Low temperature set retarded well cement compositions and methods
AssigneeHalliburton Company
InventorLance E. Brothers
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Abstract
Improved set retarded cement compositions for cementing subterranean zones in wells at low temperatures having excellent short term compressive strength development and methods of using such compositions are provided. The compositions are basically comprised of a hydraulic cement, water and a copolymer containing 2-acrylamido-2-methylpropane sulfonic acid in an amount in the range of from about 65 to about 85 mole percent and acrylic acid in an amount in the range of from about 15 to about 35 mole percent having an average molecular weight below about 5000.
Claims13
An improved method of cementing a subterranean zone penetrated by a well bore at temperatures below about 170.degree. F. comprising the steps of:
- preparing a set retarded cement composition comprising a hydraulic cement, water and a set retarding additive, said set retarding additive being comprised of a copolymer consisting essentially of 2-acrylamido-2-methylpropane sulfonic acid in an amount in the range of from about 65 to about 85 mole percent and acrylic acid in an amount in the range of from about 15 to about 35 mole percent and having an average molecular weight below about 5000;
- placing said cement composition into said subterranean zone by way of said well bore;
- and
- allowing said cement composition to set in said zone.
An improved method of cementing a subterranean zone penetrated by a well bore at temperatures below about 170.degree. F. comprising the steps of:
- preparing a pumpable set retarded cement composition comprising a Portland hydraulic cement, water, a set retarding additive and a fluid loss reducing additive, said set retarding additive being comprised of a copolymer consisting essentially of 2-acrylamido-2-methylpropane sulfonic acid in an amount in the range of from about 65 to about 85 mole percent and acrylic acid in an amount in the range of from about 15 to about 35 mole percent and having an average molecular weight below about 5000;
- pumping said cement composition into said subterranean zone by way of said well bore;
- and
- permitting said cement composition to set into a hard mass in said zone.
Dependencies are inferred from the claim text.