Three-phase separation downhole

Abstract

Three-phase separation is achieved downhole in a production well by forming an oil / liquid separation zone in the well between two packers which are positioned between producing and disposal zones. Gas is permitted to separate above the top packer. A pump is used to pump an oil / water mixture from above the top packer into the separation zone. Adequate residence time is permitted in the separation zone to achieve the separation. A check valve in the bottom packer is used to provide pressure to raise the oil to the wellhead. A control valve at the wellhead is used to control pressure in the separation zone and the relative sizes of the streams issuing therefrom.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]This application is a division of U.S. application Ser. No. 12 / 449,441, filed Aug. 7, 2009, now ______, which was a section 371 of PCT application number PCT / US2008 / 001698, filed Feb. 8, 2008, which claimed the benefit of U.S. provisional application No. 60 / 900,468, filed Feb. 9, 2007.FIELD OF THE INVENTION[0002]This invention relates to separating three phases downhole, for example, oil, gas and water, and producing separate streams of each.BACKGROUND OF THE INVENTION[0003]The disclosures of Michael et al, U.S. Pat. No. 7,150,315, issued Dec. 19, 2006, and Cognata, US 2006 / 0027362, published Feb. 9, 2006, now U.S. Pat. No. 7,255,167 issued Aug. 14, 2007 are incorporated by reference herein.[0004]Hydrocarbon producing wells often produce mixtures of oil, gas and water. The water must be safely disposed of. Often, it is stored in surface tankage on the wellsite and trucked away to a disposal well. The procedure causes great expense, and c...

AI Technical Summary

Benefits of technology

The patent text describes a method and apparatus for controlling the separation of oil, gas, and water phases in a well. The technical effects include improved oil / water separation, reduced water droplets in produced oil, and the ability to control the pressure downhole for efficient oil production. The apparatus includes a pump assembly and a separation chamber with valves for controlling fluid flow and pressure. Overall, the invention allows for more efficient and effective oil / gas / water separation in downhole production operations.

Problems solved by technology

The procedure causes great expense, and can cause the well to be shut in if the amount of hydrocarbons being produced does not generate sufficient profits to cover the expense of water disposal.

The heavy trucks involved also damage the secondary roads often found in oil and gas producing areas.

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