A method and apparatus for selectively connecting a first fluid communication region to a further fluid communication region are disclosed. The apparatus comprises an elongate housing, locatable in a wellbore, comprising a first end portion associated with a first fluid communication region; a sheath member axially slidable within the housing and biased towards the first end portion via at least one biasing element; and an elongate shuttle member axially slidable within the housing and slidably locatable in a sealed relationship or non-sealed relationship with the sheath member; wherein the biasing element provides a predetermined biasing force that determines a threshold pressure which must be exceeded by a fluid pressure in the first fluid communication region to permit axial movement of the sheath member away from the first fluid communication region or towards a further fluid communication region.

A system includes an upper section, having a first lateral end. The upper section has upper production tubing configured to be a conduit for production fluids, an upper electrical cable configured to transmit electricity, and a sub-surface safety valve fixed to the upper production tubing. The system further includes a lower section having a second lateral end, lower production tubing configured to be a conduit for the production fluids, a lower electrical cable configured to transmit electricity, an electric submersible pump assembly, and an anchor configured to hold the lower section within the casing string. A stinger assembly is fixed to the first lateral end of the upper section, and a stinger receptacle is fixed to the second lateral end of the lower section. The stinger receptacle is configured to receive the stinger assembly and create an electrical connection between the upper section and the lower section.

Systems and methods for controlling downhole linear motors to minimize connections to surface equipment. In one embodiment, an ESP system is coupled by a power cable to equipment at the surface of a well. The ESP system includes a linear motor and a reciprocating pump. The motor has a set of position sensors that sense the position of a mover in the motor. Combining circuitry (E.G., XOR gate) combines the outputs of the position sensors into a single composite signal in which signal components corresponding to the position sensors are indistinguishable. A single channel carries the composite signal from the ESP system to the surface equipment. A control system determines a starting position of the motor and determines its subsequent position based on transitions in the composite signal. The motor is then operated based on the position determined from the composite signal.

Embodiments are disclosed for the control of downhole pumping systems that can perform a controlled draining operation of the downhole pumping system in the event of an interruption of a drive. Such embodiments include a zero power factor control, a motor braking, and a pumping down operation. The apparatus and the methods disclosed can include an independent piece of equipment interlocked with a variable speed drive, and installed at the primary or secondary of the step-up transformer where used. However, integration within other pieces of equipment, in particular the variable speed drive, and its control by the latter is also contemplated. Also disclosed is a transformer having a tap changer that includes a plurality of taps and contacts including shorting contacts, open contacts and auxiliary contacts.

This disclosure relates to an electric submersible pump assembly to measure a density of a fluid in a wellbore. The ESP assembly includes a density meter having a diffuser with an interior volume defined by an inner surface, a rotatable rotor arranged in the interior volume, a measurement channel, and a sensor sub-assembly configured to measure pressures in the measurement channel. The rotor includes a rotor channel defined by a first face of a partition of the rotor and an interior wall of the rotor, extends from an inlet to an outlet. The inlet is arranged at a first radial distance from an axis and the outlet is arranged at a second radial distance from the axis, greater than the first radial distance. The measurement channel, defined by the inner surface of the diffuser and a second face of the partition, extends from the outlet to the inlet.

Pumping of wellbore fluid to a surface may have a detrimental effect on the pump performance due to high gas concentrations in the fluid. A pump system that utilizes a helix gas separator provides greater pump efficiency by effectively removing the gas phase of the fluid. The wellbore fluid received at a pump system is directed from an intake to a gas separator that utilizes a stationary auger. The stationary auger induces rotational motion of the wellbore fluid causing the wellbore fluid to separate into a gas phase and a liquid phase. The stationary auger utilizes a tapered diameter and an opening between one or more helixes or vanes to separate a gas phase more efficiently from a liquid phase of a fluid.

The present invention relates to electric submersible pumps that have two or more permanent magnet motors and more specifically to such systems wherein permanent magnet motors are aligned using phase and pole alignment marks.

A method for making a wet mate electrical connection in an underground borehole with a static downhole conductor pin that is protected from the borehole environment by a non-sealed shuttle and a moveable mating receptacle/conductor which presses on the outer body of the shuttle thus causing it to move along the conductor pin tube. The conductor pin inserts into the receptacle connector and connects to the contacts. Both connectors are filled with a dielectric fluid for isolation and are pressure balanced to counteract volume variation due to temperature changes. The moveable receptacle connector uses a non-conductive pin which is replaced by the conductor pin and provides a surface for wiper seals. As mating occurs, the conductor pin replaces the non-conductive pin, so no volume change occurs, and pressure change is eliminated. A reverse labyrinth isolates the heavy dielectric of the static connector from borehole fluid.

An electric submersible pump (ESP) power cable. The ESP power cable has a first plurality of electric conductors encased in a first protective armor wherein a first void area is defined between the first plurality of electric conductors and the first protective armor, has a second plurality of electric conductors encased in a second protective armor wherein a second void area is defined between the second plurality of electric conductors and the second protective armor and wherein each one of the second plurality of electric conductors is spliced to a corresponding one of the first plurality of electric conductors, has a first filler positioned at least partially in the first void area, and comprises a second filler positioned at least partially in the second void area.

A technique facilitates deployment and operation of a pumping system, e.g. an electric submersible pumping system, in a borehole. A locking and sealing mechanism, e.g. a spring-loaded locking sealing mechanism, may be coupled with the pumping system and comprises an anchoring section along with a sealing section. The locking sealing mechanism may be constructed for deployment with the pumping system via a running tool. Once in position downhole, the anchoring section and the sealing section may be actuated into sealing engagement with the interior surface of a surrounding tubing. At this stage, production of a desired fluid may be accomplished by operating the pumping system.