Abstract:
A controller for operating a rod pumping unit at a pump speed. The controller includes a processor configured to operate a pump piston of the rod pumping unit at a first speed. The processor is further configured to determine a pump fillage level for a pump stroke based on a position signal and a load signal. The processor is further configured to reduce the pump speed to a second speed based on the pump fillage level for the pump stroke.
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 an upstroke damping factor and a downstroke 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 card is over or under-damped. Then, at least one of the upstroke or downstroke damping factors of the wave equation model is adjusted so that new downhole data can be generated with appropriate damping.
Abstract:
It is an object of the invention to provide a pump jack pump-off control method and a pump jack control apparatus in which, even when the speed of a pump jack is reduced due to generation of a pump-off condition, the pump jack is not caused to stop due to the motor overload abnormality or the coagulated crude oil and, even when the pump-off condition is generated, the reduction of the production capacity of the pump jack can be prevented as much as possible. On detecting the pump-off condition, while the pump jack is in operation with the speed thereof being reduced, or while the pump jack is in operation at the lowest speed, according to the overload warning signal of an ac electric motor, the pump jack is switched over to its intermittent operation. Also, the pump jack can be operated in such a manner that the stroke speed of the pump jack in the up stroke operation can be switched from a sinusoidal wave form over to a rectangular wave form, or, in the operation of the pump jack by an inverter, the pump jack can be operated such that it can carry out its up stroke operation with a limit imposed on torque.
Abstract:
A method and system for pumping unit with an elastic rod system is applied to maximize fluid production. The maximum stroke of the pump and the shortest cycle time are calculated based on all static and dynamic properties of downhole and surface components without a limitation to angular speed of the prime mover. Limitations of structural and fatigue strength are incorporated into the optimization calculation to ensure safe operation while maximizing pumped volume and minimizing energy consumption. Calculated optimal prime mover speed is applied to the sucker rod pump by means of beam pumping, long stroke or hydraulic pumping unit by controlling velocity, acceleration and torque of the electric prime mover or by controlling pressure and flow rate in hydraulically actuated sucker rod pumping system.
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 pump drive assembly is disclosed. The assembly includes a driver, a pump drive member driven by the driver, and a decoupler that decouples the drive member from the driver when a force acting upon the drive member exceeds a threshold force. The pump drive member can be a piston rod, and the decoupler can be a magnet attached to the piston rod and coupled to a magnetically attracted plate driven by the driver. When a force resisting movement of the piston rod exceeds the magnetic force coupling the magnet to the plate, the magnet decouples from the plate, and the pumping operation ceases.
Abstract:
In a liquid well pumping system which is provided with a downtime between pumpoff cycles, the method of determining the maximum downtime includes running a plurality of tests to determine the relationship between runtime and downtime and determining when the relationship becomes non-linear for at least two consecutive tests. The downtime is selected adjacent the last linear relationship between runtime and downtime for providing a downtime which allows adequate fluid buildup in the well, but not so long a period as to loose well production.
Abstract:
A drive and control mechanism for an electrically operated reciprocating apparatus, intended especially for a long-stroke well-pumping apparatus. The mechanism automatically controls the direction of travel of the apparatus and effects reversals at the ends of each stroke. On start-up the apparatus always travels in a direction toward its farther limit of travel. Control is effected without series of sequentially operating relays which can shut down the apparatus unnecessarily in the event any one relay drops out accidentally, as can result from a voltage drop. The circuit includes protective means for shutting down the apparatus immediately in the event certain malfunctions occur, for example, if the parts travel beyond proper limits, or if the apparatus commences to operate at excessive speed, or if a motor overheats.
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.