Bj Services Company

The Western Company of North America

Robert L Dillenbeck

Bradley T Carlson

Murray J Rogers

Thomas Heinold

Harold Dean Brannon

Christopher John Stephenson

Dan Thomas Mueller

Windal Scott Bray

Virgilio C Go Boncan

Bobby E Hall

Dean S Porter

Scott G Nelson

A method of testing and a tester apparatus to determine the axial stress and strain of cements under the temperature and pressures encountered by cement during use in wellbore environments. Using these stress and strain measurements, the Young's Modulus may be established for a material at the encountered temperature and pressure of the wellbore. By combining static tensile strength testing and elasticity measurements of cements, Young's Modulus values for different cement compositions under stresses that are similar to the conditions occurring in an actual wellbore are possible.

Testing apparatus and method of deriving Young's modulus from tensile stress/strain relationships

An apparatus for use in circulating cement in a casing in a wellbore is described having a first component such as a sensor disposed on the casing and a second component such as a detectable device disposed at a fluid interface formed between the cement and a fluid. The sensor may be a sensor coil mounted on the perimeter of the lower end of the casing, while the detectable device may be a transponder capable of emitting Radio Frequency Identification signals to the sensor to signal its arrival at the lower end of the casing. The transponder may be encased in a protective covering. Also described is a method of cementing a casing utilizing a first component such as a sensor disposed on the casing and a second component such as a detectable device disposed in the cement.

Apparatus and method of detecting interfaces between well fluids

The storable, low-density, hydraulically-active, cementitious slurry of the invention is suitable for cementing within a subterranean formation for oil or gas wells. The low-density slurry comprises a hydraulically-active cementitious material, a set retarder, a plasticizer, glass or ceramic micro-spheres, and a strengthening agent. Further the slurry is substantially free of a suspension agent. The storable, low-density, hydraulically-active, cementitious slurry is made by adding glass or ceramic micro-spheres to a hydraulically-active cementitious material, adding a strengthening agent to the microsphere containing composition, and mixing the resulting composition with water, a set retarder, and a plasticizer to generate a slurry, wherein the set retarder is present in an amount sufficient to allow storage of the slurry.

Ultra low density cementitious slurries for use in cementing of oil and gas wells

Cement compositions including mixtures of substantially elastic material and cement that may be formulated exhibit reduced bulk volume shrinkage during curing as compared to conventional cement compositions. In one application, such cement compositions may be used for cementing in substantially closed system, such as the interior of a mold used for producing preformed concrete items.

Compositions and methods for cementing using elastic particles

An oil and gas well cementing composition and method are shown utilizing hydraulic cement, water a cement hydration retarder and an additive which is effective over a selected time period to degrade the retarder. The additive is a controlled release oxidizer which releases nascent oxygen over time to gradually oxidize the cement hydration retarder, thereby providing a single cement slurry design for cementing pipes for oil and gas wells where wide temperature differentials exist between the two ends of the pipe.

Method for controlling the set time of cement

A clay control additive for cement composition of the general formula: ##STR1## wherein the R groups are selected from a C.sub.1 to C.sub.4 substituted alkyl.

Growing community of inventors

Spring, TX, United States of America

Robert L Dillenbeck