Upload
dohanh
View
222
Download
3
Embed Size (px)
Citation preview
Horizontal Wells – Hydraulic Fracturingin Michigan
Michigan Oil & Gas Producers Education Foundation | 124 West Allegan St., Suite 1610, Lansing, MI 48933 | 517.487.1092 | mogpef.orgMichigan Oil & Gas Producers Education Foundation | 124 West Allegan St., Suite 1610, Lansing, MI 48933 | 517.487.1092 | mogpef.org
Introduction Since 1925, Michigan has been one of the nation’s
important sources of natural gas and crude oil.
Michigan’s natural gas producers supply 21.8
percent of the natural gas used by Michigan
residents and businesses for heating and energy
needs (U.S. Energy Information Administration,
2009). Natural gas is clean and abundant, making
it a reliable energy source for Michigan.
In Michigan, where renewable energy sources
like wind power are being developed to diversify
our energy mix, natural gas will continue to be a
major fuel source, as we bridge to a wider range
of energy sources in the future.
Home-state production of oil and gas benefits
our state, its communities, and families in many
ways. It supports energy security and independence,
provides thousands of Michigan jobs, and generates
millions of dollars in tax revenues for state and
public services. It also provides royalties that help
purchase land or support improved recreation and
environmental assets. Thousands of private mineral
owners – Michigan landowners – also receive royalty
income from production activities each year.
Hydraulic fracturing in MichiganHydraulic fracturing is a safe, proven and essential
process for recovering natural gas and oil from
reserves found deep below the earth’s surface
and often in tight rock formations, such as shale,
which are common to Michigan’s geology and
contain reserves of natural gas that are important
to Michigan’s energy supply.
More recently, production of natural gas and oil from
shale rock formations and other “unconventional”
sources has continued to grow as producers seek
opportunities to deliver more energy from onshore
domestic sources for meeting energy needs.
Michigan’s Utica/Collingwood, found at a depth that
ranges between 4,000 feet below the surface
of the earth (at the top of the lower peninsula)
to about 9,000 feet below the surface of the
earth, is an example of an unconventional source
formation that may have the potential to produce
significant energy.
Beginning in the 1950s, Michigan has a successful
track record of using hydraulic fracturing to safely
produce natural gas and oil from rock formations
deep underground. An estimated 12,000 producing
wells have utilized the method, while protecting
water resources and the environment.
Does hydraulic fracturing allow gas toescape into freshwater aquifers?No. With the appropriate well construction as required
by Michigan regulations, freshwater aquifers are
protected. Steel casings, and cement surrounding the
casings, isolate the well from surrounding freshwater
aquifers. There have been no reported occasions of
Michigan drinking water aquifers being affected by
fracturing activity, which has taken place in the
state for more than 60 years and in approximately
12,000 wells.
Why are some Michigan residents concerned about horizontal hydraulic fracturing?Michigan’s vast freshwater resources play a vital
role in our state, and Michigan residents rightly want
them protected. As awareness grows of the poten-
tial for enhanced gas and oil production in Michigan,
residents want assurance that water use by producers
will be reasonable, sustainable, and regulated, and
that water quality will be protected.
Recently, hydraulic fracturing has come under scrutiny
as media reports from other states have raised
concerns about environmental damage from disposal
methods in those states. In contrast, Michigan’s
strict standards for well construction and fracturing
fluid disposal are credited with the state’s strong
environmental safety record around oil and natural
gas production.
Why is horizontal hydraulic fracturing needed? Natural gas is critical to our energy supply, and
Michigan has large reserves of this clean and afford-
able fuel. The use of natural gas in Michigan is also
expected to grow, along side other renewable energy
sources that are being developed and will become
increasingly viable.
Hydraulic fracturing is essential to the successful
development of a large percentage of oil and gas
wells in Michigan. Many underground geologic
formations in Michigan have low permeability and
could not produce economically viable volumes of
natural gas without the use of hydraulic fracturing.
Horizontal drilling with the use of hydraulic fracturing
has important advantages in certain deep formations,
as the horizontal leg of the well exposes more of the
well to the producing formation and the fracturing
creates micro-fissures that allow natural gas or oil to
reach the well. It enables production of more natural
gas and/or oil from a single well. This makes
production from some deep reserves economically
viable, even with the immense development costs
of these wells.
Is more water used in fracturing horizontal wells than vertical wells?Water is necessary to conduct the hydraulic
fracturing process. The amount depends upon the
particular well, and the number of stages in the
fracturing process. Horizontal wells typically have
greater total depth, with fracturing taking place in
multiple stages. This generally requires the use of
more water for horizontal wells.
Can fracturing fluids find their way to groundwater?No, assuming proper construction of wells according
to state regulations. The fluids used in the fracturing
process are confined to the well and to the deep
formation being fractured. In Michigan, when the
fracturing fluids flow back to the surface through the
well, they are captured and stored in tanks before
being disposed of in regulated disposal wells.
What are the chemicals used in hydraulic fracturing? The fracturing fluid consists mainly of water and
sand. A small amount (less than 2 percent) of addi-
tives is used to ensure the water-sand mixture works
effectively in opening up rock fissures and enabling
gas or oil to flow to the well. Most additives are
those we encounter every day, such as disinfectants,
table salt, bleach, mineral oil and sodium carbonate
(used in water softeners).
Are drilling companies required to disclose the chemicals used in horizontal well hydraulic fracturing?Michigan regulations require operators to file Material
Safety Data Sheets (MSDSs) in compliance with OSHA
standards covering chemicals used in hydraulic
fracturing of horizontal wells. The Michigan DEQ posts
the MSDSs to its website for public disclosure. MSDSs
are also posted at each horizontal hydraulic fracturing
job site, and are made available to local first
response authorities.
Is hydraulic fracturing fluid ‘radioactive’?No. Fracturing fluid does not contain radioactive
qualities when it is pumped into the ground via a well,
nor when it comes back to the surface. All fracturing
fluids are disposed of in United States Environmental
Protection Agency (EPA) and Michigan DEQ regulated
disposal wells.
Is it possible that tap water from ahousehold faucet could catch fire, as has been reported?Gas occurs naturally in some fresh water aquifers
or surface waters. In rare situations, where flamma-
ble tap water occurs, the cause is usually naturally
occurring methane gas in the residential water well,
not hydraulic fracturing operations. In a few in-
stances in other states, gas has migrated into
aquifers due to improper well construction unre-
lated to hydraulic fracturing. Michigan’s well con-
struction standards prevent this type of occurrence.
Can hydraulic fracturing be done safely?Yes, with proper well construction as required by
Michigan regulations, and proper disposal of waste
fluids. Michigan has a program for ensuring proper
disposal. In Michigan, fracturing fluids are disposed
of in regulated disposal wells.
Is horizontal hydraulic fracturing occurring in Michigan? Hydraulic fracturing of horizontal wells has been and
is being conducted in Michigan in several geologic
formations. More recently in Michigan, some
producers are assessing the Utica/Collingwood as a
potential significant source of natural gas, as well as
its economic feasibility and the need for this addi-
tional energy source for individuals, businesses, and
manufacturers. Development, if it occurs on a signifi-
cant scale, is expected to involve deep horizontal
wells of greater length, utilizing multi-stage fracturing
to access greater reserves of energy.
What is Michigan’s experience with hydraulic fracturing and horizontal drilling?Hydraulic fracturing has been used in Michigan
since the 1950s, in more than 12,000 wells. More
commonly, a straight vertical well has been used;
horizontal wells — where the vertical well reaches its
depth and then is extended horizontally underground
— is an approach being used by producers where
appropriate to the producing formation. The approach
used depends upon the geologic conditions and the
economic reality of a particular situation.
Increased demand by citizens for clean burning
natural gas and greater energy independence, and
the potential opportunity for greater natural gas
production from Michigan’s abundant resources,
suggest that horizontal drilling could play a beneficial
role in future production, while boosting job creation
and economic growth.
How is horizontal hydraulic fracturing regulated? Michigan oil and gas production, including hydraulic
fracturing, is strictly regulated. Regulations govern
well construction, drilling sites, environmental
monitoring, hydraulic fracturing, and waste
fluid disposal.
How is hydraulic fracturing fluid disposed? In Michigan, used fracturing fluids that flow back to
the surface after the fracturing process are disposed
of in U.S. EPA and Michigan DEQ regulated
disposal wells.
More recently, production of natural gas and oil from shale rock formations and other “unconventional” sources has continued to grow as producers seek opportunities to deliver more energy from onshore domestic sources for meetingenergy needs. Michigan’s Utica/Collingwood is anexample of an unconventional source that may have the potential to produce significant energy.
MOGPEFMOGPEF
Michigan Oil & Gas Producers Education Foundation – Exploring Oil and Natural Gas through Education
Answers to Commonly Asked Questions
Antrim Shale: Counties in which exploration and production have predominantly occurred.
Utica/Collingwood: Counties in which exploration has occurred.
September 2011
Each well drilled in Michigan is constructedwith the protection of the environment andwater resources in mind, and in accordancewith regulatory requirements.
Michigan has taken prudent steps tostrengthen its regulatory framework.Michigan fosters energy production while maintaining a clean environment.
IMPERVIOUS ROCK LAYERS
Surface Casing*
Cement
Production Casing
Cement
HydraulicFracture Area
FRESH WATER AQUIFERS
Intermediate Casing
Required to 100 feetbelow deepest potentialfresh water zone
*
Cement
Michigan regulatory effectivenessWhen it comes to experience and safety in the
natural gas and oil exploration and production
industry, Michigan is a leader. With its own
experience, as well as that of other states,
Michigan has taken prudent steps to
strengthen its regulatory framework. Michigan
fosters energy production while maintaining
a clean environment.
In May 2011, the Michigan Department of
Environmental Quality (DEQ) announced
additional regulations for the gas and oil
industry to provide disclosure and trans-
parency related to larger-volume hydraulic
fracturing activities in Michigan.
New requirements for larger-volume
hydraulic fracturing include:
• Changes to water usage oversight –Operators must document where they
are getting the fresh water used in the
process, using the DEQ's water withdrawal
assessment tool to ensure that neither
surface water nor any neighboring water
wells are adversely impacted. They must
also report the total volume of fracturing
water recovered during operation.
• Reporting – The DEQ requires operators to
file Material Safety Data Sheets (MSDSs) in
compliance with federal Occupational
Safety and Health Administration (OSHA)
standards, and the DEQ will post that
information on the department's website
for public review. The MSDSs list character-
istics of chemical additives and their
potential health effects.
• Fracturing records – Operators must submit
service company fracturing records and
associated charts showing fracturing
volumes, rates, and pressures.
Deep horizontal wells: access to more energy, more efficiently,less impactFederal and state regulations affecting well
construction, drilling sites, environmental
monitoring, and waste fluid disposal strictly
regulate hydraulic fracturing in Michigan.
Horizontal drilling, coupled with multi-stage
hydraulic fracturing, has many advantages
for accessing gas and oil located in certain
deep formations. The approach:
• Makes production from certain deep
reserves economically viable, even with
the immense development costs, because
the resulting micro-fissures allow signifi-
cant volumes of oil or gas in tight rock
formations to reach the well.
• Enables a single well to produce from an
extended area, with the surface facilities
located in one location.
Vertical and horizontal wellsWhether the well is a vertical well or
horizontal well, the purpose and method of
fracturing is the same. The purpose is to
create fissures — or pathways — that allow
sufficient quantities of oil or gas locked in
the rock to move to the well, thereby making
production economically viable. All wells
require these pathways; hydraulic fracturing
in tight rock formations (where the pathways
do not occur naturally) allows producers to
create the pathways necessary for oil or gas
to move more freely from the tight forma-
tions. Fracturing may be conducted in one
stage, or in multiple stages, depending on
the specific circumstances of the well
and the reservoir formation.
Vertical wellsIn Michigan, vertical wells are most com-
mon, as producers have developed energy
reserves from reservoirs that can be
efficiently produced through vertical wells.
Vertical wells extend straight down from
the earth’s surface to reach formations
containing gas and/or oil reserves.
Horizontal WellsA horizontal well is a vertical well with a
horizontal leg, or a lateral extension, that
stretches out within the deep productive
formation. Horizontal wells have been com-
mercially used in Michigan since the 1980s.
Hydraulic fracturing in horizontal wells uses
the same process of fracturing as used in
vertical wells. Where the horizontal leg is
extended, the hydraulic fracturing process
is typically conducted in several stages along
the length of the leg. This creates micro-
fissures along the horizontal leg of the well,
allowing a single well to produce from a
larger area within the producing formation.
Fracturing — whether in a single stage or
multiple stages — takes place in a regulated,
well engineered and controlled procedure.
The opportunity for increased production to
meet energy needs and reduce dependence
on foreign energy sources, by using clean-
burning natural gas, could spur development
of deep shale and other unconventional
sources in Michigan, such as the Utica/
Collingwood. Such development could utilize
longer horizontal wells and multi-stage
hydraulic fracturing. If efforts to develop the
Utica/Collingwood using longer horizontal
wells are successful, another positive aspect
would be the relatively low surface impact
of a single well producing from a large area
within the underground formation.
Safety and responsibility Well constructionFracturing operations in Michigan take
place in an oil and gas-producing zone
below the freshwater aquifers. Each well
drilled in Michigan is constructed with the
protection of the environment and water
resources in mind, and in accordance with
regulatory requirements.
Typical Utica/CollingwoodHorizontal Well In MichiganHydraulic fracturing is not a drilling method.
After a well has been drilled, hydraulic fracturing
involves pumping water, sand, and a small
amount of additives down the well under
controlled pressure. As the mixture is forced
out through perforations in the well casing and
into the surrounding rock, the pressure causes
the rock to fracture – creating micro-fissures
that enable gas and/or oil to flow from tight
or low permeability rock to the well.
Steel surface casing is set from the earth’s
surface down to a depth 100 feet below
the deepest potential fresh water zone, and
cemented to the surface. Utica/Collingwood
horizontal wells in Michigan also have an
intermediate casing extending up to half the
vertical well depth, providing additional protection
against potential gas migration. Finally, production
steel casing is set deeper into the production
zone and through the horizontal leg and
cemented, ensuring the protection of ground-
water by multiple cemented steel casings.
Sand Keeps Fissures Open
FissuresPerforation
Gas Flows From Fissures Into Well
Well
Graphic is not necessarily to scale.