Wellsite Intelligence with the PCP Solution

The PCP solution uses the Weatherford VFD, a vector flux drive (VFD) that provides infinite speed control with constant torque control throughout the speed range. The VFD can be used by itself or coupled with downhole gauges for more defined control. An intelligent remote terminal unit (RTU) can add data logging capability for finer resolution in data capture.

Vector Flux Drive (VFD)

Weatherford's PCP solution uses the Weatherford vector flux drive(VFD) that provides infinite speed control with constant torque control throughout the speed range.

The VFD provides a system that offers equipment protection while operating in dynamic conditions such as water floods or high sand cut. The VFD constantly monitors the rod string torque and automatically adjusts the power output to ensure the system does not exceed user set limits. Internal programming makes online decisions to safely handle accumulations of solids in the produced fluids, sudden water slugs, and other short-term conditions where the operator does not want the well to shut down.

Operating costs can be reduced by limiting startup current, rescheduling chemical treatments, and limiting the stress on mechanical

The VFD comes in a NEMA 3R sealed enclosure. This keeps outside air from entering the box and consequentially shortening the life span of the unit.

The VFD provides the following benefits:

• Total speed control
• Total torque control
• Integral RTU
• Specific programming for lift application

Downhole Sensors

Weatherford's downhole sensors provide reliable pressure and temperature readings. All of Weatherford's sensors are manufactured with the highest quality standards to assure stability and longevity in the harsh downhole environment. The use of high pressure metal-to-metal seals and elastomer backup assures long term reliability. The sensors are built with compact designs to fit most applications including slim holes. The sensors offer high level accuracy in a cost efficient design.

The sensors are used with controllers and the VFDs to provide more accurate control on the well based on the changing downhole conditions. In addition, these sensors are used to evaluate reservoir conditions.

Weatherford provides analog sensors for continuous transmission which are ideal for single point monitoring such as intake pressure and temperature. Digital sensors offer addressable transmission which gives you the ability to multi-drop additional sensors on a single conductor I-line so that you can monitor both intake, discharge pressure, and temperature.

VFD with Downhole Sensors

The VFD can accommodate up to three analog input sensors for control. This would include one surface pressure sensor and two downhole sensors. This solution provides all the benefits of the VFD and the additional benefit of well optimization. The VFD uses the system torque and the pressure sensor inputs to provide accurate fluid level measurement with full mechanical safety.

VFD with one pressure sensor monitoring surface casing gas and another at the pump inlet can accurately determine fluid level. The information is used to automatically adjust the speed command of the VFD to achieve the required level.

With pressure sensors located at the inlet and outlet of the pump and monitoring casing gas pressure at surface, VFD accurately calculates the differential of pressure across the pump to assure that the pump is not over pressured. With this solution, clogged pump inlets which would cause an increase in annulus level, will initiate a speed decrease rather than speed increase and protect the pumping system.

PCP Overview
Wellsite Intelligence
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