Fly ash cementing compositions and methods
AssigneeHalliburton Company
InventorsDavid D. Onan, Dralen T. Terry, Bobby G. Brake
Life of this patent
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Abstract
The present invention provides fly ash cementing compositions and methods which are useful in any cementing application, and are particularly suitable for cementing in subterranean zones penetrated by well bores. The cementing compositions can include a portion of the drilling fluid used to drill a well bore as a component thereof. Also, drilling fluid can be disposed of by combining it with the fly ash cementing composition whereby it solidifies in a disposal location.
Claims24
A cementing composition comprising:
- a cement component consisting essentially of a fine particle size ASTM Class C fly ash or the equivalent fly ash wherein the particles are of a size no greater than about 36 microns and have a specific surface area no less than about 1.1 square meters per cubic centimeter;
- and
- sufficient water to form a slurry.
A fine particle size cementing composition for cementing in a subterranean zone penetrated by a well bore comprising:
- a fine particle size ASTM Class C fly ash or the equivalent fly ash wherein the particles are of a size no greater than about 36 microns and have a specific surface area no less than about 1.1 square meters per cubic centimeter;
- a dispersing agent comprised of the condensation polymer product of acetone, formaldehyde and sodium sulfite present in said composition in an amount in the range of from about 0.25% to about 1% by weight of said fly ash in said composition;
- a drilling fluid selected from the group consisting of a water base gel drilling fluid and a hydrocarbon base drilling fluid present in said composition in an amount in the range of from about 10% to about 50% by weight of said composition;
- and
- sufficient water to form a pumpable slurry.
A method of forming a hard substantially impermeable cementitious mass in a desired location comprising the steps of:
- placing a cementing composition in said location comprised of a cement component consisting essentially of a fine particle size ASTM Class C fly ash or the equivalent fly ash wherein the particles are of a size no greater than about 36 microns and have a specific surface area no less than about 1.1 square meters per cubic centimeter and sufficient water to form a slurry;
- and
- allowing said cementing composition to set into a hard substantially impermeable mass.
A method of cementing in a subterranean zone penetrated by a well bore comprising the steps of:
- pumping a cementing composition into said zone comprised of a fine particle size ASTM Class C fly ash or the equivalent fly ash wherein the particles are of a size no greater than about 36 microns and have a specific surface area no less than about 1.1 square meters per cubic centimeter, a dispersing agent comprised of the condensation polymer product of acetone, formaldehyde and sodium sulfite present in an amount in the range of from about 0.25% to about 1% by weight of said fly ash in said composition, a drilling fluid selected from the group consisting of a water base gel drilling fluid and a hydrocarbon base drilling fluid present in said composition in an amount in the range of from about 10% to about 50% by weight of said composition, and sufficient water to form a pumpable slurry;
- and
- allowing said cementing composition to set into a hard substantially impermeable mass in said zone.
A method of cementing a well with a cementing composition utilizing a portion of the drilling fluid used to drill the well as a component of the cementing composition comprising the steps of:
- forming a cementing composition comprised of a fine particle size ASTM Class C fly ash or the equivalent fly ash wherein the particles are of a size no greater than about 36 microns and have a specific surface area no less than about 1.1 square meters per cubic centimeter, a dispersing agent comprised of the condensation polymer product of acetone, formaldehyde and sodium sulfite present in an amount in the range of from about 0.25% to about 1% by weight of said fly ash, a drilling fluid selected from the group consisting of a water base gel drilling fluid and a hydrocarbon base drilling fluid present in an amount in the range of from about 10% to about 50% by weight of said composition and sufficient water to form a pumpable slurry;
- introducing the resulting cementing composition into said well;
- and
- permitting said composition to set into a hard mass in said well.
Dependencies are inferred from the claim text.