# Environmental Costs of Managing Geological Brines Produced or Extracted During Energy Development
Christopher B. Harto Argonne National Laboratory Groundwater Protection Council Annual Forum Atlanta, G A 

### September 24 - 28, 2011

### Acknowledgments

 DOE/NETL provided funding to support the work

 Andrea McNemar

- NETL

 John Veil
– Veil Environmental

### Topics Addressed

 Energy systems that produce brines

 Composition of typical geological brines

 Water management options

 E nvironmental costs of water management

### Sources of Geological Brines

 Produced and Flowback Water from Oil and Gas Operations

 Water Extracted from Deep Saline Aquifers used for Carbon Sequestration

 Spent Geofluid from Geopressured Geothermal Systems

Photo by Corrie Clark Photo by John Veil

Diagram by John Veil

### Water Composition

 Examples of the geochemical data

– Formation TDS varies significantly by location

– Formation pH ranges from slightly acidic to slightly basic


###  Management solution must be targeted to unique local brine chemistry

 Note: data for geological formations of interest for carbon sequestration

Source: Harto and Veil 20116 

## Variation in TDS Between Regions

Source: Harto and Veil 2011

## Water Management Options

 Reuse

 Use as is

– Injection for recovering more oil

– Hydraulic fracturing or drilling fluid

– Enhanced geothermal systems makeup water

– Injection for hydrological purposes


###  Use after treatment

– Industrial

– Cooling water

– Dust control

– Agricultural

– Irrigation

– Livestock

– Drinking

Source: USFWS

### Water Management Options

Thermal Treatement Membrane Processes

Photo by John Veil

Photo by John Veil Photo by Chris Harto Treatment 

### Technologies for TDS/Salt Removal

### Water Management Options

 Disposal of Extracted Water

– Injection to non

- hydrocarbon producing formation (UIC class II)

– Evaporation

Photo by John Veil Photo by John Veil

### Balancing Environmental Costs and Benefits

 When selecting a water management you must weight the costs and benefits of the alternatives

 Hybrid life cycle assessment (LCA) approach used to compare

– Energy consumption

– GHG emissions

– Net water savings

Source: EPA 2006

### Hybrid Life Cycle Assessment

 Combines process based LCA approach with economic input

output LCA approach (EIOLCA).
 Process approach

– Ideal for well characterized processes

– Requires lots of specific data

– Suffers from cut

- off error


###  EIOLCA approach

– Suitable for more general processes

– Only requires capital costs

– Suffers from aggregation error


###  Process approach utilized for direct process inputs
 EIOLCA approach used to consider capital equipment impacts

### Example Scenario: Marcellus Shale

 Analysis for a single well in Marcellus Shale

 4 options considered

– Thermal treatment on site

– Thermal treatment at centralized facility

– Thermal treatment at centralized facility utilizing waste heat

– Transport to UIC injection well


###  Key Scenario Parameters

– Transportation distance (0, 30, 150 miles for on site, centralized facility, injection)

– All transportation by truck

– Concentrate disposed of through UIC class II injection in Ohio

### Results

 Higher efficiency of central location outweighs the energy for transportation for energy and GHG
 Thermal treatment more energy intensive than injection unless waste heat used
 Net water s avings

– Treatment system returns 0.66 bbl of clean water for every 1 bbl treated 

###  Other considerations

– Availability

– # of truck trips

– costs 0 50,000 100,000 150,000 200,000 250,000 300,000 350,000 400,000 450,000

On Site Central Central/Waste Heat InjectionLife cycle energy BTU/bbl Life Cycle Energy Consumption Waste Disposal Tranportation Capital Operations

0 5,000 10,000 15,000 20,000 25,000 30,000

On Site Central Central/Waste Heat InjectionLife cycle GHG emissions g CO2e/bbl Life Cycle GHG Emissions
Waste Disposal Tranportation Capital Operations

### Further study in progress

 Management options will be included for further s tudy

– Reuse without treatment for TDS

– Treatment to remove TDS

• At least one reverse osmosis system
• At least two thermal treatment systems

– Disposal

• Deep well injection
• Evaporation


###  Consider alternative transportation parameters

– Truck vs. Pipeline

– Transportation distance


###  Explore impact of water quality (TDS)

### Final Thoughts

 A number of energy development activities can result in the production of large quantities of salty water.

 Managing these brines can be a challenging, but must be done in environmentally responsible manner.

 When selecting the best management practices a number of factors should be considered in addition to cost.

 LCA is one useful tool for comparing the environmental footprint of competing options.