Abstract:
A simplified system and method for remotely monitoring and optionally further controlling pumpjack operating parameters of a pumpjack located at a distant site but within wireless cell phone station reception. Sensors situated on a pumpjack monitor and create analog output of operational conditions of the pumpjack. Digitizing means digitize the analog output of the sensors to digital data, and modem means transmit the digital data via a wireless cellular network to a network server. A user's computer communicates with the network server via the internet, and accesses the digital data to obtain information regarding the operational conditions of the pumpjack.
Abstract:
The present invention provides highly accurate methods for directly calculating pump fillage which avoid the need and expense of a pump dynamometer card and subsequent calculations.
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:
A method is provided to monitor operation of a sucker rod pump, the sucker rod pump having a strain gauge mounted on a walking beam for determination of load. This method compensates for gradual changes in load due to temperature drift when gradual changes in surface card area are occurring and the surface card area or the measured average loads are within a range of a predetermined base surface card area or base average load. When the surface card area or the measured average load is not within this predetermined range, a correction is made to adjust a smoothed minimum load to an adjusted buoyant weight of the sucker rod string. This adjusted buoyant weight is the value that the smoothed minimum load would be expected to be. This algorithm therefore compensates differently for changes in load when the surface card area (or alternatively, the average load) are not within a predetermined value because these changes are generally not due to temperature changes, but due to changes in the operation for which the sucker rod pump monitoring and control system should respond. An alternative correction to the measured load is also provided for time periods when the sucker rod pump is idle.
Abstract:
In a pumping well, oil is normally lifted to the surface by a rod which extends from the surface to a downhole pump. A transducer is attached to the rod at the surface to sense the deformation, i.e., the change in diameter or circumference of the rod to determine change in rod loading. The transducer includes strain gauges which produce output signals proportional to the change in the diameter or circumference of the rod which occurs due to changes in load on the rod. The transducer may also include an accelerometer. The change in load on the polished rod over a pump cycle is used in conjunction with data produced by the accelerometer to calculate a downhole card. The downhole card showing change in pump load is adjusted to reflect absolute rod load by determining an appropriate offset. Various ways to determine the offset are available. Since the pump plunger load is zero on the downstroke when the traveling valve is open, the value necessary to correct the calculated minimum pump value to a zero load condition may be used as the offset. The offset can also be estimated by either a calculation of the rod weight, a predetermined rod weight measurement or an estimated load value by the operator.
Abstract:
A method for controlling a rod pumped well to limit the amount of time the pumping system is subject to fluid pound. The method monitors various pumping system parameters and shuts the pumping system down just before pump-off occurs.
Abstract:
Methods and apparatus to determine operating parameters of a pumping unit for use with wells are disclosed. An example apparatus includes a housing and a processor positioned in the housing. The processor is to determine a rate at which to operate a motor of a pumping unit to enable a load imparted on a polished rod of the pumping unit to be within a threshold of a reference load or to enable a speed of the polished rod to be within a threshold of a reference speed.
Abstract:
Diagnosing a pump apparatus having a downhole pump disposed in a deviated wellbore characterizes axial and transverse displacement of a rod string with two coupled non-linear differential equations of fourth order, which include axial and transverse equations of motion. To solve the equations, derivatives are replaced with finite difference analogs. Initial axial displacement of the rod string is calculated by assuming there is no transverse displacement and solving the axial equation. Initial axial force is calculated using the initial axial displacement and assuming there is no transverse displacement. Initial transverse displacement is calculated using the initial axial force and the initial axial displacement.
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:
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.