Oil & Natural Gas Projects
Exploration and Production Technologies
Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed
The project was selected under the Research with Independents solicitation,
DE-PS26-02NT15377. The program is intended to assist small independent oil producers
in testing higher-risk technologies that could keep oil flowing from thousands
of U.S. fields.
Under this project, Peden Energy will install a microturbine in the oilfield,
connect this turbine to a natural gas supply line, connect electric lines from
the turbine output to an oil well, and generate electricity to operate two oil/natural
The microturbine that Peden Energy utilized is an advanced model that will burn
a portion of the natural gas from production and reportedly has an efficiency
level of 50%. An effort was made to recover the heat in a combined heat and
power mode that can increase overall efficiency to 75-80%.
The use of a microturbine and a variable frequency drive has several benefits:
1) production can be increased; 2) mechanical stress is decreased, 3) electrical
and capital expenses for motors, switches, etc. can be reduced; and 4) electricity
costs are cut. Potential improvements of 10% increase in production and 20%
in energy savings are expected.
Maintenance costs and life expectations for the microturbine are predicted to
be more favorable then those for internal combustion (IC) engines (generators)
and therefore offer a more favorable life-cycle cost and performance. Currently
available options for power supply in the oilfield are traditional electric
grid power delivered through power lines or IC enginers at the wellsite. Grid-supplied
power is typically one of the highest operating costs associated with a producing
oil/gas well and is subject to disturbances or outages. IC engines are typically
30% or less efficient and require frequent refueling with gasoline/diesel.
In conjunction with the microturbine, this project installed two variable-frequency
drives with computerized pump-off controllers onto two pump jacks. A variable
frequency drive adjusts and varies the pumping speed of the well based upon
downhole torque demand. The greater the torque, the faster the pumping; as torque
demand decreases, the pump speed is decreased.
This variable speed drive-enabled pump control capability enables the operator
- Automatically adjust pumping speed to match the well productivity and automatically
prevent pumping off and shutting down. By maximizing stroke speed during low
torque demand, total strokes per minute are increased and can lead to a 10%
or greater increase in oil production.
- Start motors at minimum frequency (soft start, therefore reducing mechanical
stress) and ramp smoothly to full power. Capital expenses also are reduced,
as smaller-horsepower electric motors can be used because of the soft-start
- Achieve optimum matching of production capability and lowest power cost, by
slowing the beam during peak power demand and increasing the speed during low
torque demand on motors. Through this process, a small independent can reduce
power demand, maintain minimal power usage per stroke, and anticipate energy
savings of up to 20%.
Current Status (October 2005)
The project has been completed, and the final report is in progress.
Project Start: June 30, 2003
Project End: March 31, 2005
Anticipated DOE Contribution: $100,000
Performer Contribution: $125,314 (56% of total)
NETL - Jim Barnes (Jim.Barnes@netl.doe.gov or 918-699-2076)
Peden Energy - Randy Peden (firstname.lastname@example.org or 806-897-2069)