EEOR – Electrically Enhanced Oil Recovery SM process involves passing direct current (DC) electricity between cathodes (negative electrodes) in the producing well and anodes (positive electrodes) either at the surface or at depth. Important facts include:
- EEOR has demonstrated, in an 18-month field test, the ability to increase heavy oil production ten-fold from baseline levels in a field where other secondary oil recovery techniques were not successful.
- Current steam-based heavy oil recovery methods are effective to about 2,500 feet. EEOR has no depth limitation. According to a NIPER study, more than half of the 68 billion barrels of remaining heavy oil reserves in the U.S. are below 2,500 feet.
- Energy costs for EEOR are less than $4/barrel, and capital costs are a fraction of steam-based methods.
The 3 Mechanisms of EEOR in Heavy Oil Recovery:
- Electro-Chemical Upgrading, or “Cold Cracking” — Oxidation and reduction reactions break down heavy oil molecules into lighter oil molecules, upgrading the oil in the reservoir.
- Electro-Kinetics or Electro-Osmosis — Oil in the reservoir migrates toward the negative cathode, creating a drive mechanism, or flow, towards the well.
- Resistance, or Joule Heating — Oil around the well bore is heated, becoming less viscous and easier to extract.
Advantages Over Steam-Based Technologies
EEOR has several important advantages over competing steam-based heavy oil recovery technologies
- No depth limitations — Steam-based methods are effective up to approximately 2,500 feet while over 50% of US heavy oil reserves are below 2,500 feet.
- Energy costs of less than $4 per barrel produced — Plus lower capital costs than steaming.
- No water supply needed — And does not use a working fluid.
- Produces no greenhouse gases.
- Heat is generated directly in the reservoir — Rather than at the surface.
- Depends upon resistivity, not permeability — And increases apparent permeability in the reservoir.
- No “thief zones.”
- Ability to add capital/infrastructure incrementally allowing for faster cash flow break-even.
- Electro-kinetics influence produced fluid and flow.
Wittle JK and Hill DG, Use of Direct Current Electrical Stimulation for Heavy Oil Production, Society of Petroleum Engineers Applied Technology Workshop – Technologies for Thermal Heavy Oil and Bitumen Recovery and Production, Calgary, Alberta, Canada, March 14–15, 2006.
Wittle JK and Hill DG, Direct Current Electrical Stimulation – A New Approach to Enhancing Heavy Oil Production, First World Heavy Oil Conference, Beijing, China, November 12–15, 2006.
Wittle JK, Hill DG, and Chilingar GV, EEOR – Electrically Enhanced Oil Recovery SM Using Direct Current, Oil Sands Heavy Oil Technologies Conference, July 18-20, 2007.
Wittle JK, Hill DG, and Chilingar GV, SPE-114012, Direct Current Electrical Enhanced Oil Recovery in Heavy-Oil Reservoirs To Improve Recovery, Reduce Water Cut, and Reduce H2S Production While Increasing API Gravity, presented at the 2008 SPE Western Regional and Pacific Section AAPG Joint Meeting, Bakersfield, California, USA, March 31–April 2, 2008.
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