Presented by Jerry Strahan, P.E. Chief, Branch of Fluid
Minerals Bureau of Land Management Colorado State Office
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Introduction to Hydraulic Fracturing Shale Oil and Gas
Development Horizontal Drilling Fracking Process Environmental
Concerns Media and Fracking Information Questions
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A game changer Worlds major gas reserves: Qatar 1200 TCF Russia
400 TCF US Marcellus 300 TCF US Haynesville 250 TCF US Eagle Ford
(emerging) US Niobrara (emerging) Bakken Shale (N.D.) Largest US
oil discovery since Alaska at 3.6B bbls US is global leader in
shale technology & development and in proven gas reserves!
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What is Horizontal Drilling? Hydraulic fracturing is generally
associated with horizontal drilling practices. It is defined as
deviating the wellbore at least 80 degrees from vertical so that
the borehole penetrates a productive formation in a manner parallel
to the formation. Or simply drilling sideways. Source: ProPublica
http://geology.comhttp://www.oilandgasiq.com/glossary/horizontal-drilling/
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What is Hydraulic Fracturing? Well stimulation technique that
has been employed by the oil and gas industry since 1947. The
technique is used to create spaces in the rock pores deep
underground to release the oil and natural gas so that it can flow
to the surface. Fracturing fluids are injected at high pressure
into the targeted formation, creating fissures that allow oil and
gas to move freely from rock pores where it was trapped. Source:
ProPublica
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Typical Sanjel Hydraulic Fracture job set-up.
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http://hydraulicfracturing.aitrk.com/Process/Pages/information.aspx
Simplified Steps In Hydraulic Fracturing 1. Water, sand and
additives are pumped at extremely high pressures down the wellbore.
2. The liquid goes through perforated sections of the wellbore and
into the surrounding formation, fracturing the rock and injecting
sand or proppants into the cracks to hold them open. 3. Experts
continually monitor and gauge pressures, fluids and proppants,
studying how the sand reacts when it hits the bottom of the
wellbore, slowly increasing the density of sand to water as the
frac progresses.
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4. This process may be repeated multiple times, in stages to
reach maximum areas of the wellbore. When this is done, the
wellbore is temporarily plugged between each stage to maintain the
highest water pressure possible and get maximum fracturing results
in the rock. 5. The frac plugs are drilled or removed from the
wellbore and the well is tested for results. 6. The water pressure
is reduced and fluids are returned up the wellbore for disposal or
treatment and re-use, leaving the sand in place to prop open the
cracks and allow the oil/gas to flow. Simplified Steps In Hydraulic
Fracturing (Contd.)
http://hydraulicfracturing.aitrk.com/Process/Pages/information.aspx
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Why Hydraulic Fracturing and Horizontal Drilling? Combined with
horizontal drilling in shale formations, hydraulic fracturing has
unlocked vast new supplies of oil and natural gas. The technology
has also made production feasible in many areas that were
previously considered too deep, too hard, and too expensive to
access. The fracture paths created by hydraulic fracturing, and the
increased surface area exposed by horizontal drilling, can increase
production rates up to many hundreds of percent. Hydraulic
fracturing and horizontal drilling provide an environmental
advantage in that they reduce the amount of wells needed to
effectively drain an underground oil/gas reservoir. Less wells mean
less roads, less pipeline, less surface disturbance, etc.
http://geology.com
Illustration from EPAs Potential Relationships Between
Hydraulic Fracturing and Drinking Water Resources
presentation.
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Figure 2
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Figure 3
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Figure 4
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Figure 5
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Environmental Concerns Protection of groundwater and surface
water from contamination. Chemicals and additives in the fracturing
fluid. Large volumes of water needed for hydraulic fracturing.
Disposal of spent fracturing fluid (or flow-back fluid).
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Groundwater Protection Well integrity: Design and construction
of the well to ensure isolation in wellbore. Surface casing set
below useable groundwater and cemented to surface. Intermediate and
Production casing is cemented to isolate hydrocarbon zones,
providing further protection to groundwater. Multiple layers of
protective steel casing surrounded by cement. Cement Bond Logs
verify quality of cement job and centralizers placed on the casing
assures uniform cementing.
FRESH WATER AQUIFER ZONE SHALLOW PRODUCING ZONE INTERMEDIATE
PRODUCING ZONE CONDUCTOR PIPE SURFACE CASING PRODUCTION CASING
Subsurface Risks are managed by WELL CONSTRUCTION STANDARDS TARGET
PRODUCING ZONE
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FRESH WATER AQUIFER ZONE SHALLOW PRODUCING ZONE INTERMEDIATE
PRODUCING ZONE CONDUCTOR PIPE SURFACE CASING PRODUCTION CASING GOOD
MECHANICAL INTEGRITY: No leaks in or behind the casing strings
TARGET PRODUCING ZONE
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CEMENT CHANNELING behind production casing PRESSURE BUILDS UP
PRESSURE BUILDS UP CONDUCTOR PIPE SURFACE CASING PRODUCTION CASING
FRESH WATER AQUIFER ZONE SHALLOW PRODUCING ZONE INTERMEDIATE
PRODUCING ZONE TARGET PRODUCING ZONE CASING CEMENT FORMATIO N
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INSUFFICIENT CEMENT COVERAGE PRESSURE BUILDS UP PRESSURE BUILDS
UP CONDUCTOR PIPE SURFACE CASING PRODUCTION CASING FRESH WATER
AQUIFER ZONE SHALLOW PRODUCING ZONE INTERMEDIATE PRODUCING ZONE
TARGET PRODUCING ZONE
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LEAK THROUGH CASING CONDUCTOR PIPE FRESH WATER AQUIFER ZONE
INTERMEDIATE PRODUCING ZONE TARGET PRODUCING ZONE SURFACE CASING
PRODUCTION CASING FORMATIO N CASIN G SHALLOW PRODUCING ZONE
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CEMENT CHANNELING behind surface casing CONDUCTOR PIPE SURFACE
CASING PRODUCTION CASING FRESH WATER AQUIFER ZONE SHALLOW PRODUCING
ZONE INTERMEDIATE PRODUCING ZONE TARGET PRODUCING ZONE CASING
CEMENT FORMATIO N COAL SEAM (methagenic)
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FRESH WATER AQUIFER ZONE SHALLOW PRODUCING ZONE INTERMEDIATE
PRODUCING ZONE CONDUCTOR PIPE SURFACE CASING PRODUCTION CASING GOOD
MECHANICAL INTEGRITY: No leaks in or behind the casing strings
TARGET PRODUCING ZONE
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Environmental Concerns Protection of groundwater and surface
water from contamination. Chemicals and additives in the fracturing
fluid. Large volumes of water needed for hydraulic fracturing.
Disposal of spent fracturing fluid (or flow-back fluid).
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http://hydraulicfracturing.aitrk.com/Fracturing-Ingredients/Pages/information.aspx
Chemicals and Additives
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Water Viscosifiers Guar Gum, Cornstarch, Agar Oilfield Use
Thicken water for proppant (sand) transport Home Use Ice Cream
Gluten Free Baking Carpet Backing Petri Dishes Guar Bean
ClusterAgar Sea Vegetable Flakes
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Oilfield Use Thicken water for proppant (sand) transport Home
Use Laundry Detergent Fire Retardants Cosmetics Pesticides Slime
Crosslinkers Borax, a naturally occurring mineral
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Surfactants Oilfield Use Prevent oil and water from forming an
emulsion Cause oil and water to form an emulsion Foamers Degreasers
and Cleaners Home Use Bathing/Shampooing Salad Dressings Dust
Control Gardening Cleaning
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Disinfectants Bleach, Biocides Oilfield Use Control naturally
occurring bacteria or algae Home Use Drinking Water Treatment
Household Cleaners Swimming Pools
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Buffers Sodium Bicarbonate, Sulfamic Acid, Acetic Acid, Citric
Acid, Ascorbic Acid, Sodium Hydroxide Oilfield Use Adjusts the pH
of the frack fluid which affects the viscosity of the fluid Home
Use Baking Soda Remove Grout Haze Vinegar Oranges Vitamin C
Drano
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Breakers Hydrogen Peroxide, Ammonium Persulfate, Enzymes
Oilfield Use Causes gel to break down after sand is in place
allowing fluid to flow back to surface Home Use Septic Tank
Maintenance Manufacture of Circuit Boards Hair Bleaching
Disinfectant
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Iron Control Citric Acid, Ascorbic Acid, Acetic Acid Oilfield
Use Prevent rust which can lead to plugging of the formation Home
Use Lemons Vitamin C Vinegar
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Chemicals and Additives Wellbore integrity isolates fracture
fluids. Fluid flow-back adequately stored in lined earthen pits or
steel tanks until proper disposal. Material handling on surface is
in accordance with requirements and long-standing industry
practices. MSDS sheets available for review on well site.
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Environmental Concerns Protection of groundwater and surface
water from contamination. Chemicals and additives in the fracturing
fluid. Large volumes of water needed for hydraulic fracturing.
Disposal of spent fracturing fluid (or flow-back fluid).
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Water Volumes Typically,10,000-15,000 barrels per well
(420,000-630,000 gallons) are needed for fracture stimulation.
30-40% will flow back to surface. Use is temporary, not a long term
commitment. The amount of water that is used can be reduced when
fracture fluids are recycled. Other water use should be considered
with respect to current water uses (i.e. agricultural, municipal,
power generation, etc.).
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Environmental Concerns Protection of groundwater and surface
water from contamination. Chemicals and additives in the fracturing
fluid. Large volumes of water needed for hydraulic fracturing.
Disposal of spent fracturing fluid (or flow-back fluid).
Getting to the Bottom of FRACKING The truth is rarely pure and
never simple Oscar Wilde
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THE WALL STREET JOURNAL December 9, 2011 EPA Ties Fracking,
Pollution. Chemicals found in a Wyoming town's drinking water
likely are associated with hydraulic fracturing, the Environmental
Protection Agency said Thursday, raising the stakes in a debate
over a drilling technique that has created a boom in natural-gas
production.
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THE WALL STREET JOURNAL December 20, 2011 The EPAs Fracking
Scare the U.S. Geological Survey has detected organic chemicals in
the well water in Pavillion (population 175) for at least 50
yearslong before fracking was employed. There are other problems
with the study that either the EPA failed to disclose or the press
has given little attention to.
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THE WALL STREET JOURNAL April 1, 2012 EPA Backpedals on
Fracking Contamination The Environmental Protection Agency has
dropped its claim that an energy company contaminated drinking
water in Texas, the third time in recent months that the agency has
backtracked on high-profile local allegations linking natural-gas
drilling and water pollution. In addition to dropping the case in
Texas, the EPA has agreed to substantial retesting of water in
Wyoming after its methods were questioned.
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THE DENVER POST December 9, 2011 Hydraulic Fracking Linked for
First Time to Groundwater Pollution Hydraulic fracturing, a
controversial oil-and- gas production technique used in Colorado
and across the country, has been linked for the first time to
groundwater pollution in a case near Pavillion, Wyoming.
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THE DENVER POST June 18, 2012 EPA Results on Fracking in
Wyoming Continue to Confound But the findings on fracking while
suggestive and important are limited. Water supplies were not
contaminated by frack fluids and fracking did not turn out to be
the cause per se of the problems that prompted it the residents of
Pavillion to seek the EPAs help
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BOULDER DAILY CAMERA June 20, 2013 EPA Won't Confirm Fracking-
Pollution Tie in Wyoming The U.S. Environmental Protection Agency
announced Thursday it is dropping its longstanding plan to have
independent scientists review its finding that hydraulic fracturing
may be linked to groundwater pollution in central Wyoming.
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BLOOMBERG April 1, 2013 More Evidence Shows Drilling Causes
Earthquakes There have been a lot of earthquakes recently in parts
of the U.S. that traditionally havent seen so many, including
Arkansas, Texas, Ohio, and Coloradoall states where fracking
activity just happens to have increased substantially in the past
decade.
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BLOOMBERG April 10, 2013 Fracking Doesnt Cause Significant
Earthquakes, Study Says Hydraulic fracturing used to access oil and
gas from rock and shale hasnt caused significant earthquakes,
according to a study by Durham University. The size and number of
felt earthquakes caused by fracking is low compared to other
manmade triggers such as mining, geothermal activity or reservoir
water storage..
