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US 5,311,944 AGranted
Blast furnace slag blend in cement
AssigneeShell Oil Company
InventorsKenneth M. Cowan, Arthur H. Hale
Life of this patent
Estimating the term…
Abstract
A cementitious slurry comprising microfine ground blast furnace slag and normally ground blast furnace slag. A microfine ground blast furnace slag is made of composition having a blaine specific surface area between 8,000 and 20,000 cm.sup.2 /g. By normally ground is meant slag compositions having a surface area of less than 8,000 cm.sup.2 /g. Such cementitious compositions have utility in construction, road building, and cementing wellbores.
Claims14
A method for drilling and cementing a well comprising:
- combining a drilling fluid and a blend of microfine ground blast furnace slag and normally ground blast furnace slag to produce a universal fluid;
- thereafter utilizing said universal fluid in a well drilling operation to form a borehole, thus producing a used universal fluid;
- thereafter combining an additional amount of a blend of microfine ground blast furnace slag and normally ground blast furnace slag, and an activator with said used universal fluid;
- disposing a pipe in said borehole;
- passing said cementitious slurry down said pipe and up into an annulus formed by said borehole and said pipe.
2 more elements
A method for drilling and cementing a well, comprising:
- (a) utilizing a blast furnace slag-containing drilling fluid in a well drilling operation to form a borehole with drill string having a hollow pipe, thus laying down a filter cake on walls of said borehole,
- (b) passing an activator-containing fluid down said hollow pipe and up into contact with said filter cake, to cause said filter cake to harden
- (c) displacing said activator-containing fluid with a drilling fluid and continuing said drilling operation thus producing a used drilling fluid,
- (d) removing said drill string and inserting a casing,
- (e) combining an activator system and a blend of minor amount of microfine ground blast furnace slag and a major amount of normally ground blast furnace slag with said used drilling fluid thus producing a cementitious slurry, and
- (f) passing said cementitious slurry down said casing and up into an annulus surrounding said casing.
3 more elements
Dependencies are inferred from the claim text.