Retarded aqueous hydraulic cement slurry
AssigneeThe Dow Chemical Company
InventorsArthur S. Metcalf, Louis H. Eilers
Life of this patent
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Abstract
A retarded aqueous hydraulic cement slurry is provided containing, in addition to water and a hydraulic cement, a retarder selected from the group consisting of: (a) alkaline earth metal salts of mono- and di-carboxylic acid derivatives of simple sugars, (b) alkaline earth metal salts of borate esters of mono- and di-carboxylic acid derivatives of simple sugars, and (c) mixtures of any two or more of the foregoing. Unexpectedly, the retarder of the present invention is compatible with polyamine type fluid loss agents and with certain thixotropic cements. Also, the retarder is sufficiently water soluble so that it can be prepared as a liquid additive, thereby simplifying mixing procedures in remote locations such as offshore well platforms.
Claims17
A hydraulic cement slurry comprising a hydraulic cement, sufficient water to form a pumpable slurry which will cure to a dimensionally stable solid, and an effective amount of a retarder selected from the group consisting of
- alkaline earth metal salts of mono- and di-carboxylic acid derivatives of simple sugars,
- said slurry being substantially free of lignin derivatives.
A hydraulic cement slurry comprising a hydraulic cement;
- a polyamino fluid loss additive selected from the group consisting of polyalkyleneimines, polyalkylenepolyamines and mixtures thereof;
- a dispersant;
- water;
- and dissolved in the water, a retarder selected from the group consisting of (a) alkaline earth metal salts of mono- and di-carboxylic acid derivatives of simple sugars, and (b) alkaline earth metal salts of borate esters of mono- and di-carboxylic acid derivatives of simple sugars, and (c) mixtures of any of the foregoing.
A method for cementing a well comprising:
- providing a concentrated aqueous solution comprising at least one water soluble fluid loss additive;
- providing a concentrated aqueous solution comprising at least one water soluble retarder;
- providing a source of mix water;
- adding an effective amount of each of the concentrates to the mix water;
- pumping said mix water with said concentrates added thereto through a conduit connected to the well and having means for continuously admixing a dry particulate with the mix water;
- continuously adding an effective amount of dry particulate hydraulic cement to the mix water via said means in said conduit to form a pumpable cement slurry which will cure after emplacement adjacent a preselected zone in the well, and
- injecting the pumpable slurry into the well to a point adjacent the preselected zone, said slurry being further characterized as consisting of water and water-soluble components only, with the exception of the neat cement, and being substantially free of lignin derivatives.
Dependencies are inferred from the claim text.