Cement compositions for cementing wells, allowing pressure gas-channeling in the cemented annulus to be controlled
AssigneeEtudes et Fabrication Dowell Schlumberger
InventorsPhilippe A. Parcevaux, Bernard M. Piot, Claude J. Vercaemer
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Abstract
The invention relates to cement compositions for cementing wells, which allow pressure gas-channeling to be effectively controlled up to more than about 485.degree. F. The cement composition contains a styrene-butadiene latex and a stabilizer. The film of latex interrupts gas-channeling after an extremely brief path.
Claims17
Cement slurry compositions for cementing oil wells having improved properties of the cement and inhibiting pressure gas channeling in the cemented annulus, even at high temperature, said composition consisting essentially of a hydraulic cement, about 5-30% by weight of cement of a compatible styrene (70-30 weight percent)/butadiene (30-70 weight percent) copolymer latex, about 1-20% by weight of latex of a latex stabilizer selected from the group consisting of
- lignosulfonates and their partly desulfonated derivatives
- sulfonic acid or sulfite modified melamine-formaldehyde resins
- formaldehyde/sulfonate naphthalene resins, and
- condensation products of bi-nuclear sulfonated phenols and of formaldehyde
- and water in an amount such that the total fluid content of water, latex and stabilizer is about 30-70% by weight of cement.
Dependencies are inferred from the claim text.