Technical Considerations for Hydraulic Fracturing and Groundwater Protection
January 23, 2012
By Wilma Subra
Subra Company
Technical Advisor to LEAN
Baseline Testing of Ground Water
- Perform Testing of water wells before oil and gas activity occurs
- Determine quality of ground water
- Identify chemicals currently in the ground water source prior to horizontal drilling and hydraulic fracturing of shale gas plays
Chemicals in Hydraulic Fracturing Fluids
- Surfactants:
- Laurel Sulfates
- Glycol
- Alcohol
- Hydrocarbons
- Friction Reducers:
- Polyacrylamide Polymers
- Petroleum Distillates
- Glycols
- Biocides:
- Gluteraldehyde
- Quaternary Ammonia
- 2,2-dibromo-3-nitrilo-propionamide (DBNPA)
- Sodium Salts
- Sodium Hydroxide
- Bromide Salts
- Alcohol
- Corrosion Inhibitors:
- Polyacrylamide
- Hydroxyethyl Cellulose
- Alcohols
- Organic Acids
- Glycol
- Amide
- Scale Inhibitors:
- Ethylene Glycol
- Organic Acids
- Alcohols
- Polymers
- Gelling Agent:
- Guar Gum
- Fumaric Acid
- Adipic Acid
- Hydrocarbons
- Polymers
- Foaming Agents:
- Alkylamines
- 2-Butoxy Ethanol
- Diethanolamine
- Ethanol
- Isopropanol
- Polyglycol Ether
- Acids:
- Hydrochloric Acid
- Formic Acid
- Breakers:
- Diammonium Peroxodisulfate
- Borate
- Potassium Salts
- Sodium Salts
- Crosslinkers:
- Boric Acid
- Ethylene Glycol
- Monoethanolamine
- Sodium Tetraborate Decahydrate
- Iron Control:
- Sodium Compound
- Citric Acid
- Carboxylic Acid
- Proppants:
- sand
- ceramic
Thus in order to determine potential impacts to ground water, the fracturing fluid components should be analyzed in groundwater resources.
Chemicals From Rock Formations
- Heavy Metals:
- Aluminum
- Arsenic
- Barium
- Cadmium
- Calcium
- Chromium
- Iron
- lead
- Manganese
- Strontium
- NORM (Naturally Occurring Radioactive Materials):
- Radium-226
- Radium-228
- Radon
- Uranium-238
- Gases:
- Methane
- Ethane
- Propane
- Butane
- Pentane
- Brine/Salt Water:
- Hydrogen Sulfide
- Total Dissolved Solids
- Sodium
- Chloride
Chemicals in Produced Water
- Volatile Organic Chemicals
- Heavy Metals
- NORM
- Ra- 226
- Ra-228
- Uranium-238
- Chloride
- Bromide
- Fluoride
- Iodide
Chemicals in Flow Back Water
- NORM
- Ra-226
- Ra-228
- Uranium-238
- Arsenic
- Barium
- Boron
- Bromide
- Cadmium
- Chloride
- Iron
- Magnesium
- Manganese
- Potassium
- Sodium
- Strontium
- Sulfate
- VOCs
- Benzene
- Toluene
- Ethylbenzene
- Xylene
- Butyl Alcohol
- Butylbenzene
- Carbon disulfide
- Chloroform
- Dioxane
- Isopropylbenzene
- Isopropyltoluene
- MEK
- Naphthalene
- Propylbenzene
- Styrene
- Trimethylbenzene
- Aromatic Hydrocarbons
- Glycols
Sources of Groundwater Contamination
- Surface spills and leaks
- Well cement failure
- Well casing failure
- Rock fractures
- Pipeline leaks and failures
- Seismic Testing
- Abandoned wells
- Produced Water
- Flow Back Water
- Hydrocarbon Products - Oil, Gas, Condensate
- Seismic Drilling and Test Materials
- Drilling Chemicals and Products
- Drilling Cuttings
Baseline Water Well Testing
- Before oil and gas related activity occurs in the area
- Quarterly (seasonal variations) prior to drilling
- Prior to drilling each of the wells on a pad
Follow Up Water Well Testing
- Annually after fracking of final well on the pad and/or in the area
- When a change in water quality is noted
- When a problem is detected or suspected
- When a problem occurs at the well site, along a pipeline, along a haul road or at a compressor station
Location of Water Wells to be Tested
- Distance from well to be drilled:
- Within 1,000 feet of well head
- Within 2,000 feet of well head
- These distances are not adequate to cover subsurface well extent
- Horizontal portion of wells can extend one to two miles from well head surface location
- Water Wells within 0.5 miles of the area to be impacted by the proposed well
Sample Testing
- Who should do the collection and analytical testing of the water well samples?
- State and/or EPA Certified Labs
- Who should pay for the testing:
- Individual home owner
- Company holding the lease if testing is included in the lease agreement or required by government regulations
- Government agency owning the well
- Industrial Facilities using groundwater resources
Information Recorded on Each Well
- Well Location (GPS)
- Well Depth
- Well Pump Depth
- Water depth if possible
Collect water sample prior to softener or treatment system
Provide analytical results to each water well owner
Indicators of Water Contamination from Oil and Gas Drilling and Production
- Volatile Organic Compounds (VOCs)
- Benzene
- Toluene
- Ethyl Benzene
- Xylene
- Organics
- 2-Butoxy Ethanol
- Diethanolamine
- Ethanol
- Ethylene Glycol
- Glycols
- Isopropanol
- Metals
- Arsenic
- Barium
- Boron
- Strontium
- Chemicals
- Ammonia
- Boric Acid
- Bromide
- Chloride
- DBNPA
- Fluoride
- Formic Acid
- Hydrochloric Acid
- Iodide
- Nitrate
- Sodium
- Sulfate
- Total Dissolved Solids
- Coliform Bacteria
- Radium Isotopes
- Ra-226
- Ra-228
- Uranium-238
- Gross Alpha
- Gross Beta
- Gases
- Methane
- Ethane
- Propane
- Butane
- Pentane
Groundwater Baseline Parameters to be Analyzed
- Volatile Organic Chemicals:
- Complete list of VOCs including Benzene, Toluene, Ethylbenzene and Xylene
- Metals:
- Arsenic
- Barium
- Boron
- Cadmium
- Calcium
- Chromium
- Lead
- Magnesium
- Manganese
- Potassium
- Sodium
- Strontium
- Gases:
- Methane
- Ethane
- Propane
- Butane
- Pentane
- Radiation
- Gross Alpha
- Gross Beta
- Ra-226
- Ra-228
- Ur-238
- Chemicals:
- 2-Butoxy Ethanol
- Chloride
- Glycol
- Hydrogen Sulfide
- Iron
- pH
- Nitrates
- Sulfate
- Total Dissolved Solids
- Total Suspended Solids
- Coliform Bacteria
Additional Parameters if Contaminants Detected:
- Acid/Base Neutral Semi-Volatile Organics
- Phenols
- Ketones
- Polynuclear Aromatic Hydrocarbons
Baseline Testing of Groundwater is necessary in order to determine the quality of the groundwater prior to drilling and fracturing activities.
If surface water resources in the area are thought to be at risk, baseline testing of surface water resources for the same analytical parameters is recommended.
