APPENDIX E - Integrated treatment of produced water by chemical and biological unit operations, A subpart of project - Quantifying water availability impacts and protecting water quality while developing Utah oil shale and sands - Final Project Report - Reporting period: June 21st, 2006 to October 21st, 2009

Water generated along with oil, gas, and coal bed methane production is commonly known as produced water, formation water, or oilfield brine [1]. Produced water represents the largest waste stream volume in production operations on most offshore platforms [2]. According to the American Petroleum Institute (API), about 20, 18 and 14 billion barrels (bbl) of produced water were generated by U.S. onshore operations in 1985, 1995 and 2002 respectively, showing a decreasing tendency for produced water generation over time. Although it was not easy to get an accurate estimate of produced water generated offshore, a rough estimate of 175 million bbl per year indicates that production volumes are several orders of magnitude less than the onshore generated produced water [3]. With rapid expansion in the development of fossil energy resources to meet the ever-increasing demand for energy and the maturation of oil and gas fields, the U.S. Geological Survey (USGS) notes that the generation of produced water is undergoing a significant increase. Furthermore, the U.S. Department of Energy as forecasted the current levels of 250 million bbl of produced water per day to increase to 312 million bbl per day by 2015.