Borehole cement slurry additive, method for storing same, borehole cement slurry, and borehole cementing method
AssigneeNissan Chemical Corporation
InventorsSatoru Murakami, Masaki Kimata, Isao Oota
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Abstract
A borehole cement slurry additive that is capable of suppressing the generation of free water from cement slurries in any environment, whether cold regions, mild regions, or hot regions; and a method for storing the same. The borehole cement slurry additive contains: an aqueous dispersion of silica having an average particle size of 3-200 nm as determined via dynamic light scattering; and a compound having an alcoholic hydroxyl group as a dispersion stabilizer, the compound being included in an amount of 1-30 mol per 1,000 g dispersion medium in the aqueous silica dispersion.
Claims11
An additive for cement slurry for a well, comprising:
- an aqueous dispersion of colloidal silica particles having an average particle size of 3 to 200 nm by a dynamic light scattering method;
- and
- a dispersion stabilizer consisting of at least one compound having an alcoholic hydroxyl group selected from the group consisting of methanol, ethanol, isopropyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, and glycerin, optionally in combination with a water-soluble primary, secondary or tertiary amine, wherein
- the additive for cement slurry for a well comprises 1 to 30 mol of the compound per 1000 g of a dispersion medium in the aqueous dispersion of the colloidal silica particles,
- in the case of retaining the additive for cement slurry for a well at −20° C. for 48 hours and subsequently measuring an average particle size by the dynamic light scattering method at +20° C., the average particle size falls within a range of 1.0 to 7.0 times the initial average particle size before the retention, and
- in the case of retaining the additive for cement slurry for a well at +50° C. for 7 days and subsequently measuring an average particle size by the dynamic light scattering method at +20° C., the average particle size falls within a range of 1.0 to 7.0 times the initial average particle size before the retention.
Dependencies are inferred from the claim text.