Technology

Fountain Quail utilizes Aqua-Pure’s breakthrough evaporator technology which is covered by a process patent in Canada, the US, and most oil producing countries worldwide. The Aqua-Pure evaporator is more compact and efficient than competitive systems. These advantages have led to the development of the skid-mounted NOMAD system for oilfield customers that require mobile treatment solutions.

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NOMAD 2000 System

The NOMAD system has the ability to process highly variable oilfield wastewater and return to the producer approximately 85% of the feed volume as distilled freshwater that can be re-used. The NOMAD evaporator system is truly revolutionary. It is a system capable of addressing one of the greatest challenges of economically treating contaminated water, that is the challenge posed by the variable nature and concentration of oilfield wastewater contaminants. Existing methods of treating wastewater; membranes, ion exchange, etc., are most effective when treating water with consistent levels of specific contaminants. Variations in the type and concentrations of contaminants will cause these systems to fail, requiring frequent cleaning or recalibration. Wastewater generated from oil and gas operations is highly variable and therefore very difficult to treat. Having the capability to recycle this wastewater that would otherwise be wasted gives Aqua-Pure access to virtually untapped wastewater markets that have very few, if any, serious direct competitors except disposal.

Evaporation Theory

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Evaporation is a method of producing pure distilled water from Feedwater containing dissolved solids. The Feed water is boiled to produce steam. When the water boils into steam it leaves behind all dissolved solid contaminants. The steam is condensed into pure distilled water.

In order to control the level of dissolved solids in the concentrated boiling fluid, a constant stream is drawn off. This is called concentrate. All of the dissolved solid contaminants that enter the system in the Feed water leave the system in the concentrate.

For Example, a Feedwater stream consisting of dissolved solids (Sodium Chloride (NaCl) Salt) will produce a distilled water stream and a stream of concentrated Sodium Chloride.

Mechanical Vapour Recompression Evaporation

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Mechanical Vapour Recompression (MVR) Evaporation is a highly efficient process for evaporating distilled water from a feedwater containing dissolved solids. The NOMAD units are MVR Evaporators. In MVR systems, a compressor is used to add the energy required to boil feedwater into steam.

The Feedwater enters the NOMAD, breaks into two streams and flows through the Pre-Heat Exhangers. One Feedwater stream cross exchanges with the Distilled Water leaving the system and the other with the Concentrate leaving the system. Both the Distilled Water and Concentrate streams are very hot (near boiling) and transfer heat to the incoming Feedwater. The two hot Feedwater streams don’t re-combine.

The hot Feedwater passes through a De-Aerator. In the De-Aerator, dissolved gases (such as Carbon Dioxide) in the Feedwater are released and vented. The hot de-aerated Feedwater then enters the Recirculation Loop.

The Recirculation Loop consists of boiling Concentrate flowing from the Seperator to the Circulation Pump to the Evaporator Exchange and back to the Separator. The Circulation Pumps, transfer the hot Concentrate from the Separator up through the Evaporator Exchange. In the Evaporator Exchanger, a portion of the hot Concentrate is boiled into steam. A mixture of Steam and boiling Concentrate exits the top of the Evaporator Exchanger and flows into the Separator.

Inside the Separator the Steam is seperated from the boiling Concentrate. The Steam is drawn from the Separator with the Compressor. The Compressor boosts the pressure of the Steam and this causes the temperature of the Steam to go up. The high temperature, high pressure Steam is driven down through the Evaporator Exchanger. As the high temperature, high pressure Steam condenses into Distilled Water, it passes heat to the boiling Concentrate making it boil into Steam.

Hot Distilled Water flows from the bottom to the Evaporator Exchanger into the Distillate Receiver. The hot Distilled Water is pumped from the Distillate Receiver through the Feed/ Distillate Pre-Heat Exchanger where it cools down, passing heat to the incoming Feedwater. The cool Distillate Water then exits the system and flows to the Distillate Pit.

To prevent the Salt concentration from getting too high in the Recirculation Loop, a constant stream of boiling Concentrate is drawn from the Separator with the Concentrate Pump. The boiling Concentrate is pumped through the Feed/Concentrate Pre-Heat Exchanger where it cools down, passing heat to the incoming Feedwater. The cool Concentrate then exits the system and flows into the Concentrate storage tanks.

Boiling water on the stove requires 1000 BTU of energy to product 1 pound of Steam. MVR Evaporation uses a theoretical 50 BTU of energy to produce 1 pound of steam (5% of the energy of conventional evaporation).

Oilfield Wastewater Recycling

Oilfield wastewater recycling is complex and involves many significant challenges:

  • Sources of oilfield wastewater often do not exist for long enough to justify a fixed facility.
  • The cost of transporting wastewater from the source to a fixed facility can make recycling uneconomical
  • High chloride levels require specialized metallurgy to prevent corrosion.
  • Species such as carbonates, sulfates, and silica (CO3, SO4, SiO2) can cause severe scaling.
  • Common oilfield chemical additives can foul filters, heat exchangers, membranes and other equipment.
  • Oil and high levels of suspended solids can foul and plug equipment.
  • Processing hard-to-treat wastewater can be very expensive.

Fountain Quail offers solutions that involve:

  • Installation of small footprint, easy to transport modular systems.  This allows the wastewater to be processed at or near the source reducing the transportation costs.
  • Utilizing many small decentralized facilities minimizes the distance to wastewater sources.
  • Cutting edge technology and practices that are energy efficient, resistant to fouling, robust, and easy to service and maintain.