Enhanced Oil Recovery

Xerox has patents for license or sale, that describe the use of pre-defined ultrasonic waveforms to increase the recovery of the oil from oil reservoirs. Currently available recovery methods recover only about half of the oil in a natural oil reservoir. Use of this technology can potentially increase oil production.

Technology Description

Xerox's ultrasonic oil recovery systems and methods, as embodied in the patents, involve injecting an aqueous composition, such as steam or water, into an oil reservoir. The oil reservoir is then subjected to ultrasonic waveforms, applied at specific frequencies, phases and amplitudes to release additional oil from the porous rock structure. Factors such as the permeability of the oil field rock formation, rock porosity, oil fluid density and viscosity determine the waveform characteristics.

The waveforms then excite a second sound mode, where the porous rock oscillates out of phase with the oil fluid trapped in the pores of the permeable rock structure. This causes the porous rock structure and the oil fluid trapped in the rock structure to move in opposite directions. This process, known as "second sound" or the Biot slow wave, is used to move oil in the porous rock structure towards the already existing oil flow pathways, known as "percolation paths". Thus, oil that might otherwise be unrecoverable is recovered.

The patents further encompass systems and methods by which the waveforms can be directed to specific locations within the permeable rock structure. Multiple ultrasonic waveform generators and phase controls are used to create the second sound effects. The second sound effect can be directed at specific sites and controlled depths within the reservoir, thereby creating an optimization of the oil flow patterns of the reservoir to enable maximum oil recovery.

The process can be used not only for oil fields but for almost anything that has a percolation path where solids are to be separated from liquid particles.


  • Increased recovery of oil-that might otherwise be unrecoverable- with conventional methods
  • Extends the life of "spent" oil fields
  • Environmentally safer than other secondary and tertiary recovery methods, through reduced use of chemicals and water
  • Potential production cost savings


  • Oil extraction
  • Solid liquid separations of aggregates, porous structures and materials
  • Waste separation


  • Oil Industry
  • Waste recovery / separation
  • Biomass energy industry
  • Oil Sands industry

Intellectual Property Summary

The patents specific to the Enhanced Oil Recovery technology are listed below. They have been extensively cited by some of the prominent companies engaged in the field of oil field exploration, production and service such as Shell International Exploration and Production B.V., ExxonMobil Upstream Research Company, Coriba Technologies, L.L.C., Baker Hughes Incorporated, and Halliburton Energy Services, Inc.

Other Ultrasonic Intellectual Property

U.S. 7229562 Integrated dual cross filtration and ultrasonic transducer assembly Filtration
U.S. 6376145 Ultrasonic drying of saturated porous solids via second sound Materials Processing

For Licensing Information

To learn more about licensing Xerox Enhanced Oil Recovery technology.