The largest-volume waste stream associated with oil and gas production is produced water. Treatment and disposal of produced water represent significant costs for operators. A relatively new technology, downhole oil/water separators (DOWS), has been developed to reduce the cost of handling produced water. DOWS are devices that separate oil and gas from produced water at the bottom of the well and reinject some of the produced water into another formation or another horizon within the same formation, while the oil and gas are pumped to the surface. Since much of the produced water is not pumped to the surface, treated, and pumped from the surface back into a deep formation, the cost of handling produced water is greatly reduced. When DOWS are used, additional oil may be recovered as well. DOWS may also be referred to as DHOWS or as dual injection and lifting systems (DIALS). This paper summarizes the findings of a report on the technical, economic, and regulatory feasibility of DOWS technology that was funded by the U.S. Department of Energy and prepared by Argonne National Laboratory, CH2M Hill, and the Nebraska Oil and Gas Conservation Commission.1 

You can access this article if you purchase or spend a download.