Standard Oil Company (indiana)

The Standard Oil Company

Charles A Powers

George B Holman

Robert C Smith

A diverter tool and method of use thereof for use in setting a cement plug in a well. The tool comprises a hollow cylindrical body provided with a plurality cylindrical ports, the axes of which form a plane essentially perpendicular to the axis of the tool.

Diverter tool and its use

A 9 to 12 ppg (1.08 to 1.4 kg/liter) cement slurry for use in oil well type completions which comprises hydraulic cement about 10 to about 30 weight percent hollow glass microspheres based on the weight of the cement and sufficient water to form a pumpable slurry with an API free water content of no more than about 2 volume percent. This slurry is preferably mixed with an amount of water required to produce a slurry with the hydraulic cement having at least an API minimum water content and an API free water content of no more than about 2 volume percent and an additional amount of water equal to about 1.3 to about 1.8 weight percent water based on the weight of the hydraulic cement for each weight percent of the microspheres. The microspheres have true particle densities of at least 0.2 gm/cm.sup.3, hydrostatic collapse strengths of at least 500 psi (3447 kPa) and average particle diameters of less than about 500 microns.

Low density cement slurry and its use

A 9 to 12 ppg (1.08 to 1.4 kg/liter) cement slurry for use in oil well type completions which comprises hydraulic cement about 10 to about 30 weight percent hollow glass microspheres based on the weight of the cement and sufficient water to form a pumpable slurry with an API free water content of no more than about 2 volume percent. This slurry is preferably mixed with an amount of water required to produce a slurry with the hydraulic cement having at least an API minimum water content and an API free water content of no more than about 2 volume percent and an additional amount of water equal to about 1.3 to about 1.8 weight percent water based on the weight of the hydraulic cement for each weight percent of the microspheres. The microspheres have true particle densities of about 0.2 to about 0.5 gm/cm.sup.3, hydrostatic collapse strengths of at least 500 psi (3447 kPa) and average particle diameters of less than about 500 microns.

A process for reducing the waiting-on-cement (WOC) time associated with the cementing of a casing string in an oil well involving the specific improvement of pumping into the well a highly retarded cement slurry containing a dispersed encapsulated accelerator, such as calcium chloride or anhydrous sodium metasilicate, wherein the encapsulating material is specifically selected such that it will melt at a temperature above the bottom-hole circulating temperature but below the bottomhole static temperature of the well to be cemented. Petroleum-derived waxes and petroleum-derived waxes in combination with vinyl resins, such as wax-compatible copolymers of ethylene and vinyl acetate, are particularly suitable as the meltable encapsulating material exhibiting excellent strength and abrasion resistance as well as serving as a moisture barrier. The improved process is particularly useful in cementing deep hot wells.

Growing community of inventors

Tulsa, OK, United States of America

Charles A Powers