Abstract:
An artificial lifting system is disclosed. The artificial lifting system comprises an elongated cylinder fixed to a base or ground. The elongated cylinder receives a piston rod axially movable therein. The piston rod engages a downhole rod pump for driving the rod pump reciprocating uphole and downhole to pump downhole fluid to the surface. A control unit controls the axial movement of the piston rod, and automatically adjust the system operation to adapt to drift of the top and bottom stop positions of the piston rod. In an alternative embodiment, the system further comprises a dump valve controlled by the control unit to prevent over-stroke. In another embodiment, the system further comprises a chemical injection unit for injecting treatment fluid to a wellbore under the control of the control unit.
Abstract:
A pump apparatus has a downhole pump disposed in a wellbore and has a motor at the surface, and a rod string operatively moved by the motor reciprocates the downhole pump in the wellbore. Downhole data indicative of load and position of the downhole pump is generated using surface measurements and a wave equation model having a damping factor. Actual fluid load lines are determined from the downhole data for upstrokes and downstrokes of the downhole pump, and calculated fluid load lines for from the strokes are determined from the distribution of the load values in the downhole data. The actual fluid load lines are compared to the calculated fluid load lines to determine if the downhole data is over or under-damped. Then, the damping factor of the wave equation model can be adjusted so that new downhole data can be generated with appropriate damping.
Abstract:
Rod Float Mitigation (RFM) methods for rod-pumped oil wells having a variable frequency drive which controls the speed of the motor for the pump. Each method monitors rod loads or a similar condition and takes action only when rod load drops below a predefined minimum load. A first method reduces the speed of the motor to a preset level. A second method fixes the torque level on the pump downstroke by adjusting motor speed based on a calculated gearbox torque compared to a programmed fixed limit. Another method includes a program in the variable frequency drive which includes a preferred RFM Torque Curve for the pump to follow on its downstroke. When rod float occurs, the program monitors gearbox torque and adjusts the speed to follow the predetermined RFM Torque Curve thereby mitigating rod float with minimum decrease in production.
Abstract:
An apparatus and method for monitoring a reciprocating member of a reciprocating piston compressor is presented. The apparatus and method provide a means for measuring parameters of the reciprocating member, such as road load or cross-head temperature and the like, and wirelessly transmitting the data to a receiver. A mobile assembly is attached to a reciprocating member of the compressor, the mobile assembly having a sensor assembly, a wireless transmitter and a power generation assembly. The sensor assembly measures a parameter of the reciprocating member and generates a representative sensor signal. The wireless transmitter wirelessly transmits a corresponding data signal to a stationary assembly mounted nearby. The power assembly powers the transmitter and sensor assembly. The measured data is used, in conjunction with other measurements, such as a crankshaft encoder, to calculate the work performed by the compressor, the power used by the compressor and other information. The compressor utilization is then optimized based on the gathered information.
Abstract:
The present invention generally provides apparatus and methods of operating a pumping system. The pump control apparatus includes a first sensor for measuring strain on a structure of the well pumping system and a second sensor for measuring a position of the structure. The apparatus also has a controller configured to control the well unit by receiving output signals from the first and second sensors and generating control signals according to a motor control sequence. This controller may be mounted to the structure of the pumping system to measure the strain experienced by the structure. The control signals may be transmitted to a motor control panel using a cable-less communications system. Preferably, the first sensor, the second sensor, and the controller are integrated into a single unit. In another embodiment, the pump control apparatus may be self-powered.
Abstract:
An apparatus and method for monitoring a reciprocating member of a reciprocating piston compressor is presented. The apparatus and method provide a means for measuring parameters of the reciprocating member, such as road load or cross-head temperature and the like, and wirelessly transmitting the data to a receiver. A mobile assembly is attached to a reciprocating member of the compressor, the mobile assembly having a sensor assembly, a wireless transmitter and a power generation assembly. The sensor assembly measures a parameter of the reciprocating member and generates a representative sensor signal. The wireless transmitter wirelessly transmits a corresponding data signal to a stationary assembly mounted nearby. The power assembly powers the transmitter and sensor assembly. The measured data is used, in conjunction with other measurements, such as a crankshaft encoder, to calculate the work performed by the compressor, the power used by the compressor and other information. The compressor utilization is then optimized based on the gathered information.
Abstract:
A system for monitoring performance of a pumping unit of an oil well includes a first sensor for measuring the inclination angle of a beam forming part of the pumping unit, a second sensor for measuring the load on the beam, and a third sensor for measuring the load on an electrical motor used in conjunction with the pumping unit. The first sensor includes a cantilevered pendulum member which moves in response to changes in the beam inclination angle and strain gauges affixed to the pendulum member for generating an electrical signal indicative of the instantaneous inclination angle. The second sensor includes a deformable sensor plate mounted to the beam and piezoresistive gauges attached to the plate for providing a signal indicative of the load on the beam. The third sensor includes a sensor head attached to a cable for supplying electrical power to the motor. The sensor head includes a sensor coil spaced from the cable so that the magnetic field surrounding the cable induces a current flow in the sensor coil. By measuring the voltage across the ends of the sensor coil, a signal indicative of the load on the motor is generated.
Abstract:
A control circuit for turning off the electrical power to the drive motor, which reciprocates a polished rod of a pump, when the pump has exhausted the supply of liquid in the well. Simultaneously measuring the polished rod load and rod position and turning off the power when the load is greater than or equal to a preset load and the position is equal to a preset position on the downstroke of the well. A first comparator measures the polished rod load relative to a preset load, and a second comparator measures the polished rod position relative to a preset point so that the power is shut off when the load is greater than or equal to the preset load and the position is equal to the preset point on the downstroke. A set of digital latches act to insure that the load is greater than the preset load for two consecutive strokes before the power is shut off. Measuring when the polished rod load is less than a preset load and the polished rod position is equal to a preset point on the upstroke and turning off power to the well and signalling that an abnormal condition exists at the well. Connections are provided for an external plotter so that a plot of load versus position can be plotted to give a visual representation of the well activity.
Abstract:
Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.
Abstract:
An adapter for a load cell in a rod pump system includes an outer shell including a mounting portion configured to attach to the load cell on a polished rod, a power supply configured to provide power to the adapter and the load cell, the power supply including a solar panel on the outer shell, a cable configured to connect to the load cell, the adapter configured to provide power to the load cell via the cable, and the adapter configured to receive a load signal from the load cell via the cable, a signal processor configured to receive and process the load signal and to output load signal data representative of a load experienced by the load cell, and a wireless transmitter to transmit the load signal data.