US Department of Energy

Project Title:

De-oiling and desalination of water produced during oil and gas recovery operations including produced water from oil shale

Investigators:

C. Steven Sikes, L. M. Ringsdorf, T. D. Sikes, and M. N. Wickham

Project Summary:

Oil and gas recovery operations produce large amounts of water both from the formations and from water used as part of the recovery process.  This produced water is typically oily and contains residuals of solids like sand and clays.  It often is saline.  It must be cleaned and made fresh before re-use or return to the environment.

            We use about 20 million barrels of oil per day in the USA at present.  We produce about 8 million barrels of this and import the rest.  Although our reserves of conventional oil have dwindled to 21 billion barrels, we do have recoverable natural gas of about 1,200 trillion ft³, the equivalent of about 200 billion barrels of oil.  In addition, the oil shale formations in Colorado, Wyoming, and Utah contain an estimated 2 trillion barrels, a startling number, more than 10-fold that of Saudi Arabia.  Although the barriers are formidable, both economic and national security concerns are driving renewed attempts to access this resource.

            Serious issues such as water usage and environmental protection remain associated with oil and gas recovery of all types.  As explained herein, advances in water treatment and recycling are proposed that may resolve the environmental issues.  Included are approaches to restoring produced water to a new standard of cleanliness. 

            Our novel chemistries, methods, and commercial processes for clarifying water produced during recovery operations have been developed in the oil sands region of Alberta, Canada.  These patented and patent-pending chemistries and treatments are currently undergoing widespread adoption there.  Our treatment chemicals are both biodegradable and environmentally benign.  Our methods work in a few minutes rather than hours-to-years, as has been the practice.  The water is completely clarified and recycled to the process stream with little or no release to the environment.  Water use is minimized.  The sources are on-site wells rather than surface water.  The most difficult-to-treat samples have often been highly saline.  Hence, our work also includes novel approaches to desalination of produced waters.

Our treatments apply not only to oil and gas operations in general, but also to separations of a wide variety of solids from water.  We can treat agricultural waters like irrigation streams and impoundments, waste streams from animal husbandry operations, paper processing streams, and both municipal water and sewage.  The proposed studies would support many public benefits including production of our own oil rather than obtaining it from foreign sources.