In 2005, SSi Artificial Lift Systems installed a Model 600 Unit with a 125 Horsepower, Intelligent Control Unit in North Dakota. A recent trip to this unit was made in early August 2023 to replace the 125 Hydraulic Power Unit with a 75 Horsepower Unit, this design allowed the clients to relocate the downhole pump to a different depth which provided a new lease of life for this system with increased production. The Pumping Unit and the HPU have common interfaces so it is completely interchangeable. This system operated throughout the whole time without any failures of the hydraulic system or any other part of the installed unit.
The temperatures experienced in these areas range from -47 Deg C in Winter with up to 34 Deg C in the summer. The elastomers are designed to operate within this range of temperature, but the units are equipped with heater systems so that the hydraulic oil within the system constantly remains at the optimum operating temperature. Conversely, if the oil heats above the optimum temperature, a cooler system automatically engages until the oil drops back to the optimum range. The unit will not begin to operate until the oil is fully heated despite the actual outside temperature. Upon initial operation, the unit will short stroke allowing the oil within the cylinder to be replaced and the colder oil is then circulated back to the tank allowing the complete system to operate at the optimum temperature.
The SSi System has independent up and down strokes and it also has features that prevent the downhole rods being put into compression or cause damage to the downhole pumps. It automatically slows down when a loss of load is detected. This unit has been operating for 18 Years and they have only replaced the Rods and Pumps Four Times during this period. With the reduction in the well intervention, the unit tracks back easily and allows the Workover Rig to change the equipment easily and quickly. This means that since 2005, the Operator has saved a significant number of monies, but more up time equates to more oil production.
The system in 2023 showed the following statistics and the hydraulic system has operated without any down time since the installation in 2005:
- Total Number of Cycles as of end of August 23 = 23,283,595
- Total Runtime = 158,400 Hours or 6,600 Days
- Max Peak Polished Rod Load = 38,773 lbs
- Min Peak Polished Rod Load = 19,420 lbs
- Stroke length = 313 inches (The Maximum for this unit is 336 inches)
- The Average Strokes per Minute = 2.45
This success and longevity of service is attributed to several factors throughout the life of the equipment:
- Patented Design of the Cylinder with carefully selected elastomeric materials
- Planned Preventative Maintenance carried out by SSi
- Wells Balanced consistently (unit does not shut down to balance the well no production loss)
- Units not run on highest load or maximum Strokes Per Minute
- Key Features extend the life of the downhole rods and pumps
- Fully Trained Operators in our technology
- Wells Optimized – Dynacards analyzed regularly
In summary, the long, slow stroke provides optimum production, extending the life of the Rods and Downhole Pumps. The system has fully demonstrated the reliability of the hydraulic system reducing the cost for the operator during the complete life cycle.