Thixotropic cementing compositions
AssigneeHalliburton Company
InventorsGabriel W. Ostroot, Jiten Chatterji
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Abstract
A thixotropic cementing composition for use in oil and gas wells comprises a hydraulic cement slurry including as an additive a complex reaction product of a water soluble carboxyalkyl, hydroxyalkyl or mixed carboxyalkyl hydroxyalkyl ether of cellulose, and a polyvalent metal salt, for example a reaction product of hydroxyethylcellulose and zirconyl chloride.
Claims25
A thixotropic slurry for cementing oil and gas wells and the like, comprising portland cement and a complex formed by the reaction of zirconyl chloride with hydroxyethyl cellulose, the slurry being characterized by having a viscosity in the range from about 5 to 30 poises when agitated and in the range from 50 to 200 poises when quiescent.
A dry mixture of a hydraulic cement with from about 0.1% to about 0.75% of hydroxyethyl cellulose and from about 0.1% to about 3.0% of zirconyl chloride, the percentages being by weight of the cement.
A thixotropic cement slurry having a relatively high viscosity under quiescent conditions and low viscosity under turbulent conditions, comprising a mixture of water, hydraulic cement and a thixotropic agent formed by complexing a polyvalent metal salt selected from the group consisting of zirconium, lead, chromium, ferric iron, hafnium, lanthanum and yttrium and a water soluble cellulose ether selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxyethyl carboxymethyl cellulose or combinations thereof.
An additive which provides thixotropic properties of relatively high viscosity under quiescent conditions and low viscosity under turbulent conditions comprising a complex of a polyvalent metal selected from zirconium, lead, chromium, ferric iron, hafnium, lanthanum and yttrium complexed under alkaline cement conditions with a water soluble cellulose ether selected from hydroxyalkyl cellulose, carboxyalkyl cellulose ethers, mixed ethers and combinations thereof.
A thixotropic cement slurry having a relatively high viscosity under quiescent conditions and low viscosity under turbulent conditions, comprising a mixture of water, hydraulic cement and a thixotropic agent formed by complexing a polyvalent metal salt selected from the group consisting of zirconium, lead, chromium, ferric iron, hafnium, lanthanum and yttrium and a water soluble hydroxyethyl cellulose.
A thixotropic cement slurry having a relatively high viscosity under quiescent conditions and low viscosity under turbulent conditions comprising a mixture of water, hydraulic cement and a thixotropic agent formed by complexing zirconyl chloride and a water soluble cellulose ether selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxyethyl carboxymethyl cellulose or combinations thereof.
Dependencies are inferred from the claim text.