, thus creating an annulus between said pipe and said walls of said borehole;
- incorporating an activator system into a portion of said used drilling fluid to produce a cementitious slurry;
- and
- displacing said cementitious slurry into at least a portion of said annulus between said pipe and said walls of said borehole.
3 more elements
A method for drilling and cementing, comprising:
- drilling a wellbore utilizing a drilling fluid comprising water, sodium chloride, 10 to 80 lbs/bbl of blast furnace slag having a particle size such that it exhibits a surface area within the range of 4,000 cm.sup.2 /g to 9,000 cm.sup.2 /g, a synthetic polymer fluid loss control agent, starch, a welan gum biopolymer viscosifier, a water soluble carbohydrate polymer deflocculant, a sodium silicate viscosifier and shale stabilizer, bentonite, and barite;
- thereafter incorporating into said drilling fluid an activator system comprising a mixture of 2 to 6 lbs/bbl of sodium hydroxide in conjunction with 7 to 21 lbs/bbl of sodium carbonate and additional blast furnace slag in an amount sufficient to give a total blast furnace slag concentration in said cementitious slurry within the range of 100 to 300 lbs/bbl, to produce a cementitious slurry;
- and
- displacing said cementitious slurry into said wellbore to effect cementing and wherein said drilling fluid contains no partially hydrolyzed polyacrylamide or carboxymethyl cellulose.
1 more element
A method of drilling and cementing, comprising:
- drilling a wellbore with a drill string comprising a drill pipe utilizing a drilling fluid comprising water, blast furnace slag, a silicate and a retarder;
- circulating said drilling fluid down said drill pipe and up an annulus between said drill pipe and walls of said wellbore thus laying down a filter cake on said walls of said wellbore during said drilling thus producing a used drilling fluid, said wellbore being disposed in a formation having sufficient heat that heat is removed by said circulating of said drilling fluid;
- withdrawing said drill string and inserting a pipe, thus creating an annulus between said pipe and said walls of said borehole;
- adding additional blast furnace slag to said used drilling fluid to produce a cementitious slurry;
- and
- displacing said cementitious slurry into at least a portion of said annulus;
- and
- maintaining said cementitious slurry in said at least a portion of said annulus until said heat from said formation activates said cementitious slurry to thus cause said cementitious slurry to set into a cement.
5 more elements
Dependencies are inferred from the claim text.