Water Re-Use: No Silver Bullets

  No single technology fits every situation

  Variables include:

–  Location

–  Water discharge regulations

•  Surface discharge

•  Storage in above ground structure

•  In ground pits

–  Quality of influent water

–  Desired quality of effluent water

–  Disposal costs

–  Re-Use options

–  Transportation

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Water Treatment Technologies

  TSS/Selected TDS Removal

–  Systems remove suspended solids and some dissolved solids depending on process used.

–  Most are very mobile and can be re-located and set up in short amount of time.

–  Does not remove salt from water.

–  Most are capable of processing high volumes

–  Limited waste streams of solids and liquids

–  Examples are Electro-Coagulation, Nano-Filtration, Ultra-Filtration, or Clarifier

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Water Treatment Technologies

  Reverse Osmosis

–  Mobile treatment for salt removal from wastewater

–  More economic than evaporative system

–  Limited by TDS level of 50,000 ppm

–  Quality pre-treatment necessary

–  Recovery of “fresh-water” based on TDS of influent water

–  Three Products Produced

• Fresh-water

• Concentrated brine

• Solids

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Water Treatment Technologies

  Thermal/Evaporative Technologies

–  Typically less mobile for same output as reverse osmosis system

–  More costly than a reverse osmosis system

–  Highest efficiency of freshwater recovery from wastewater

–  Efficiency based on influent TDS

–  Many can use waste heat to lessen energy costs

–  Three products generated

•  Fresh-water

•  Concentrated brine

•  Solids

–  Examples

•  Evaporators

•  Mechanical Vapor Recompression

•  Crystallizers 4

(Poor) Reclaimed Oilfield Waste Water Quality (High)

No Treatment

Course Filtration w/ Dilution

Chemical Treatment & Separation

RO / FO / Evaporation

(Low) Reclaimed Wastewater Treatment cost (High)

( (High) Down-hole Quality Risks (reuse) / Environmental Risks(discharge) (Low))

High Scale, High Bacteria,

High Suspended Solids, High TDS

Ultra-Low Scale, No Bacteria,

No Suspended Solids Low TDS

Water Treatment Optimization

Water Quality Specifications

Analyte   Units   Limits  

Total  Suspended  Solids   mg/L   30  

Total  Dissolved  Solids   mg/L   50,000  

Sulfate   mg/L   1,000  

Stron=um   mg/L   100  

Silica  Gel  Treated  HEM  (TPH  as  HEM)  

mg/L   ND    

Oil  &  Grease  HEM   mg/L   ND  

Magnesium   mg/L   100  

Iron   mg/L   25  

Chloride   mg/L   30,000  

Carbonate  as  CaCO3   mg/L   ND  

Calcium   mg/L   1,000  

Boron   mg/L   10  

Barium   mg/L   100   6

-Example

How much Water can be Re-Used?

  Factors to Consider:

–  Influent water quality

–  Effluent stream desired (Ex: fresh-water, clean brine, etc.)

–  Purpose of re-use

•  Hydraulic fracturing

–  Type of frac (Ex: slick-water, gel fracs etc.)

•  Drilling

–  Volume of water available

•  Flow-back

•  Produced water

–  Chemical costs associated with quality of water

•  Bio-cide

•  Scale inhibitor

•  Friction reducer 7

Planning for Re-Use

  Centralized vs. Mobile

–  How much water do I have in one area?

–  How long will the facility be in one place?

  Transportation - Trucking vs. Piping

–  Distance water will be moved

–  Costs associated with each

–  Quality & size of pipe needed

  Available Space for Equipment

–  Terrain

–  Size of location

  Re-usable Water Recovered

–  Quality of water needed

–  Will this water be blended with other water sources?

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Planning for Re-Use

  Storage –  Frac tanks

–  In-ground ponds

–  Above ground containments

  Disposal Options –  Solids

–  Concentrated brine

–  Sludge

  Cost –  Processing

–  Mobilization/De-Mobilization

–  Site construction

–  Maintenance 9

Planning for Re-Use

  Regulations/Restrictions in Area of Operation

–  Can I surface discharge water?

–  Are there disposal wells in operation?

–  What are pond storage guidelines?

–  Can the water be sold for other uses?

  Land-Owners

–  Acquiring land

–  Additional activity expected

  Commercial vs. Private

–  Is the facility open to the public?

–  Tracking incoming water tickets and reporting

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Why Recycle?

  Less Impact on Surface/Groundwater Resources

–  Fewer water wells and costs associated with operating/maintaining

•  Costs of new wells ranges from $30K-$225K/well

•  Rate of water wells decreases over time

–  Savings of paying landowners/municipalities for accessing water

  Self-Reliance of a Known Resource

–  Water recovery from oil/gas wells

–  Less disposal = fewer SWD’s

  Less Time to Fill Ponds for Future Operations

–  More wells can be drilled/completed in shorter time due to water availability

  Influence Future Regulations/Permitting Procedures

  Positive Perception by the Public

  It’s The Right Thing To Do

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Water Recycling Conclusions

  Most of the technologies are already proven

  Transportation and storage logistics are critical

  Varying levels of water treatment impact cost

  Texas operations have low cost water sourcing options and low cost produced water disposal options

  Recycling is more of an economic challenge than a technical challenge

  New technologies are being developed that should help to lower cost of recycling while providing a quality water to store, transport and use in future operations.

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Water Treatment

QUESTIONS?

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