ARE THE LAND AND WATER RESOURCES SAFE FROM HYDRAULIC
FRACTURING ACTIVITIES?
The simple answer is of course, no. There is no human activity that is completely
safe for the land and water resources:
from domestic wastewater generation, handling and disposal, to drilling
for oil and gas, to oil transportation through tankers or pipelines, to chemical
manufacturing, to mining and mining waste, and so on, there are risks and
consequences associated with every activity, including broken pipes, improperly
designed or constructed wells or equipment, human errors, noise pollution, dust,
carcinogenic crystalline frac sand, radioactive wastewater and solid waste, heavy truck traffic, and so on. The 2010
BP Deepwater Horizon oil spill in the Gulf of Mexico comes to our mind as a
prime example of an activity that can create havoc to the land and water
resources through human error and/or criminal conduct. We believe that the key to safeguarding our
resources is to understand what we are doing, the individual process components
involved and to take steps to minimize the risk.
Perhaps many of you have seen the images of the toppled fracking
tanks (Figure 1) and other infrastructure during the Colorado floods in Weld
County or the dumping of fracking fluids in unlined pits in California (Figure
2) and began to question the environmental risk (and as result the potential
liability to the insurer or the insured) created by such activities. This blog attempts to answer some of these
concerns.
Figure
1. Overturned holding tanks in Colorado
following flooding of the fracking fields.
Figure
2. Illegal discharge of fracking fluids
into an unlined pit in California. The
drilling company was fined over $60,000.
As more attention is paid by the public to incidents of
contamination of the land and water resources by hydraulic fracturing, it is
clearly becoming obvious that there is significant dispute regarding the
effects of such activities on the human health and environment. These disputes arise because there is not
much information available, in the form of comprehensive long-term studies, on
the effect of the hydraulic fracturing activities on the groundwater and
surface water resources. The key problem
is that alleged
incidents of oil or gas migration require investigations at the site-specific
level and evaluation and synthesis of multiple data types to determine the
source of the stray gas; this is an expensive proposition considering the length
of the monitoring wells and the required sampling. Thus so far the parties are just sniping at
each other and we are merely waiting for more environmental incidents to happen
for further regulation or other scrutiny to take place.
WHAT
IS HYDRAULIC FRACTURING?
Hydraulic
Fracturing
(also known as “hydrofracking, or “fracking”) has received considerable public
attention due to recent drilling activity in the Marcellus Shale in the
Appalachian region, the Barnett Shale in Texas, and the Bakken Shale in North
Dakota and Montana. Hydraulic
fracturing, along with horizontal drilling and the increased price of oil
products, has made previously-inaccessible natural gas and petroleum resources
in “tight” or “unconventional” reservoirs producible in economic quantities. The application of these technologies has
greatly expanded U.S. oil and natural gas production over the past ten years.
Hydraulic
fracturing produces fractures in the rock formation through which the natural
gas or oil can flow. Wells may be drilled
vertically thousands of feet below the land surface and may include horizontal
or directional sections extending thousands of feet.
Fractures
are created by pumping large quantities of fluids (water, sand and chemical
additives) at high pressure down a perforated well casing and into the target
rock formation. Ninety-nine percent
(99%) of the hydraulic fracturing fluid commonly consists of water and
sand. The sand helps keep the fractures
open for the oil or gas to freely flow.
A number of chemical additives (about one percent of the volume of the
fracking fluid) are also added to the subsurface to reduce friction, prevent
iron, scale and corrosion and to control bacteria from clogging the formation.
These fractures can extend several hundred feet away from the wellbore. Figure 3.
Figure 3. Fracking
Schematic
During the completion
phase of an oil/gas well, fresh water is used to fracture the shale
formation. A typical multi-stage fracking
process uses at least 100,000 barrels of fresh water. When this water “flows back” it is salty and may contain the
injected chemicals plus naturally occurring materials such as brines, metals,
radionuclides, and hydrocarbons. The
flowback water
must be transported away from the drilling site and disposed of in a permitted
disposal well. The need for disposal of
flow-back water occurs only during the drilling of a new well, however flow-back
water disposal is often the second-largest expense of drilling a new well.
Water that comes to
the surface during the normal oil or gas production process is naturally
occurring briny water that is generated from deep within the earth along with
the oil and gas. This water is called
“produced water”. The need to dispose of
“produced water” is on-going and continues throughout the life of the oil/gas
well.
The
flowback and produced waters are typically stored on site in tanks or pits
before treatment, disposal or recycling.
In many cases, it is injected underground for disposal. In areas where that is not an option, it may
be treated and reused or processed by a wastewater treatment facility and then
discharged to surface water.
Other activities that
are part of the oil and gas production include, but are not limited to: increased
water usage, deforestation, dust, heavy truck traffic, blasting, sights and heavy
flood lights on a 24/7 operation, flaring and venting of the gases, compressor
stations for compression of the natural gas, storm water runoff, dehydrators,
condensate tanks and other storage, erosion of the cleared areas, high pressure
venting noises, loud gas flaring that emits pollutants into the air, and so on.
There
have many debates surrounding the regulatory exemptions for hydraulic
fracturing. It has been noted that if not for the exemption for hydraulic
fracturing in the Energy Policy Act of 2005 or the RCRA exemption that exempts
oil and gas waste from being designated as a hazardous waste, underground
injection would have included fracking operations, and the EPA would have had
the power to further regulate it as well as enforcing disclosure
requirements. Some say that these
exemptions not only create inadequate regulations but also provide incentives
for gas and oil companies to use chemicals that may increase the risks of
exposure to local communities. On the
other side of this, the oil and gas industry, Congress, and some environmental
groups support the idea that states, with greater knowledge about the local
economic and ecological landscape, should control the regulatory specificities
of fracking.
FRACKING ACTIVITIES
THAT CAN RESULT IN CONTAMINATION OF THE ENVIRONMENT
The biggest by far
problem is that many of these hydraulic fracking activities are exempt from
federal regulations or are loosely regulated regarding the handling of
hazardous or otherwise contaminated fluids or waste byproducts. The states are mainly responsible for
regulating these activities. Highly sophisticated
state regulators such as the NJDEP in New Jersey have placed a moratorium on
fracking; other states should take a hint from New Jersey. We believe that it is important to ensure
that the practice will not harm health, safety, air, land, water or water
security, considering the significant amounts of water required fro fracking.
·
Oil and natural gas wells flow back
water throughout their production lifespan, which produces a constant and known
demand for disposal.
·
The high pressures used to crack the
rocks can create fractures that can extend half a mile or more.
·
The drilling companies add biocides,
surfactants, flocculants, corrosion inhibitors, acids, etc. into the production
fluid to prevent the swelling of the formation clay (the shale) and the
self-sealing of the wells. Many of these
additives are not regulated or known.
·
The pit liners can tear or the pits
overflow due to hard to control fluids or piping/fittings brake resulting in
spillages. See Figure 3.
·
The spill containment facilities
maybe undersized or located in flood plains.
·
Very
little attention has been placed on the short-circuiting of the fracking fluids
through existing boreholes or through natural faults.
·
The
shale formation is not known (i.e., mapped) with much certainty, as the oil and
gas industry typically claims. These
rock formations have faults that are not known and where the fracking fluids
can enter and contaminate the subsurface.
·
Very
significant truck traffic, noise, lights, dust, compressor noise, flaring, air
emissions, and so on.
Figure 4. Lining and pit holding capacity issues
The point we want to make is that accidents happen in every
process. Hydraulic fracking is no
exception and impacts to the environment have already occurred and are bound to
occur in the future. Both the proponents
and the opponents need to get together to develop procedures that minimize the
damage to the human health and the environment when sudden or accidental releases
occur or releases caused by recklessness, negligence or other human errors.
Gas Sources
Methane
and other light hydrocarbon gases may originate through a number of different mechanisms
depending on the geologic environment.
These gases are formed by the decomposition of organic matter in the
absence of oxygen. In general, the gas
formation processes may generally be classified as either biogenic or
thermogenic. The biogenic gas is
concentrated at the shallower depths, with gradation with depth to thermogenic
origin. This classification of the gas
origin is important in determining the fate and transport of the gas during
fracking activities as it results in different gas composition, different
stable isotopic signature and different source.
Determination of the stable-carbon isotopic composition and the stable-hydrogen
isotopic composition generally makes it possible to distinguish methane formed
in natural gas from methane formed in landfills, or in coalbed gas or in
glacial drift gas or in shale gas.
Heavy isotopes get left behind during the
process of methane formation. Methane molecules formed both thermogenically and
bacteriogenically contain more light H and C relative to the source material
from which the methane was made (such as acetate, or organic material within
the shale). The amount of fractionation that has occurred is denoted with the
symbol “Ī“”. It should be noted however
that the processes of mixing of the various types of gases, migration of gas in
the subsurface and bacterial oxidation all have the potential to impede a clear
diagnosis of methane gas origin (i.e., whether it came from thermogenic gas due
to fracking) or it is a shallower bacterial-produced methane.
Potential Migration Pathways
Further
investigation is necessary to determine mechanisms of aqueous and gas phase
transport in the area of investigation. However, at least three mechanisms can
be postulated at this time. The first mechanism is aqueous and/or gas transport
via boreholes due to insufficient or inadequate cement outside production
casing.
The second
mechanism is fracture fluid excursion from thin discontinuous tight sandstone
units into sandstone units of greater permeability. This would be accompanied
by physical displacement of gas-rich solutions in both tight and more permeable
sandstone formations.
A third
mechanism is that the process of hydraulic fracturing generates new fractures
or enlarges existing ones above the target formation, increasing the connectivity
of the fracture system.
In all three
transport pathways, a general correlation (spatial relationships ultimately
determined by fault and fracture systems in addition to lithology) would exist
between proximity to gas production wells and concentration of aqueous and gas
phase constituents in ground water.
It is helpful to sample groundwater wells prior to
and during development of the shale gas wells. Only periodic sampling will help establish if
groundwater wells already containing entrained dissolved gas become contaminated
with gas from an adjacent oil and gas well.
What Chemical Additives Are Used
As
previously noted, chemicals perform many functions in a hydraulic fracturing
job. Although there are dozens to
hundreds of chemicals which could be used as additives, there are a limited
number which are routinely used in hydraulic fracturing. The following is a list of the chemicals used
most often. This chart is sorted
alphabetically by the Product Function to make it easier for you to compare to
the fracturing records .
Chemical Name
|
CAS
|
Chemical Purpose
|
Product Function
|
Hydrochloric Acid
|
007647-01-0
|
Helps dissolve
minerals and initiate cracks in the rock
|
Acid
|
Glutaraldehyde
|
000111-30-8
|
Eliminates
bacteria in the water that produces corrosive by-products
|
Biocide
|
Quaternary
Ammonium Chloride
|
012125-02-9
|
Eliminates
bacteria in the water that produces corrosive by-products
|
Biocide
|
Quaternary
Ammonium Chloride
|
061789-71-1
|
Eliminates
bacteria in the water that produces corrosive by-products
|
Biocide
|
Tetrakis
Hydroxymethyl-Phosphonium Sulfate
|
055566-30-8
|
Eliminates
bacteria in the water that produces corrosive by-products
|
Biocide
|
Ammonium
Persulfate
|
007727-54-0
|
Allows a delayed
break down of the gel
|
Breaker
|
Sodium Chloride
|
007647-14-5
|
Product
Stabilizer
|
Breaker
|
Magnesium
Peroxide
|
014452-57-4
|
Allows a delayed
break down the gel
|
Breaker
|
Magnesium Oxide
|
001309-48-4
|
Allows a delayed
break down the gel
|
Breaker
|
Calcium Chloride
|
010043-52-4
|
Product
Stabilizer
|
Breaker
|
Choline Chloride
|
000067-48-1
|
Prevents clays
from swelling or shifting
|
Clay Stabilizer
|
Tetramethyl
ammonium chloride
|
000075-57-0
|
Prevents clays
from swelling or shifting
|
Clay Stabilizer
|
Sodium Chloride
|
007647-14-5
|
Prevents clays
from swelling or shifting
|
Clay Stabilizer
|
Isopropanol
|
000067-63-0
|
Product
stabilizer and / or winterizing agent
|
Corrosion
Inhibitor
|
Methanol
|
000067-56-1
|
Product
stabilizer and / or winterizing agent
|
Corrosion
Inhibitor
|
Formic Acid
|
000064-18-6
|
Prevents the
corrosion of the pipe
|
Corrosion
Inhibitor
|
Acetaldehyde
|
000075-07-0
|
Prevents the
corrosion of the pipe
|
Corrosion
Inhibitor
|
Petroleum
Distillate
|
064741-85-1
|
Carrier fluid for
borate or zirconate crosslinker
|
Crosslinker
|
Hydrotreated
Light Petroleum Distillate
|
064742-47-8
|
Carrier fluid for
borate or zirconate crosslinker
|
Crosslinker
|
Potassium
Metaborate
|
013709-94-9
|
Maintains fluid
viscosity as temperature increases
|
Crosslinker
|
Triethanolamine
Zirconate
|
101033-44-7
|
Maintains fluid
viscosity as temperature increases
|
Crosslinker
|
Sodium
Tetraborate
|
001303-96-4
|
Maintains fluid
viscosity as temperature increases
|
Crosslinker
|
Boric Acid
|
001333-73-9
|
Maintains fluid
viscosity as temperature increases
|
Crosslinker
|
Zirconium Complex
|
113184-20-6
|
Maintains fluid
viscosity as temperature increases
|
Crosslinker
|
Borate Salts
|
N/A
|
Maintains fluid
viscosity as temperature increases
|
Crosslinker
|
Ethylene Glycol
|
000107-21-1
|
Product
stabilizer and / or winterizing agent.
|
Crosslinker
|
Methanol
|
000067-56-1
|
Product
stabilizer and / or winterizing agent.
|
Crosslinker
|
Polyacrylamide
|
009003-05-8
|
“Slicks” the
water to minimize friction
|
Friction Reducer
|
Petroleum
Distillate
|
064741-85-1
|
Carrier fluid for
polyacrylamide friction reducer
|
Friction Reducer
|
Hydrotreated
Light Petroleum Distillate
|
064742-47-8
|
Carrier fluid for
polyacrylamide friction reducer
|
Friction Reducer
|
Methanol
|
000067-56-1
|
Product
stabilizer and / or winterizing agent.
|
Friction Reducer
|
Ethylene Glycol
|
000107-21-1
|
Product
stabilizer and / or winterizing agent.
|
Friction Reducer
|
Guar Gum
|
009000-30-0
|
Thickens the
water in order to suspend the sand
|
Gelling Agent
|
Petroleum
Distillate
|
064741-85-1
|
Carrier fluid for
guar gum in liquid gels
|
Gelling Agent
|
Hydrotreated
Light Petroleum Distillate
|
064742-47-8
|
Carrier fluid for
guar gum in liquid gels
|
Gelling Agent
|
Methanol
|
000067-56-1
|
Product
stabilizer and / or winterizing agent.
|
Gelling Agent
|
Polysaccharide
Blend
|
068130-15-4
|
Thickens the
water in order to suspend the sand
|
Gelling Agent
|
Ethylene Glycol
|
000107-21-1
|
Product
stabilizer and / or winterizing agent.
|
Gelling Agent
|
Citric Acid
|
000077-92-9
|
Prevents
precipitation of metal oxides
|
Iron Control
|
Acetic Acid
|
000064-19-7
|
Prevents
precipitation of metal oxides
|
Iron Control
|
Thioglycolic Acid
|
000068-11-1
|
Prevents
precipitation of metal oxides
|
Iron Control
|
Sodium
Erythorbate
|
006381-77-7
|
Prevents
precipitation of metal oxides
|
Iron Control
|
Lauryl Sulfate
|
000151-21-3
|
Used to prevent
the formation of emulsions in the fracture fluid
|
Non-Emulsifier
|
Isopropanol
|
000067-63-0
|
Product
stabilizer and / or winterizing agent.
|
Non-Emulsifier
|
Ethylene Glycol
|
000107-21-1
|
Product
stabilizer and / or winterizing agent.
|
Non-Emulsifier
|
Sodium Hydroxide
|
001310-73-2
|
Adjusts the pH of
fluid to maintains the effectiveness of other components, such as
crosslinkers
|
pH Adjusting
Agent
|
Potassium
Hydroxide
|
001310-58-3
|
Adjusts the pH of
fluid to maintains the effectiveness of other components, such as
crosslinkers
|
pH Adjusting
Agent
|
Acetic Acid
|
000064-19-7
|
Adjusts the pH of
fluid to maintains the effectiveness of other components, such as
crosslinkers
|
pH Adjusting
Agent
|
Sodium Carbonate
|
000497-19-8
|
Adjusts the pH of
fluid to maintains the effectiveness of other components, such as
crosslinkers
|
pH Adjusting
Agent
|
Potassium
Carbonate
|
000584-08-7
|
Adjusts the pH of
fluid to maintains the effectiveness of other components, such as
crosslinkers
|
pH Adjusting
Agent
|
Copolymer of
Acrylamide and Sodium Acrylate
|
025987-30-8
|
Prevents scale
deposits in the pipe
|
Scale Inhibitor
|
Sodium
Polycarboxylate
|
N/A
|
Prevents scale deposits
in the pipe
|
Scale Inhibitor
|
Phosphonic Acid
Salt
|
N/A
|
Prevents scale
deposits in the pipe
|
Scale Inhibitor
|
Lauryl Sulfate
|
000151-21-3
|
Used to increase
the viscosity of the fracture fluid
|
Surfactant
|
Ethanol
|
000064-17-5
|
Product
stabilizer and / or winterizing agent.
|
Surfactant
|
Naphthalene
|
000091-20-3
|
Carrier fluid for
the active surfactant ingredients
|
Surfactant
|
Methanol
|
000067-56-1
|
Product
stabilizer and / or winterizing agent.
|
Surfactant
|
Isopropyl Alcohol
|
000067-63-0
|
Product stabilizer
and / or winterizing agent.
|
Surfactant
|
2-Butoxyethanol
|
000111-76-2
|
Product
stabilizer
|
Surfactant
|
One
of the problems associated with identifying chemicals is that some chemicals
have multiple names. For example Ethylene Glycol (Antifreeze) is also
known by the names Ethylene alcohol; Glycol; Glycol alcohol; Lutrol 9; Macrogol
400 BPC; Monoethylene glycol; Ramp; Tescol; 1,2-Dihydroxyethane;
2-Hydroxyethanol; HOCH2CH2OH; Dihydroxyethane; Ethanediol; Ethylene gycol;
Glygen; Athylenglykol; Ethane-1,2-diol; Fridex; M.e.g.; 1,2-Ethandiol; Ucar 17;
Dowtherm SR 1; Norkool; Zerex; Aliphatic diol; Ilexan E; Ethane-1,2-diol
1,2-Ethanedio.
This
multiplicity of names can make a search for chemicals somewhat difficult and
frustrating. However, if you search for a chemical by the CAS number it will
return the correct chemical even if the name on the fracturing record does not
match. For example if the fracturing record listed the chemical Hydrogen
chloride and you searched for it by name using a chemical search site you may
not get a result. But if you search for CAS # 007647-01-0 it might return
Hydrochloric acid which is another name of Hydrogen chloride. Therefore, by
using the CAS number you can avoid the issue of multiple names for the same
chemical.
Multiple
names for the same chemical can also leave you with the impression that there
are more chemicals than actually exist. If you search the National
Institute of Standards and Technology (NIST) ‡ website the alternate names of
chemicals are listed. This may help you identify the precise chemical you are
looking for. The NIST site also contains the CAS numbers for chemicals. NIST is
only one of many websites you can use to locate additional information about
chemicals. You can also search the following websites using the chemical name
or CAS number:
OSHA/EPA
Occupational Chemical Database ‡
The
Chemical Database ‡
EPA
Chemical Fact Sheets ‡
METROPOLITAN’S GAS MIGRATION INVESTIGATION AND
REMEDIATION EXPERIENCE
·
Investigated methane impacts at residential water
supply wells near a gas production well in Pennsylvania. The methane gas was found emitting from a
well in the vicinity of a gas well, posing an explosion and health hazard. Metropolitan performed a detailed review of
the regional and site specific geology, the construction of the gas well, and
performed a detailed review of the fracking and waste handling operations. The investigation revealed that the well was
located on top of coal seams; the coal seams would emit the coal-bed
methane. Isotopic analyses and detailed
composition analyses of the gases from the water well, the gas production well
and the coal seams indicated that the gas present in the water well was of
similar composition to that from the coal seams and different from the gas produced
at the gas well. The conclusions were
that the gas well was not the source of the methane inside the water supply
well. We also proposed and implemented a
mitigation strategy for the methane in the residential water supply well.
·
Investigated methane impacts at residential water
supply wells near a gas production well in New York. Metropolitan performed a detailed review of
the regional and site specific geology, the construction of the gas well, and
performed a detailed review of the fracking and waste handling operations. We also performed a video inspection of the
water supply well and determined that it was installed through coal beds. The coal seams would emit the coal-bed
methane. Isotopic analyses and detailed
composition analyses of the gases from the water well, the gas production well
and the coal seams indicated that the gas present in the water well was of
similar composition to that from the coal seams and different from the gas
produced at the gas well. The
conclusions were that the gas well was not the source of the methane inside the
water supply well.
·
Metropolitan provided litigation support for a large
number of litigation cases involving methane gas migration and intrusion, toxic vapor gas migration and intrusion
and petroleum hydrocarbon contamination involving refineries, bulk fuel oil
terminals, gas service station sites, oil and gas exploration sites and
brownfield sites.
·
Designed, installed and operated hundreds of
methane and vapor gas recovery or remediation systems at landfills, industrial
sites and brownfield sites.
·
For a confidential gas company,
served as a testifying expert on issues related to alleged groundwater
contamination from hydraulic fracturing activities. Work included reconstruction of baseline
groundwater condition prior to gas operations, tracking sources of organic and
inorganic compounds in groundwater, and tracking sources of dissolved and
gaseous methane using stable isotopes.
·
For gas production companies,
designed and implemented forensic field programs to differentiate native gas
from storage gas using composition and isotope analysis.
·
For gas companies, investigated
sources of natural gas bubbling in residential water wells. Used chemical fingerprinting including gas
composition and isotope analysis to determine the origin of the gas in the
water wells.
·
For a gas company in California and
Pennsylvania, investigated storage gas migration from a storage field. Using forensic and sampling results, calculated
the percentage of storage gas vs native gas in a number of gas wells located
near the leaking field.
·
Performed numerous field
investigations to determine sources of methane in soil and water wells underneath
newly constructed houses near brownfield sites.
Metropolitan Engineering, Consulting & Forensics (MECF)
Providing
Competent, Expert and Objective Investigative Engineering and Consulting
Services
P.O. Box 520
Tenafly, NJ 07670-0520
Tel.: (973) 897-8162
Fax: (973) 810-0440
E-mail: metroforensics@gmail.com
Web pages: https://sites.google.com/site/metropolitanforensics/
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