VFD Automatic Pump-Off with two-byte Modbus addressing for improved efficiency, energy savings, and expanded remote access for natural gas extraction.
Fan on the side of the enclosure maintains internal temperature as to not overheat the components
Just like people, natural gas wells have their own unique characteristics. Even within the same gas field, some wells are super-producers, while others consistently produce a low
volume of gas. and similar to people, wells change on a daily basis depending on environmental factors. In a way, the well is a natural, living thing, and utilizing a one-size-fits-all method to natural gas production will not yield the best results.
A customized approach was the premise for the automated pumpjack solution we created. we began developing an automated solution for a de-watering application that would help our customers gain efficiency in extraction, service and maintenance, while also giving them the ability to watch and control the sites remotely.
We were looking for a smarter approach than the timer box and a contactor that is common in the industry. Instead of having the pump “on” or “off” for a predetermined time, that an operator manually set, which can allow dry cycling and fluid pounding, causing possible damages to the equipment. We developed a system that strikes the fine balance between pumping water out so it’s at as low a level as possible , resulting in ideal gas flow, without actually pumping the well dry and causing premature wear and damage to the pump components.
Algorithms and smart PLC enable condition-based pumping
After years of development and testing we are able to offer and intelligent system that constantly monitors the pump conditions and determines water flow. Once flow has ceased, the program performs calculations to adjust the pump’s idle time so that the minimal amount of water collects before pumping resumes. All this is done with equipment mounted outside of the Class 1/Div 1 hazardous area. There is no need for underground conduit to feed signals from sensitive, expensive and difficult to maintain sensors. The only wires needed are the motor leads.
Once these units were placed on-line our customers discovered that the timer based pump cycle was very inefficient, and the time required for pumping the water would vary based on current conditions. Some wells show more than a 75 percent decrease in energy consumption by only running when water was present. We also engineered the solution to allow the pump jacks to run utilizing less expensive three-phase motors in single phase power locations. Which garnered added energy savings and reduced maintenance costs by eliminating the need for capacitive start single phase motors.
How much water a well produces can vary even on a daily basis depending on the weather, time of the year, and other factors. Our controllers allows each cycle to adapt based on the current conditions. As the PLC sees conditions changing it automatically corrects itself. Our success in this application is due largely in part because we recognized that each well had its own characteristics, and that those characteristics change daily. Essentially, each well has its own customized solution.
Even in extreme cases, the automated pumpjack solution knows what to do. For example, if there is a power outage, the system will “reset” so the pump controller knows that an increased run time is required to pump the extra water out of the column before it can resume optimal production of gas. With the time-based system, the pumpjack would run for the preset time removing only part of the water, while not actually getting the water level low enough to allow for efficient gas flow.
Remote access simplifies field maintenance, connectivity enabled by two-byte addressing
One of the other requirements for a solution was remote monitoring and access to each well site via SCADA network. With one well tender responsible for dozens of wells, especially in remote areas, it was difficult to effectively manage them. Before our automated solution, the well tender’s only option was to get into a truck and drive to the site.
Our solution uses the Modbus open communication protocol which transmits information serially between devices. To move beyond the Modbus standard 247 slave limitation we worked with our hardware vendor to develop proprietary firmware that accommodates two-byte Modbus addressing, which extends the number of slaves in the network to 65,535.
Remote access has many benefits for the customer, including the ability to troubleshoot remotely by detecting and reporting faults. Such as: broken belts, broken bridal, motor faults, power failure, and water tank level. Now the customer can save time and money by checking the status of the sites remotely.
Human Machine Interface
We also have a range of HMI to suit your requirements. All our HMI are powered through the Ethernet cable. The 500 series touch screen gives full access to troubleshooting and configuration, and is intended for technicians. Our 400 series allows well-tenders and operators limited access to the functions required on a day-to-day basis, like timer change, speed adjustments, tank level adjustments and reporting, and current or past faults or errors. The 200 series is designed to allow water tanker drivers the ability to adjust the tank level for the amount of water removed after emptying the tank.
“How can we make it better?”
We are always asking ourselves “how can we make it better?” We continually communicate with our customers to find ways to improve our product and test new features that will be added to help our customers. Do you have a special sensor ( i.e. gas leak detector ) you would like to monitor? Just let us know. We are always open to custom changes to make sure our product meets your specific needs.
One such improvement was in the installation of the panels. We all know how difficult hanging a panel in the field can be, where tools and resources can be limited. So we designed a new “patent pending” pole mount. The installation requires only one lag bolt at the desired height. The panel can then be hung. The mount automatically locks the panel vertically and it can accommodate poles from 6-10 in. or 15.24 – 25.4 cm. No more adjusting band clamps or cutting Unistrut to the desired lengths. It is also available with integrated disconnect mount. Up to 4 additional lag bolts can be added to improve strength.
Another improvement was in tank level monitoring. Are you regularly sending someone to measure tank water level and do not want the cost of adding a level monitoring system? We developed an algorithm to estimate water volume and level. This is reported on the HMI or back through a SCADA system so that water tankers can be more efficiently dispatched. If you are unable to get to the site because of unforeseen conditions, by enabling the “tank-full” feature you can help avoid the risk of overflowing the tank. Simply set how many inches from full you wish to halt pumping. When the controller determines the level has been reached, pumping is halted until the tank level is lowered and the alarm reset. The reset can be done either locally or remotely.
We are confident that our pumpjack solution will help to achieve significant energy savings, a more efficient extraction process, and remote access that allows for proficient service and maintenance.
- External weatherproof bulkhead for HMI connection
- External LED status light to aid in quick trouble evaluation
- Integrated surge suppression and lightning protection
- External Keyed OFF/ON/Manual switch
- Keyed locking door ( custom keying available )
- Thermostatically controlled cooling fan
- Breaker protection
- 8A 120VAC 2-gang GFCI outlet
- All components are UL listed/approved.
- NEMA 4 Enclosure
We now offer standard controllers from 5 – 20HP in both 240VAC and 480VAC 3-phase input, and 3 – 13HP in 240VAC and 480VAC single-phase input. These units are available for delivery in 5-7 days. Custom units up to 100HP are also available, lead time based on part delivery.
||200 – 240VAC
||380 – 500VAC
||Up to 5HP
||Up to 3HP
||Up to 5HP
||Up to 3HP
||7.5 – 10HP
||5 – 7HP
||7.5 – 10HP
||5 – 7HP
||15 – 20HP
||7.5 – 13HP
||15 – 20HP
||7.5 – 13HP
Part # Configuration
AA – Motor Horsepower rating on 3-phase supply power ( see above chart for ranges )
- 05 = 5HP
- 10 = 10HP
- 20 = 20HP
BBB – Supply Voltage
- 241 = 200 – 240VAC single-phase
- 243 = 200 – 240VAC 3-phase
- 481 = 300 – 500VAC single-phase
- 483 = 300 – 500VAC 3-phase
CC – Power Disconnect
- 00 = No disconnect
- 01 = Integrated disconnect ( with close nipple and top power entry )
- 02 = Independent mountable disconnect ( add -xx for seal-tight length -T for top or B for bottom entry )
DD – 120VAC transformer/Outlet ( -01 required on 480VAC units )
- 00 = No 120VAC transformer ( neutral supply wire required one 240VAC for 120VAC Outlet )
- 01 = 1Kw 240/480VAC to 120VAC transformer
EE – Modbus Addressing
- 00 = Single byte standard Modbus addressing ( up to 247 addresses )
- 01 = Two-byte extended Modbus addressing ( up to 65,534 addresses )
FF… – Options
- 00 – No options
- 01 – Radio antenna bulkhead
- 02 – 24VDC controller battery backup
- 03 – 12VDC battery charger ( for external devices, i.e. flow meter )
- xx – Other options
- 240VAC single-phase controller
- Independent mountable disconnect with 24 in. sealtite conduit for top power entry
- No 120VAC transformer ( neutral required for 120VAC )
- Two-byte extended Modbus addressing
- 24VDC controller battery backup
- 12VDC battery charger