Back to results
US 4,767,460 AGranted
Cement compositions for cementing of wells enabling gas channelling in the cemented annulus to be inhibited by right-angle setting
AssigneeDowell Schlumberger Incorporated
InventorsP. Parcevaux, B. Piot, P. Sault
Life of this patent
Estimating the term…
Abstract
The cement compositions according to the invention are designed for cementing wells, in particular oil and gas or geothermal wells, and for withstanding very high temperatures. A combination of styrene-butadiene latex and a polyoxyethylenated nonylphenol stabilizer of this latex is provided. Cement sets at a right angle and gas migration in the annulus is prevented.
Claims8
An aqueous cement slurry composition for cementing oil, gas, and geothermal wells, comprising:
- cement, water and about 0.5 to 2% by weight of cement of an ammonium salt of a sulfated nonylphenoxypoly(ethyleneoxy) ethanol to produce an aqueous cement slurry having a right-angle set property,
- said right-angle set property permitting said aqueous cement slurry to go directly from a state where hydrostatic pressure of said aqueous cement slurry is transmitted by a slurry column directly to a state where gas migration is effectively prevented by setting of said cement.
Dependencies are inferred from the claim text.