Method of using thixotropic cements for combating gas migration problems
AssigneeHalliburton Company
InventorsFred Sabins, Jerry D. Childs
Life of this patent
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Abstract
A thixotropic cement composition comprising water, hydraulic cement, a titanium chelate and a crosslinkable agent and methods of using same to combat migration of formation fluids in oil, gas and water wells are provided.
Claims15
A method for cementing a zone under pressure comprising pumping a thixotropic cement slurry into said zone, terminating pumping, and allowing said static slurry to set, wherein said slurry comprises water, hydraulic cement, a crosslinking agent selected from the group consisting of titanium chelates and a crosslinkable agent selected from the group consisting of water-soluble cellulose ethers;
- polyvinyl alcohol;
- homopolymers, copolymers and terpolymers of AMPS (2-acrylamido-2-methylpropane sulfonic acid), sodium vinylsulfonate, acrylamide N,N-dimethylacrylamide and acrylic acid;
- and mixtures thereof, whereby said slurry develops static gel strength in an amount sufficient to prevent fluid migration during some time after the pumping has terminated and until the cement slurry has set.
A method of combating annular gas and fluid migration during cementing of the annular space between the casing and the formation wall of an oil or gas well or the like comprising pumping a thixotropic cement slurry into said space, terminating pumping, and allowing said slurry to set, wherein said slurry comprises water, hydraulic cement, and amounts of titanium monotriethanolamine and carboxymethylhydroxyethyl cellulose in an amount sufficient to prevent fluid migration during some time after the pumping has terminated and until the cement slurry has set.
Dependencies are inferred from the claim text.