Abstract: A variable displacement reciprocating pump with pumping rate that is adjustable from zero to maximum stroke while the pump is running. Stroke is varied by changing relative position of pairs of eccentric inner and outer cams that drive the pump's plungers. The pump's input drive shaft drives two gear trains: a first gear train that turns the inner cams and a second gear train that turns the outer cams. These cams normally revolve together with no relative motion occurring between them. A rotary actuator is positioned in the first gear train to rotate the inner cams relative to the outer cams and thereby changes the pump's stroke. A computerized system of sensors and control valves allows the pump to be automatically controlled or limited to any one or combination of desired output flow, pressure and horsepower.

Abstract: A cement mixing method and apparatus for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A cement mixing method and apparatus for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A cement mixing method for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A cement mixing method for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A cement mixing method for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A variable displacement reciprocating pump with pumping rate that is adjustable from zero to maximum stroke while the pump is running. Stroke is varied by changing relative position of pairs of eccentric inner and outer cams that drive the pump's plungers. The pump's input drive shaft drives two gear trains: a first gear train that turns the inner cams and a second gear train that turns the outer cams. These cams normally revolve together with no relative motion occurring between them. A rotary actuator is positioned in the first gear train to rotate the inner cams relative to the outer cams and thereby changes the pump's stroke. A computerized system of sensors and control valves allows the pump to be automatically controlled or limited to any one or combination of desired output flow, pressure and horsepower.

Abstract: A variable displacement reciprocating pump with pumping rate that is adjustable from zero to maximum stroke while the pump is running. Stroke is varied by changing relative position of pairs of eccentric inner and outer cams that drive the pump's plungers. The pump's input drive shaft drives two gear trains: a first gear train that turns the inner cams and a second gear train that turns the outer cams. These cams normally revolve together with no relative motion occurring between them. A rotary actuator is positioned in the first gear train to rotate the inner cams relative to the outer cams and thereby changes the pump's stroke. A computerized system of sensors and control valves allows the pump to be automatically controlled or limited to any one or combination of desired output flow, pressure and horsepower.

Abstract: A method for determining absolute density of a slurry that typically contains entrained air, such as cement slurry, in a continuous mixing operation such those used in cementing a gas or oil well. The method obtains density measurements of a slurry at two different pressures and then uses the two density measurements and the two pressure measurements to compute absolute density of the slurry employing the following formula at isothermal conditions: Dabs=D1/(1?((D1/D2?1)/(P1/P2?1))), where Dabs=absolute density, D1=first density, D2=second density, P1=absolute pressure at which the first density was measured, and P2=absolute pressure at which the second density was measured.

Abstract: A method for determining absolute density of a slurry that typically contains entrained air, such as cement slurry, in a continuous mixing operation such those used in cementing a gas or oil well. The method obtains density measurements of a slurry at two different pressures and then uses the two density measurements and the two pressure measurements to compute absolute density of the slurry employing the following formula at isothermal conditions: Dabs=D1/(1?((D1/D2?1)/(P1/P2?1))), where Dabs=absolute density, D1=first density, D2=second density, P1=absolute pressure at which the first density was measured, and P2=absolute pressure at which the second density was measured.

Abstract: A gel mixing system that employs a dynamic diffuser for quickly removing the air from the fluid as the fluid exits a traditional gel mixer and employs progressive dilution of the gel in a series of hydration tanks to maximize hydration time without allowing the gel to become so viscous that it is not easily diluted or pumped. High shear agitation of the fluid between the hydration tanks helps to increase the hydration rate. Progressive dilution of the gel increases residence time of the gel in the tanks and results in longer hydration time in the limited tank space available, resulting in continuous production of gel that is almost fully hydrated when it is pumped to the fracturing blender and subsequently to the well bore without the need for an increase in the volume of the hydration tanks.

Abstract: A cement mixing method for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jet and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber. The five annular recirculation jets are located in alternating longitudinal alignment within the mixing chamber relative to the five annular water jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A cement mixing method for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.

Abstract: A flow through pressure transducer for use in harsh environments like oil well cement slurry mixing process. A thin cylindrical sensor sleeve is protected from fluid wear and corrosion by a molded elastomeric sleeve provided on its internal diameter that prevents fluid from reaching the sensor sleeve. Pressure is transmitted to the sensor sleeve through the elastomeric sleeve. The sensor sleeve is mounted in such a way that the fluid pressure only exerts hoop stresses on the sensor sleeve. Two dual strain gauges are mounted on the outside of the sensor sleeve in spaced apart relationship for measuring hoop stress and an additional strain gauge is mounted 90 degrees to the stress direction for temperature compensation. The body or spool of the transducer surrounds and protects the sensor sleeve and prevents leakage in the event of sleeve failure. The spool is held in between transducer outer flanges by threaded fasteners.

Abstract: A gel mixing system that employs a dynamic diffuser for quickly removing the air from the fluid as the fluid exits a traditional gel mixer and employs progressive dilution of the gel in a series of hydration tanks to maximize hydration time without allowing the gel to become so viscous that it is not easily diluted or pumped. High shear agitation of the fluid between the hydration tanks helps to increase the hydration rate. Progressive dilution of the gel increases residence time of the gel in the tanks and results in longer hydration time in the limited tank space available, resulting in continuous production of gel that is almost fully hydrated when it is pumped to the fracturing blender and subsequently to the well bore without the need for an increase in the volume of the hydration tanks.

Abstract: A method for determining absolute density of a slurry that typically contains entrained air, such as cement slurry, in a continuous mixing operation such those used in cementing a gas or oil well. The method obtains density measurements of a slurry at two different pressures and then uses the two density measurements and the two pressure measurements to compute absolute density of the slurry employing the following formula at isothermal conditions: Dabs=D1/(1?((D1/D2?1)/(P1/P2?1))), where Dabs=absolute density, D1=first density, D2=second density, P1=absolute pressure at which the first density was measured, and P2=absolute pressure at which the second density was measured.

Abstract: A method for determining absolute density of a slurry that typically contains entrained air, such as cement slurry, in a continuous mixing operation such those used in cementing a gas or oil well. The method obtains density measurements of a slurry at two different pressures and then uses the two density measurements and the two pressure measurements to compute absolute density of the slurry employing the following formula at isothermal conditions: Dabs=D1/(1?((D1/D2?1)/(P1/P2?1))), where Dabs=absolute density, D1=first density, D2=second density, P1=absolute pressure at which the first density was measured, and P2=absolute pressure at which the second density was measured.

Abstract: A hydration tank provided with an interior rotating vessel located between a stationary wall of the hydration tank and a stationary wall of a central inlet tube provided centrally within the tank. Liquid flows downward into the tank via a central inlet tube, then upward between the inlet tube and the rotating vessel, and then again downward between the rotating vessel and the tank wall to the exit. Horizontal vanes are provided on both the inside and outside of the rotating vessel that interleaf with horizontally extending stationary vanes provided on the wall of the tank and the central inlet tube. Together, the stationary and rotating vanes constantly mix the liquid in a direction that is normal to the direction of flow of the liquid without interfering with flow of the liquid through the tank.

Abstract: An automatically adjusting jet mixer used in mixing fracturing fluid gel for gas and oil wells. The mixer has an inner nozzle and an attached piston that move axially within the mixer's housing to change the size of the nozzle opening thorough which mix water enters the mixer. One side of the piston has a pressure regulated area and an opposite side has an upstream area. The upstream area is connected to the mix water supply pump and the pressure regulated area is connected to the outlet of a pressure regulator that maintains a constant pressure in the pressure regulated area. The piston and the nozzle move via hydraulic pressure exerted on the piston in proportion to the change in pressure in the upstream area to a position that will maintain a constant mixing jet pressure, thus providing constant specific mixing energy, i.e. constant energy per unit mass of fluid.

Abstract: A metering valve for metering dry powder material such as cement. The interior of the valve housing is expanded outward beginning at the sealing surface or lip located adjacent to the inlet opening, thereby forming an enlarged gap between the valve sleeve and housing to discourage powder accumulation in the gap and interference of large bulk particles and foreign materials with the sleeve and housing. An eccentric intermediate sleeve aligns the valve sleeve relative to the housing prior to rotation of the valve sleeve by either moving the valve sleeve away from or toward the valve inlet. The valve sleeve has a rubberized layer to seal with the housing's sealing surface or lip. A sleeve shield blocks entry of powder into the mouths of the vacuum breakers to prevent plugging of the vacuum breakers. Ball bearings are employed to suspend the valve sleeve within the housing, making the valve sleeve easier to rotate.