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US 12,577,449 B2Granted
Compositions and methods for well cementing
AssigneeSchlumberger Technology Corporation
InventorsBipin Jain, Shameed Ashraf
Life of this patent
Estimating the term…
Abstract
The effectiveness of expansive cement systems may be diluted when, during a well cementing operation, commingling takes place between the cement slurry and a spacer fluid, a drilling fluid, or both. Incorporating expansive agents in the spacer fluid or drilling fluid may reduce or negate the loss of expansion at the cement slurry/spacer interface or the cement slurry/drilling fluid interface, thereby promoting zonal isolation throughout the cemented interval.
Claims18
A method, comprising:
- preparing a drilling fluid comprising a non-aqueous fluid and an expanding agent comprising calcium oxide or calcined magnesium oxide or both, wherein the expanding agent is suspended in a non-aqueous liquid comprising a dispersant;
- during a cementing operation in a well, placing the drilling fluid and a cement slurry in the well such that the drilling fluid flows ahead of the cement slurry;
- placing a spacer fluid between the drilling fluid and the cement slurry, the spacer fluid commingling with the drilling fluid and the cement slurry to form an interface;
- and
- curing the cement slurry and the interface, wherein the interface expands or does not shrink upon the curing.
2 more elements
Dependencies are inferred from the claim text.