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US 11,920,079 B2Granted
Compositions and methods for well cementing
AssigneeSchlumberger Technology Corporation
InventorsBipin Jain, Shameed Ashraf
Life of this patent
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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.
Claims9
A method, comprising:
- (a) preparing a composition comprising an aqueous cement slurry and a non-aqueous additive comprising a suspension of an expanding agent comprising calcium oxide, calcined magnesium oxide, or both;
- (b) during a well cementing operation, placing the cement slurry in the well such that the cement slurry flows behind a spacer fluid or a drilling fluid, or both;
- (c) causing the spacer fluid or the drilling fluid to commingle with the cement slurry, thereby forming an interface;
- and
- (d) curing the cement slurry and the interface, wherein the interface expands or does not shrink upon the curing;
- wherein the non-aqueous additive further comprises an emulsifier comprising polysorbates or sorbitan esters, or both;
- wherein the emulsifier is present in the non-aqueous additive at a concentration between 0.01 wt % and 10 wt %.
4 more elements
Dependencies are inferred from the claim text.