Lightened cement grout suitable for the cementation of hydrocarbon production wells
AssigneesTotal Compagnie Francaise des Petroles, Ciments d'Origny
InventorsDaniel Baffreau, Jean-Claude Laugerotte, Nicolas Musikas
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Abstract
This invention relates to a lightened gas-impermeable cement grout which comprises hydraulic cement, water, silica fumes in an amount of from about 5 to about 65 weight % based on the weight of the cement, and at least one polyethylene imine having a molecular weight of between about 600,000 and about 1,000,000 in an amount of from about 1 to about 25% weight % based on the weight of the water.
Claims28
A lightened, gas-impermeable cement grout which comprises hydraulic cement, water, silica fumes in an amount of from about 5 to about 65 weight % based on the weight of the cement, and at least one polyethylene imine having a molecular weight of between about 600,000 and about 1,000,000 in an amount of from about 1 to about 25% weight % based on the weight of the water.
A process for preparing a lightened, gas-impermeable cement grout comprising hydraulic cement, water, silica fumes and at least one polyethylene imine, comprising the following steps in succession:
- a) combining the at least one polyethylene imine with the water, wherein the at least one polyethylene imine has a molecular weight of between about 600,000 and about 1,000,000 and is used in an amount of from about 1 to about 25 weight % of the weight of the water, to form a water/polyethylene imine mixture;
- b) adding the silica fumes to the water/polyethylene imine mixture to form a suspension;
- c) mixing a hydraulic cement into the suspension,
- wherein the silica fumes are added in an amount of from about 5 to about 65 weight % based on the weight of the hydraulic cement.
A process for cementation of a hydrocarbon well comprising injecting a lightened, gas-impermeable cement grout into the well at the periphery of tubes of the well and over at least one portion of the length of the tubes, between the tubes and adjoining group,
- said cement grout comprising hydraulic cement, water, silica fumes in an amount of from about 5 to about 65 weight % based on the weight of the cement, and at least one polyethylene imine having a molecular weight of between about 600,000 and about 1,000,000 in an amount of from about 1 to about 25% weight % based on the weight of the water.
Dependencies are inferred from the claim text.