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US 6,875,351 B2Granted
Methods and apparatus for oil demulsification and separation of oil and suspended solids from produced water
AssigneeHydrotreat, Inc.
InventorJohnny Arnaud
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Abstract
Methods and apparatus for demulsifying oil in water by dilution and impact, and for separation of the oil and suspended solids by dissolved gas floatation, are described. A produced water treating system is also described. The produced water treating system may include a dissolved gas floatation clarifier system, an oil demulsification system, and a separation system. A demulsification subsystem is also described. The apparatus may include a liquid-liquid fluid mixer and a gas generator.
Claims27
A water treating system for treating produced water containing suspended solids and emulsified oil, the water treating system comprising:
- a dissolved gas floatation clarifier system to remove suspended solids and emulsified oil as sludge, the dissolved gas floatation clarifier system adapted to separate the produced water into clarified water and sludge of suspended solids and emulsified oil, and
- an oil demulsification and separation system to demulsify and remove oil remaining in the clarified water from the dissolved gas floatation clarifier system, in which the dissolved gas floatation clarifier system comprises:
- a dissolved gas floatation clarifier having a manifold, a clarified water outlet, and a sludge collection chamber to collect sludge, the dissolved gas clarifier being enclosed;
- a storage tank for collecting clarified water exiting the outlet of the dissolved gas floatation clarifier;
- a pressurized gas supply in fluid communication with the dissolved gas floatation clarifier to supply pressurized gas to the dissolved gas clarifier;
- a recycle pressure aeration system adapted to pressurize the clarified water from the storage tank with a recycling pump;
- a dissolved gas generator adapted to dissolve gas from the dissolved gas clarifier into the pressurized clarified water from the recycle pressure aeration system to form a fluid saturated with dissolved gas to serve as emulsified oil diluent and to supply flotation bubbles to the dissolved gas flotation clarifier;
- a water pump adapted to pressurize the produced water;
- and
- a liquid-liquid fluid mixer adapted to mix the pressurized produced water from the water pump with the fluid saturated with dissolved gas exiting the dissolved gas generator to dilute the emulsified oil and form a mixture of demulsified oil and excess dissolved gas with water, the liquid-liquid fluid mixer providing the mixture to the manifold of the dissolved gas floatation clarifier,
- wherein the dissolved gas floatation clarifier separates the mixture from the liquid-liquid mixer into sludge and clarified water, the sludge being collected in the sludge collection chamber, the clarified water collected in the storage tank.
8 more elements
A water treating system for treating produced water containing suspended solids and emulsified oil, the water treating system comprising:
- a dissolved gas floatation clarifier system to remove suspended solids and emulsified oil as sludge, the dissolved gas floatation clarifier system adapted to separate the produced water into clarified water and sludge of suspended solids and emulsified oil, and
- an oil demulsification and separation system to demulsify and remove oil remaining in the clarified water from the dissolved gas floatation clarifier system, the oil demulsification and separation system having
- a first fluid mixer adapted to selectively mix clarified water from the dissolved gas floatation clarifier system with light petroleum to selectively produce a mixture of water and light petroleum diluent to mix with any trace demulsified oil;
- a low pressure tank adapted to store fluid and having a lower portion separated from an upper space by a layer of floating oil, the upper space adapted to collect gas;
- a dissolved gas generator adapted to mix water from the lower portion of the low pressure tank with gas from the upper space of the low pressure tank to produce saturated water;
- and
- a second fluid mixer adapted to mix the mixture of water and light petroleum diluent from the first fluid mixer with water saturated with dissolved gas exiting from the dissolved gas generator to dilute the emulsified oil and form a mixture of oil and excess dissolved gas with water, the oil-water-excess dissolved gas mixture distributed in the fluid of the low pressure tank via an upper distributor,
- wherein upon entering the low pressure tank from the upper distributor, the gas comes out of solution to separate oil by floatation, the oil floating above the water in the low pressure tank, the gas collected in the upper space of the low pressure tank above the floating oil, and the water exiting the lower portion of the low pressure tank via a bottom outlet port.
5 more elements
Dependencies are inferred from the claim text.