Downhole oil–water separation technology Information

From Wikipedia–water_separation_technology

Downhole oil–water separation (DOWS) technology is an emerging technology that separates oil and gas from produced water at the bottom of the well, and re-injects most of the produced water into another formation which is usually deeper than the producing formation, while the oil and gas rich stream is pumped to the surface. DOWS effectively removes solids from the disposal fluid and thus avoids injectivity impairment caused by solids plugging the casing well. Simultaneous injection using DOWS minimizes the opportunity for the contamination of underground sources of drinking water (USDWs) through leaks in tubing and casing during the injection process. [1] [2] [3]


A DOWS system is installed at the bottom of an oil well, where it separates oil and water in the wellbore. The oil-rich stream is brought to the surface while the water-rich stream is pumped into an injection formation without ever coming to the surface. A DOWS system includes many components but the two primary components are an oil/water separation system and a pumping/injection system used to lift oil to the surface and inject the water into a deeper formation. Two basic types of DOWS systems have been developed, one type uses hydro-cyclones to mechanically separate oil and water, and the other relies on gravity separation that takes place in the wellbore. Three basic types of pumping/injection systems are used with the DOWS technology. These include electrical submersible pumps, progressive cavity pumps, and sucker rod pumps. [4] Hydro-cyclone separators are usually used with the electrical submersible pumps because of higher drawdown created with an effective injection of water into the lower zone. [5]


  1. ^ Veil, J. A.; Langhus, B. G.; Belieu, S. (1999-01-31). "Feasibility evaluation of downhole oil/water separator (DOWS) technology". doi: 10.2172/917614. {{ cite journal}}: Cite journal requires |journal= ( help)
  2. ^ Ogunsina, Oluseye Olugbenga; Wiggins, Michael Lloyd (2005-04-16). "A Review of Downhole Separation Technology". All Days. Oklahoma City, Oklahoma: SPE: SPE–94276–MS. doi: 10.2118/94276-MS.
  3. ^ Blanco, A.E.; Davies, D.R. (2001-03-24). "Technical & Economic Application Guidelines for Downhole Oil-Water Separation Technology". All Days. Oklahoma City, Oklahoma: SPE: SPE–67182–MS. doi: 10.2118/67182-MS.
  4. ^ Jiang, Minzheng; Cheng, Tiancai; Dong, Kangxing; Liu, Jintang; Zhang, Huaiyu (2020-08-13). "An Efficient Downhole Oil/Water-Separation System with Sucker-Rod Pump". SPE Production & Operations. 35 (3): 522–536. doi: 10.2118/201234-PA. ISSN  1930-1855.
  5. ^ Patel, Mohit; Patel, Jigarkumar; Pawar, Yogendrasingh; Patel, Nehal; Shah, Manan (2020-02-24). "Membrane-based downhole oil-water separation (DOWS) technology: an alternative to hydrocyclone-based DOWS". Journal of Petroleum Exploration and Production Technology. 10 (5): 2079–2088. doi: 10.1007/s13202-020-00848-x. ISSN  2190-0558. S2CID  211254157.