Natural Gas Drilling & Production  

Drilling 101

How are drillsites selected?

Drillsites are selected based on a number of factors: availability of land suitable to drill on; city permits; proximity to buildings, parks and other infrastructure; geologic considerations; proximity to natural gas pipelines or the feasibility of installing new pipelines; as well as the companies’ lease position in the area. Ultimately, energy companies strive to select sites that are least-intrusive to daily life.

How is it going to impact me?

From a physical standpoint, minor short-term disruptions may occur onsite, just like any typical urban construction project, but the majority of residents will experience few, if any, changes to daily life. The drilling is designed to have minimum impact on the environment and new pipelines pose no more danger than the common public natural gas lines that already service most neighborhoods. Economically, you will notice a big difference as natural gas production brings millions of dollars in revenue, new jobs and income streams to local property owners, municipalities and other taxing jurisdictions.

Where will the drillsite be located?

The goal of responsible energy companies is to find drillsites that allow safety and security at every location, to minimize disruption of the neighborhood, and to find access routes that are as unobtrusive as possible, while still able to produce the most minerals for their royalty owners, including school districts and municipalities.

How long will the drilling take?

From the time the pad preparation begins on a single drillsite, the entire process of setting up the rig, drilling, fracture stimulating (“fracing”) and installing operational equipment is usually six to seven weeks. Even with multiple-well padsites, the entire process frequently takes less time than building a house or store in the same area.

Watch a time-lapse video of the first well developed at the DFW Airport.

What times will the drilling activity take place?

During the approximately three weeks of drilling, operations run continuously 24 hours a day, seven days a week. The fracing may take three or four additional days and is restricted to daylight hours.

What impact will the drilling have on my neighborhood?

Today’s technology — and city code — ensures that drilling operations are sensitive to urban neighbors by restricting noise and light, controlling road access and providing security measures. As with any construction site, there will be additional truck traffic for setting up and taking down the equipment. After the wells are completed, the energy company returns to monitor and maintain the site. At some wellsites where piping isn’t an option, trucks may return to remove water from the tanks onsite.

What about the pipeline?

Pipelines are necessary to get the natural gas from the wellhead to market. While the diameter of the pipeline may vary depending on its function, they are all similar to normal utility pipelines that currently deliver gas to your home or office, and thus pose no elevated safety issues. New pipelines may be installed through traditional open trenching, boring underneath the ground, or a combination of the two.

What happens after the drilling?

Once drilling is complete and the operating equipment in place, urban wellsites are attractively fenced and landscaped. Because of that, they are frequently more appealing than other utilitarian structures like water pump houses or electrical stations. In many cases, the energy company makes other improvements to the area surrounding the drillsite, leaving it in better condition than when it was found.

What about truck traffic?

The water generated from natural gas production in the Barnett Shale must be either trucked or piped from the wellsite to an approved and licensed saltwater disposal well. Because the water output from a well drops significantly in just a short amount of time, the number of water trucks needed drops dramatically, as well.

On average, water output drops about 47 percent in the second week of production and 72 percent after 60 days. This, in turn, greatly reduces the number of trucks needed to transport the water to a saltwater disposal well. After three months of production, less than one truck per day per well is needed to carry water to a saltwater disposal well. After six months, this number drops to one truck per week per well and continues to decline over the life of the well.

I’ve heard about “hydraulic fracturing.” Why should I feel comfortable about this technique being used in the Barnett Shale?

Hydraulic fracturing or “fracing” is a technique in which fresh water is mixed with sand and non-toxic lubricants and injected at high pressure into the rock, fracturing it in order to release natural gas. Fracing techniques have evolved over time and vary widely in application, depending on the location and depth of the well and the type of sandstone, shale or other rock formation being fractured. In the Barnett Shale, the average depth at which fracing occurs is 6,875 feet, putting more than one mile of non-permeable rock between the freshwater table and the formation being fractured.

How can I be sure that the water table is protected during the drilling process?

The production of natural gas is highly regulated by the Railroad Commission of Texas (RRC). When a well is drilled, steel casing and surrounding layers of concrete are installed to isolate the well from drinking water aquifers through which the well penetrates. The depths at which this “surface casing” must extend are mandated by the RRC. In Barnett Shale operations, the surface casings are typically set to a depth of 1,200 – 1,300 feet, more than 400 feet below the Trinity Aquifer. After it is determined that the well can produce natural gas, additional strings of casing and tubing are set through the aquifers to provide even greater separation between the gas stream and the fresh water tables. The RRC also requires documentation of drinking water aquifer intervals, the design and installation of surface casing relative to those intervals, and the reporting of characteristics of the wellbore along with completion and production data. Other states have similar programs in place to protect drinking water resources.

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Water Management

Water Use in Natural Gas Production

How much water does the natural gas industry use in the Barnett Shale?

The entire amount of water used for all drilling and fracing operations in the Barnett Shale is between 0.5% and 2% of the total water used in this region. This data was acquired from a 2006 report from the Texas Water Board and a study conducted in 2007 by Dr. Peter Galusky of the environmental consulting firm Texerra and commissioned by the Gas Technology Institute. These water-use figures have been confirmed by various city water departments as well as the Tarrant Regional Water District, a major water supplier in the area.

Where does this water come from?

The sources for water in Barnett Shale vary, and much of the water used in operations comes from rivers, creeks, lakes, discharge water from industrial or city wastewater treatment plants and ground water. Water is often purchased from the city when drilling inside city limits and can be delivered through existing conduits, such as fire hydrants. All water must be metered and purchased regardless of the source. The public can rest assured that the gas industry would not use any community’s water supply to the point that it would cause hardship for local citizens, nor would they be allowed to do so by the local governing authority. The delivery of municipal water to gas companies would be curtailed more quickly than it would be to residential users. During periods of water restrictions, cities limit lawn and yard watering to particular times of the day for the purpose of conservation rather than rationing. These restrictions prevent waste by not allowing yards to be watered during the heat of the day, and evaporating before it soaks into the ground. 

Water Generated During Natural Gas Production

 What is hydraulic fracturing or “fracing”?

In order to release natural gas from the Barnett Shale which has low permeability, small cracks or fractures must be created in the rock — much like a windshield might be spidered or fractured if struck by a stone — to allow the gas to flow. “Fracing” is the process in which a mixture of sand, water and lubricants is pumped into the underground formation under high pressure to break open tiny fractures. These fractures are designed to release natural gas trapped inside the shale.

What is frac water, and how does it differ from flowback water?

In the Barnett Shale, frac water is the mixture of sand, water and lubricants used to fracture stimulate the well (see previous answer). During fracing, the water is exposed to the mineral deposits in the rock formation. After fracing, the water used for fracing the well flows back to the surface as “flowback” water. Because of its exposure to the minerals (primarily salts) in the formation, the flowback water gradually develops a higher salt content as it returns to the surface. Flowback water makes up only about 5% of the water from a Barnett Shale gas well. Produced water (see below) makes up the remainder of the water returned from a gas well. 

How much water is used to fracture stimulate a well?

For a typical well in the Barnett Shale, Chesapeake Energy uses about 3 million gallons of water in drilling and fracing operations.  In comparison, a typical golf course uses about 3 million gallons of water in just 10 days.

What chemicals are used in fracing?

About 98% or more of the fluid used in fracing consists of water and sand.  Other typical ingredients and their corresponding concentrations include:

(click on chart to enlarge view)

 What is produced water?

Produced water naturally exists in the Barnett Shale formation.  This water comes to the surface with the natural gas during production operations. Containing naturally occurring elements such as salt, produced water can have up to three times the chloride content of seawater and continues to flow throughout the life of the well.  The flow diminishes significantly over time, with water output dropping approximately 75% after 60 days.  Produced water makes up about 95% of the byproduct from a gas well in the Barnett Shale.

Salt Water Disposal

What happens to the produced water?

In the Barnett Shale, once produced water is separated from the gas, it is returned deep within the earth from where it came using salt water disposal  (SWD) wells, a type of Class II injection well used by the oil and gas industry. SWD wells are licensed and regulated for the disposal of water generated from the production of oil and gas. There are currently more than 50,000 Class II injection wells and over 11,700 active SWD wells operating in Texas.  Barnett Shale SWD wells are drilled into the Ellenburger formation, more than 1.5 miles below the surface, for the disposal of water generated from natural gas operations. 

What is the Ellenburger?

The Ellenburger is a porous rock formation which exists beneath the Barnett Shale.  Located about a mile and a half underneath the earth’s surface, this subsurface stratum already contains naturally occurring salt water, making it an ideal location to inject produced water from the Barnett Shale operations.  The span between the fresh water aquifers and the Ellenburger formation is made up of multiple layers of impervious rock, which prevent the injected water from migrating upward.

What measures are taken to ensure the safety of a salt water disposal well?

The Railroad Commission of Texas regulates disposal wells and their construction.  These regulations are the industry standard and are considered safe and effective.  Still, Chesapeake exceeds the Commission’s standards, constructing SWD wells with seven layers of protection in order to effectively isolate the water being injected from any drinking water aquifers.

1. Surface casing is run 150 – 200 feet below the deepest drinking water aquifer
2. A layer of cement holds the surface casing in place
3. Production casing runs through 1.5 miles of rock between the groundwater sands 
   and the Ellenburger formation
4. A layer of cement holds the production casing in place
5. A packer is installed at a level below the Barnett Shale (more than 7,000 feet below 
    the surface)
6. Steel tubing is added all the way down to the Ellenburger
7. An internal plastic coating is added to the tubing to prevent corrosion

In addition, more than 1.5 miles of impervious rock exists between the injected water and the fresh water aquifers, making it virtually impossible for any produced water to come into contact with these zones. 

The mechanical integrity of SWD wells is tested regularly, and the pressure in the well is monitored continuously to ensure that all of the disposed water reaches the Ellenburger formation. 

Why use Saltwater Disposal Wells?

Saltwater disposal wells are a proven technology.  The disposal of produced water through use of this technology is a monitored, safe and necessary practice which is overseen and inspected regularly by the Railroad Commission of Texas. 

“When wells are properly sited, constructed and operated, underground injection is an effective and environmentally safe method to dispose of wastes.”
                
                  — Environmental Protection Agency

“What is a way to safely dispose of millions of gallons of liquid waste per year from many manufacturing sites?

“In what way can millions of gallons of municipal sewage-derived liquid waste be disposed of without impacts to lakes, rivers or oceans?

“How can we dispose of, or even better, use billions of gallons of fluids from oil and natural gas production to help produce more oil?

“The answer to all of these questions can be summed up in two words: underground injection.”
                   – Groundwater Protection Council

Why use SWD wells & pipelines?

Strategically located SWD wells can reduce the miles trucks must travel in order to dispose of produced water. Connecting water pipelines from gas well sites to SWD sites would lessen truck traffic even more dramatically, reducing emissions, traffic noise, traffic congestion, road repairs, and improving the safety of the city.

Recycling Technology

Why can’t the water generated from natural gas production be recycled?

 Most of the water from natural gas production is too highly concentrated with naturally occurring minerals, such as salt, to be recycled effectively. There has been some success in recycling the first 5% of returned water, which is the frac or flowback water. However, by the end of the first week after fracing, flowback salt content can reach as high as 70,000 ppm, more than twice the salinity of sea water (30,000 ppm). At this time, the majority (95%) of the water returned from the well, with its high salt content, is too saturated to make recycling economically viable. Chesapeake and others in the industry are constantly evaluating opportunities to treat this produced water, so that less of it will need to be injected using SWD wells.

 Is Chesapeake employing any methods of recycling?

As part of a joint pilot project with the City of Fort Worth, Chesapeake is studying water evaporation systems as a potential way to reduce the amount of produced water being injected into SWD wells.  Using the heat generated by natural gas compressor stations — an energy source that would typically be wasted — the system filters and then evaporates a portion of the produced water.  The clean water vapor is then released into the atmosphere, where it will eventually return to the earth in the form of rain as part of the earth’s hydrological cycle. For more information on this technology, visit www.intevras.com/evras.html.

Water Transportation Options

What are the methods to transport the water generated from natural gas production?

Water from wellsites is either trucked or piped to salt water injection wells for disposal. Water trucks can transport between 5,000 to 6,300 gallons of water per load, depending on the size of the vehicle. Truck traffic, like the amount of water produced from well, drops significantly in a relatively short amount of time.  After three months of production, less than one truck per day per well is needed to carry water to an SWD well.  After 6 months of production, only one truck per week per well is required.

Use of water pipeline systems can further reduce the amount of trucks needed to travel to and from wellsites. Formed from polyethylene pipe, these systems are corrosion-resistant and contain monitored sensors at every well pad and no less frequently than every mile per pipe to ensure immediate response to potential leaks.

What measures are taken to ensure the safety of a salt water pipeline?

The pipeline used to transport produced water is made of corrosion resistant polyethylene and is nearly an inch thick.  Fused couplings are used to maximize leak protection, making the seams the strongest portion of the pipe.   Sensors are installed no less frequently than every mile to monitor the flow in the pipe, while state-of-the-art SCADA controls can be shut down immediately and remotely should a change in flow be detected.

References

Where can I find more information?

To learn more about the topics on this page, contact the following organizations:

Railroad Commission of Texas
www.rrc.state.tx.us
877-228-5740

U.S. Department of Transportation
www.dot.gov
202-366-4000

U.S. Department of Energy
www.eia.doe.gov  
202-586-8800

Intevras
www.intevras.com/evras  
512-538-2668

Natural Gas Regulations
www.naturalgas.org
202-326-9300

Code of Federal Regulations
www.ecfr.gpoaccess.gov  

U.S. Government Printing Office
202-512-0000

Environmental Protection Agency
www.epa.gov

National Response Center Hotline
800-424-8802

Clean Air Technology Hotline
919-541-0800

Barnett Shale Water Conservation & Management Committee
www.barnettshalewater.org 

Section last updated 12/04/08

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Pipelines and Compressor Stations

Paving the Way for Natural Gas

Pipelines and compressor stations are an integral part of natural gas drilling and production. Without pipelines, natural gas cannot be transported and sold at market to provide royalty payments, clean energy and the economic benefits to our community. And without compressor stations, natural gas cannot be moved through a pipeline network. Each element works safely in conjunction with others to complete the natural gas process.

Unfortunately, in the Barnett Shale there is a current shortage of pipelines and compressor stations. Due to the recent surge in natural gas drilling, a sufficient system for gathering and transporting the increased supply of natural gas being extracted from the Barnett Shale does not currently exist. Much like a highway in an area of town experiencing unprecedented growth, the current “roads” or pipelines available cannot accommodate the large volume of gas that needs to flow through them – so additional pipelines are needed.

Compressor stations first remove water from the natural gas, then bring the gas to the right pressure for safe and efficient transport through the pipeline network, converting the large amounts of gas derived from the Barnett Shale into a usable content. These stations can be quiet and non-invasive, similar to other public utility stations around town, which most people don’t even notice.

What is being done to make compressor stations urban friendly?

In urban environments, Chesapeake is implementing special sound abatement measures which dramatically decrease sound from compressor stations. Housed in new acoustical control buildings, these urban compressor stations are visually appealing and blend in with surrounding structures and buildings.

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The Pipeline Process: Start to Finish

Pipelines transport the valuable natural gas people need to heat their homes, power their appliances and cook their food. Yet, before the gas can be used in homes and businesses, there are three main steps that must happen to expedite its delivery. First, pipelines must be installed in the ground via trenching or boring. Trenching involves digging approximately six feet into the ground and laying the pipe. Boring involves drilling a horizontal hole (from three to 60 feet underground) and feeding the pipe into it. Next, gathering of the natural gas through a series of pipelines begins.

Gas is initially transported away from the well in a low-pressure pipe and then pushed to higher-pressure pipelines by a compressor station. Finally, the gas is transported to market for purchase, distribution and use. This process is the safest way to transport natural gas for ultimate use by consumers.

Once the pipelines have been properly installed and the process is complete, the land is reclaimed and restored or landscaped back to its original state. In fact, many of the parks and greenspaces you see every day already have pipelines running underneath them.

Why can’t we use existing pipelines?

In areas where appropriate pipelines already exist, natural gas companies make every effort to utilize them. Energy companies can share pipelines to transport natural gas if it maximizes value for royalty owners. However, there is currently an insufficient gathering system in place to accommodate the large volumes of gas being extracted from the Barnett Shale.

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A Mineral Owner’s Best Friend

Pipelines are the only feasible way to move natural gas. Without proper pipelines, natural gas cannot be transported. Royalties cannot be paid if gas is not transported and sold at market. This is extremely important since natural gas drilling has generated hundreds of millions of dollars in revenue and taxable income for North Texas.

And, like most facets associated with natural gas drilling, pipeline construction benefits the North Texas economy. Pipeline operations are directly employing thousands in Tarrant, Johnson and Dallas counties, and the new infrastructure serves to fuel local businesses in many ways. But these benefits reach far beyond fueling the economy. Pipelines facilitate a vital public need by helping to transport natural gas to end users: heating homes, fueling electric generation plants, powering automobiles and increasing U.S. energy security.

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Right-of-Way Agents: Working For You

Pipeline installation begins with a Right-of-Way Agent, who works with surface property owners and city planners to negotiate the planning, permitting, construction and completion.

First, the agent collaborates with energy companies to find the best place for the pipeline to be constructed. Then, the agent contacts the property owner to obtain an easement to lay the pipe in the least intrusive areas possible.

Once the proper easements and permits have been obtained, pipeline systems are constructed. The process is then completed as the pipeline installed from the well joins other gathering pipelines moving toward the compressor station.

If a pipeline is installed on or near my property, does that mean that I can never use that land again?

No. Surface amenities, including sidewalks, driveways, parking lots and shallow-root landscaping can still be constructed above pipelines. Though deep-root landscaping and permanent structures are not permitted on pipeline easements (to maintain the integrity of the pipeline and allow for safety inspection access), pipelines take up a relatively small amount of space. Companies work to honor property owners’ wishes by laying the pipes in the least intrusive areas. We also work to reduce the impact on landscaping when installing pipeline networks.

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Safety Matters

To ensure maximum safety, natural gas pipelines are highly regulated at both federal and state levels. Pipelines are governed by the Federal Energy Regulatory Commission (FERC), the U.S. Department of Transportation (USDOT) and the Railroad Commission of Texas (RRC). In fact, gathering lines are more highly regulated in Texas than any other state in the union. It is also worth noting that Chesapeake Energy goes beyond basic pipeline regulations to deliver the most reliable pipelines in the industry — we design our pipelines to even higher standards than required by the federal government.

Additionally, precautions and public awareness initiatives are taken to identify areas with pipelines to ensure that third-party digging never compromises the integrity of the pipe. Before any construction begins anywhere in the Barnett Shale, state law requires that anyone planning to dig deeper than 16 inches with machine-powered equipment must call DIG TESS (Texas Excavation Safety System) at 1.800.344.8377 at least two days in advance to ensure that current pipeline locations will not be disturbed. To learn more about DIG TESS, please visit www.digtess.org.

I’ve heard concerns about pipelines running underneath neighborhoods. Are they safe?

Most people do not realize that thousands of pipeline networks already exist and have been safely transporting public utilities underneath communities for years. Pipelines are essential to warm your water, heat your home and cook your food. Natural gas pipelines are simply delivering another product that is integral to your daily life.

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Safety Note

Regulatory agencies throughout the industry and the Barnett Shale are working together to guarantee that natural gas pipelines and communities continue to live in harmony. In the grand scheme of things, natural gas pipelines pose no more danger to citizens than any other public utility.

I want to know more about pipelines and compressor stations. What can I do?

Please refer to these additional resources for information on pipelines and compressor stations.

• Railroad Commission of Texas | www.rrc.state.tx.us | 877.228.5740
• Federal Energy Regulatory Commission | www.ferc.gov | 866.208.3372
• U.S. Department of Transportation | www.dot.gov | 800.877.8339
• U.S. Department of Energy | www.eia.doe.gov
• Environmental Protection Agency | www.epa.gov
• The Interstate Natural Gas Association of America | www.ingaa.org
• Natural Gas Regulations | www.naturalgas.org
• Code of Federal Regulations | ecfr.gpoaccess.gov
• Chesapeake Energy | www.AskChesapeake.com | www.chk.com | 817.870.1250
• DIG TESS | www.digtess.org | 800.344.8377

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Completed Drillsites

 After drilling is complete and the operating equipment is in place, Chesapeake's urban well sites are attractively fenced and landscaped. Because of that, they are frequently more appealing than other utilitarian structures like water pump houses or electrical stations. In many cases, the energy company makes other improvements to the area surrounding the site, which leaves the location in better condition than when it was found. 

Seismic Exploration

What is seismic exploration?

One of the biggest breakthroughs in natural gas exploration has come through the use of basic seismology. Seismology refers to the study of how energy, in the form of seismic waves, moves through the earth's crust and interacts differently with various types of underground formations. The thumper truck (pictured above), gently "thumps" the surface and sends soundwaves deep inside the earth that bounce back and are recorded by geophones.
The basic concept of seismology is quite simple:
A. The earth's crust is composed of different layers, each with its own properties. Energy (seismic waves) traveling underground interacts differently with each of these layers.

B. Transmitted from a source, these seismic waves travel through the earth, and are reflected back towards the source. Each underground layer reflects the waves in a different direction, depending on the makeup of the layer.

C. This reflection allows for the use of seismology to identify the properties of underground geology. Geophysicists are able to artificially create vibrations on the surface and record how these vibrations are reflected back to the surface.


The geophone (pictured above) records the soundwaves received from deep inside the earth.

How is seismic exploration used?
Using seismology for the exploration of natural gas involves artificially creating seismic waves, the reflection of which are then picked up by sensitive pieces of equipment called “geophones,” imbedded in the ground.

The data picked up by these geophones are then transmitted to a seismographic recording truck, which records the data for further interpretation by geophysicists and natural gas reservoir engineers. This information can be then analyzed to determine the locations of natural gas, as well as how to most effectively extract the gas.

How does 3-D seismic imaging work?
3-D imaging utilizes seismic field data to generate three dimensional “pictures” of underground formations and geologic features. 3-D seismic allows geophysicists and geologists to study the composition of the earth's crust in a particular area.

This is extremely useful in the exploration of natural gas, as an actual image can be used to estimate the probability of formations existing in a particular area and the characteristics of that potential formation. This technology has raised the success rate of exploration efforts. In fact, the use of 3-D seismic has increased the likelihood of successful reservoir locations by up to 50 percent.

By providing data about the location of natural gas reservoirs, 3-D seismic imaging ensures more accurate placement of drillsites and results in more productive wells.

                              

Environmental Health & Safety

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What chemicals are used in natural gas production?

 Chemicals used in natural gas production include:
 
Friction reducer — a lubricant that allows the fluid to carry frac sand into the formation 

Corrosion inhibitor — protects the metal casing against corrosion

Bactericide — prevents commonly occurring biological materials from beginning 
                     natural decomposition

Anti-freeze agent — used seasonally to prevent ice from forming
 
Used at low concentrations, these chemicals are no more toxic than many household items used by consumers daily.

How are chemical leaks prevented during drilling?

A number of redundant safety measures are in place to prevent chemical leaks. All fluids used in the drilling process are contained in a closed-loop system, which involves using a series of steel bins.

The design of the site also works to ensure that all liquid run-off is contained. At each site, a system of small diversion channels empty into a collection area, which is monitored and pumped out as the level rises.
 
Not only are any infrequent spills contained, but rain water run-off is also collected on location and then hauled off to make certain that nothing from the location impacts the surrounding environment.

What precautions are taken to prevent produced water spills at the site?

Once separated from the gas, the produced water is moved into tank batteries at the site. A metal barrier, which supports an interior liner that is impervious to leaks, surrounds the tank battery area at each wellsite, preventing the escape of produced water into the ground.Go to Top

How do you dispose of the produced water?

Produced water is transported by truck or by pipe to salt water disposal wells, where it is returned deep into the earth from where it came.
 
Salt water disposal wells, similar to gas wells, are constructed with layers of steel and cement. Seven layers of protection and ongoing monitoring at each wellsite ensure that salt water will not leak from the well into the water table.

More than 50,000 Class II injection wells are safely operating in the state of Texas.

What is the likelihood of a gas leak at the wellhead during the drilling process?

Until the well is completed, free-flowing gas is rarely encountered in the Barnett Shale because of its tight rock formation. Still, precautions are taken to prevent gas leaks from occurring.

Specialized equipment, such as a blow-out preventer, is installed and tested on every well to monitor pressure levels during the drilling process. An automatic alarm can sound if the pressure becomes too high or low.

I live very close to a wellsite. How do I know it’s not going to blow up?

Since the natural gas is not flowing during drilling, the odds of an offsite incident are slim to none.

Once a well is completed, pressure release valves are built into these systems to allow for the safe and controlled release of pressure, when needed, virtually eliminating possibility of an incident. Because natural gas is lighter than air, any released gas rises into the atmosphere and quickly dissipates, posing no harm to surrounding residents.
 
In Texas, there have been no reported resident or bystander injuries as a result of a wellsite incident.Go to Top

But I’ve seen news reports of houses blowing up from natural gas leaks. How can you say that a gas leak would not cause harm to nearby residents?

It is only when a gas leak is confined within a structure where it cannot escape, such as a house, that there is a cause for concern.
 
Three things — fuel, oxygen and an ignition source — are necessary for an explosion (combustion) to occur. Because of natural gas’ tendency to dissipate, the chances are extremely low that natural gas and oxygen would be present in concentrations that could cause harm. In addition, operators strive to eliminate ignition sources at the wellsite by using appropriate explosion-proof electronic equipment and lightning arrestors.

How will Chesapeake work with local authorities to manage an emergency situation?

Chesapeake will work closely with local authorities to resolve situation.

Chesapeake first responders will:

Control source to extinguish gas fire, if any
Work at well/rig site
Mitigate leaks by closing valves
Contain spills, preventing run-off to bodies of water

Local authorities will:

Provide fire suppression as appropriate 
Protect population
Protect collateral assets
Coordinate with operator
Use LEL meters to determine areas of concernwill work closely with local authorities to resolve situation. Go to Top

What emergency response plan is in place should an incident occur?

The risk of any problem beyond the actual padsite is extremely low. If an incident should occur, the natural gas industry works in close conjunction with the city’s emergency response team, just as any other industry is required to do in the case of an emergency.
 
The City of Fort Worth has a comprehensive response plan to respond to any emergency situation. According to information from the city’s website (www.fortworthgov.org), as emergency personnel arrive on-scene, the proper response actions are determined and then provided to the public. The actions are based on the situation and variables at the time. During non-emergency times, first responders develop possible scenarios and practice their response to ensure effectiveness and efficiency during an actual event.


 The recommended actions may be disseminated to the public through:
 
1. Sounding the outdoor warning system
 2. Local television and/or radio stations 
 3. The NOAA all-hazard radio
 4. Emergency personnel notification by going door-to-door 
     in the affected area

What amount of noise will be generated from drilling operations?

As with any construction activity, noise is a by-product. Our goal is to minimize the noise generated and to reduce the disturbance from drilling, which takes approximately three weeks per well. Chesapeake uses the latest technology to mitigate sound and not only fully complies with, but generally exceeds ordinance requirements.
 
The City of Fort Worth gas ordinance requires operators to establish ambient noise levels.  Drilling must not exceed ambient noise levels by more than five decibels during daytime hours and more than three decibels during nighttime hours.  Fracing operations may not exceed ambient noise levels by more than ten decibels.
 
On the other hand, train operations do not have these stringent sound ordinances, and have been recorded at 92 decibels during the day. In comparison, traffic noise emitted from 8th Avenue has been recorded at 85 decibels.Go to Top

How will CHK assure neighbors that you’ll go above-and-beyond to keep sound reduced during your drilling and fracing operations?

Chesapeake uses fit-for-purpose urban-designed rigs that are already quiet. Extra precautions are then taken to mitigate sound, using blankets around the engine, 16-foot sound walls around the site and additional mufflers as necessary. Based on a sound survey, experts determine the design and placement of the sound walls, which remain until all operations are completed.

How can we be assured of neighborhood safety from rig workers?

NOMAC conducts routine background checks and drug testing on rig workers when applying for a position, and continues to randomly screen during employment. Many drilling companies provide annual OSHA required training, and provide specialized training in operations and special equipment training.

Rig workers are highly trained in today’s technical, drilling process. The drilling crew is assigned to each rig on a permanent basis, so the same team stays with the rig from location to location and each worker is a well-known and trust member of the team. There are no transitory workers. Chesapeake has never had a report of urban neighborhood malfeasance from a rig worker.

What is the risk of injury or damage to the neighbors if an incident occurred at the wellsite?

There have been no reported injuries to any bystander or resident due to any well control incident in the entire state of Texas. Although the industry can be dangerous to rig workers, like any construction project, padsites are designed and constructed to contain potential spills or leaks onsite. Go to Top

What chemicals are found in saltwater that go into injection and disposal wells?

The overwhelming majority of injected fluid is oilfield brine, which is also called produced water. Oilfield brine is the salt water that is in the same geologic formations that produce oil and gas. This produced water comes up simultaneously with the production of oil and gas. However, small quantities of substances used in the drilling, completion and production operations of a well may be mixed in the waste stream. Some of these materials that may enter into the oilfield brine waste stream are minor amounts of drilling mud, fracture fluids and well treatment fluids. Also, since the produced water is associated with crude oil and natural gas, small amounts of residual hydrocarbons can also be found the produced water.Go to Top

What is a blowout and what practices are used to prevent or remedy such incident?

First of all, keep in mind that we encounter little to no gas while we are drilling the Barnett. The rock is so tight that free gas is not an issue. We do, however, take many precautions do deal with gas just in case.

A blowout is the term associated with a loss in control of oil, gas, or mud flow from a well. It is important to emphasize that there have been no reported injuries to any bystander or resident due to any well control incident in the entire state of Texas.

During the drilling process, the chance of a blowout occurring in the Barnett would be very rare since the shale formation is so tight that the escape of gas is virtually impossible. However, precautions are taken to prevent and to safely and expeditiously address any incident which could occur.

All wellsites are equipped with blowout preventers, or BOPs.  A BOP is a large valve at the top of a well that can be closed immediately if a change of pressure warrants it.  BOPs are critically important to the safety of the crew and are inspected, tested and refurbished at regular intervals.

In addition to BOPs, each rig is equipped with a pit volume totalizer, also known as a pit-level indicator, which continuously monitors the level of the drilling mud in mud tanks. If the mud level drops too low or rises too high, the alarm sounds to warn the driller of loss of circulation or a kick, which is a flow of reservoir fluids into the wellbore during drilling operations.

All supervisory level personnel on location are required to be certified in well control every two years.

In addition, lightning arrestors are in place at each wellsite just to prevent equipment from being damaged if lighting were to strike. Go to Top

What would be expected if the safety equipment was not utilized or malfunctioned?

The outcome would most likely result in a release of gas into the atmosphere.  Because natural gas is lighter than air, any released gas rises into the atmosphere and quickly dissipates, posing no harm to surrounding residents.

What equipment/practices are in place to immediately respond?

Each rig is equipped with two ram blow out preventers and an annular. Each is tested on every well. The equipment is function tested on every trip (at least once every other day). Each rig crew conducts a BOP drill at least once a week. We also utilize pit volume totalizer (PVT) equipment on each rig. The equipment is designed to help monitor the well for signs of a potential gas kick and it also helps avoid spills. All personnel with supervisor level positions on location (usually 3 at any given time) HAVE to be certified in well control every 2 years.

What safety statistics have shown the effectiveness of pipelines?

According to the safety statistics found on the PHSMA web site, www.phmsa.dot.gov, since 1988 there have been only 15 injuries resulting from gathering line incidents and no fatalities.  The average of significant incidents for the same timeframe is 11 significant incidents per year for all of the gathering lines in the United States.

What are pipeline companies doing to provide added safety?

Natural gas pipeline companies utilize corrosion inhibitors to protect inside of the pipeline.  Cathodic protection systems are also installed as directed by the Code of Federal Regulations Title 49 Part 192.  All of these systems must be monitored as dictated by the federal code.Go to Top

Are gathering and transmission pipelines odorized?

No, gathering lines are not typically odorized.  Distribution lines that are delivering gas to homes and schools are odorized to notify users if a burner tip is left on.  Gathering and transmission lines are inspected regularly and closely monitored for any drop in pressure.  These pipelines are held to heavier design standards that far outweigh the design standards of distribution lines.

Why are gathering lines not odorized?

Gathering lines are a closed system with control measures.  The lines are monitored closely for any drop in pressure and are inspected regularly.  At compressor stations there will be controlled venting of the gas.  The release of natural gas that is odorized would create concern for people in the area and would eventually compromise the sensitivity for the smell with natural gas customers.  Also, adding an odorant to natural gas too early in the production process can cause equipment problems for industrial users of the natural gas down the line and can make natural gas unsuitable for some market uses.

What federal standards are given related to pipeline odorization?

The federal rules for odorization of gas pipelines are given in 49 CFR Part 192.625, which details rules for the odorant chemical itself, what lines must be odorized, and, if odorization is required, rules concerning the equipment used for odorization and how often the odorized gas must be monitored for effectiveness.  Basically, all gas distribution lines must be odorized; and some gas transmission lines if the majority of the line length lies in highly populated (class 3 and class 4 areas) or if the transmission line terminates in these highly populated areas. Rarely are gathering lines odorized because they do not serve individual customers, because they do not transport "pipeline quality" gas, and they may not always flow gas in the same direction (odorization should occur upstream of affected areas).

Who has the power to regulate pipelines in Texas?

The Pipeline Safety Section of the Railroad Commission of Texas has safety jurisdiction over intrastate (within the state) distribution, transmission, and regulated gathering pipelines in Texas. The U.S Department of Transportation, Pipeline and Hazardous Materials Administration (PHMSA) has jurisdiction over interstate (crossing state boundaries) pipelines.Go to Top

How do authorities ensure compliance with these regulations?

 They employ inspectors, who periodically inspect or audit pipeline companies and their facilities for compliance with the regulations.

How often are pipelines safety audits conducted on?

RRC inspectors typically perform some type of audit annually, or more frequently if necessary, on pipelines which are in service.  The auditor may look at documents, records, or pipeline sites in the course of these audits, and interview responsible personnel.Go to Top

How do pipeline companies educate the public on safety?

The pipeline safety regulations require pipeline companies to have public awareness programs to help educate the general public, emergency responders, and excavators (those digging around pipelines) on the safety of pipelines, how to recognize a potential leak or problem, how to notify the company in case of a problem, how to recognize pipeline marking signs, etc.  This is accomplished through mail out of brochures, media advertising, participation in public meetings, and other means to meet these requirements.

What is the most common cause of pipeline damage?

The most common cause of pipeline damage is third-party digging.  “The Texas damage prevention law (Utilities Code Title 5, Chapter 251) took effect October 1, 1998. This law requires most facility owners to join a notification (or one-call) center and requires most excavators to call two working days before they dig.” (www.digtess.com)

What are pipeline companies doing to prevent damage from third-party digging?

Membership in one-call centers in all states in which the company operates, promotion in the use of these one-call centers, including the new nationwide “Call 811 Call Before You Dig Option,” and public awareness and education activities, as described previously.  Also pipeline companies may choose to meet face-to-face with contractors who have questions or may have damaged natural gas facilities in the past.

 Are the first responders educated about pipeline safety and incident control?

First responders are educated on these issues through public awareness programs, as described previously, and through meetings and training exercises usually offered by the companies individually.  Also, there is a training program directed at emergency responders to pipeline incidents available online from the National Association of State Fire Marshals (NASFM).

How are the first responders in the city notified of a pipeline incident?

Usually, the first responders are notified by a call from the general public or the pipeline company.Go to Top

What role do the first responders play in controlling incidents?

The first responders are involved with firefighting, evacuation of the general public, and crowd and traffic control.

What determines if a local area is to be evacuated due to a pipeline concern?

The extent of the problem determines the response.  The number one priority to responding to any emergency is protection of people first, then taking care of property and the environment.

What does it mean for a pipeline to be “pigged”?

Pigging is the act of inserting an inspection tool called a PIG or a device into a pipeline through a launcher, allowing it to travel down the pipeline with the gas and retrieving it at a downstream receiver. The PIG can perform any one of a number of functions with varied designs: cleaning, displacement, batching or internal inspection of the pipeline.  The pig can also be known as a scraper. “Smart” PIGs or “Smart” Tools can accurately detect and record size and location of corrosion pits or any other anomalies in pipelines.

What steps are taken to prevent pipeline corrosion?

Frequent pigging of the pipeline systems and injection of anti-corrosion chemicals into the gas stream prevents the pipeline from corroding on the inside. Devices are installed and used to monitor internal corrosion.  The outside of the pipe has an epoxy coating and cathodic protection to prevent it from corroding.

What is cathodic protection?

A method used to protect buried or submerged metal structures from corrosion using low-voltage direct electrical current.

Why is cathodic protection important to the pipeline, and how does it make the pipeline safer?

It stops the steel pipe from corroding on its external surface, which preserves the strength of the steel and keeps it from developing leaks.  Essentially, it prevents the metal from rusting.Go to Top

Does a valve site present a hazard to the public?

Under responsible operations, these sites are yet another safe component of the pipeline system.  The sites are typically secured with appropriate spacing from any sensitive surroundings.  Many similar locations already exist in the city but go unnoticed as part of the local distribution system.

What is MAOP?

MAOP is an acronym for Maximum Allowable Operating Pressure.  It is the maximum internal pressure that is permitted in the operation of a pipeline, as defined by the Code of Federal Regulations Title 49 Part 192.  The MAOP determined after considering multiple factors, such as pipe material, grade, pressure tests, operation, population density, and maintenance history.

Why is MAOP important?

MAOP is important because it is the maximum amount of pressure that the pipe is designed to hold.  If the MAOP is exceeded at any time, the operator must report that event to the Railroad Commission of Texas.

Should I be more concerned about a high pressure line than a low pressure line?

Not if the line is designed and installed properly.  Federal safety standards take the line pressure into account as part of the pipeline design.  These standards are more stringent as the pipeline’s designed MAOP crosses a certain threshold.  In the unlikely event that a high pressure line incurs a problem, it usually occurs in such a manner that the situation is immediately apparent due to the constant monitoring of the pressure in the lines.Go to Top

How do gathering lines compare to the distribution lines coming in my home?

Natural gas gathering lines are constructed of coated steel at high grades and thick walls, coupled with the use of cathodic protection and x-ray-tested welds. This makes the new pipelines often better than the distribution line which exists in your neighborhood. The materials used in some of the distribution systems reflect older (e.g., cast iron, copper, bare steel) as well as newer (e.g., polyethylene plastic and cathodically-protected coated steel) technologies. Two-thirds of states have programs that require distribution pipeline operators to replace older pipe, but much of the pipe in service is still many decades old.

What steps are taken to ensure the pipeline won’t leak and to double-check the material and construction?

To comply with the Code of Federal Regulations Title 49 Part 192, pipeline companies must x-ray and test their pipelines.  All of the welds are x-rayed to ensure integrity and after all components are installed, a hydrostatic test is conducted.  The pipe weld joints are then coated in the field with a fusion bonded epoxy, and the entire pipeline is inspected and any imperfections in the coating are repaired.

Where can I access incident reports and statistics for natural gas drilling and production?

The Railroad Commission of Texas (RRC) regulates oil & gas production within the state, as well as, establishes and enforces safety procedures for the industry.  All incidents are required by state law to be reported to the commission, as information of public record. The RRC website is www.rrc.state.tx.us. Go to Top

How are water zones protected until the well is cased?

Chesapeake has a state-of-the-art cementing and casing program that protects the aquifers from any drilling activities.  The hole is first drilled using fresh-water mud, which is a mixture of fresh water and bentonite clay. As the well is drilled, the clay actually plates out on the side of the hole, forming what is called a “wall cake,” preventing any migration of well bore fluid into the aquifer before it is cased.

Texas requires casing to be set at least 50 feet below the deepest freshwater zone, the location of which is determined by the Texas Commission on Environmental Quality.  Chesapeake’s engineers generally go about 150 feet below the deepest freshwater bearing zone as a precaution. The five layers of steel and cement which go into the construction of a natural gas well virtually eliminate the possibility of the contamination of any fresh water zones. Go to Top

What is H2S?

H2S is a naturally occurring gas primarily from the biological decomposition of older oil and gas fields, such as the Permian Basin area. As the field depletes its supply of oil, more decomposition occurs and concentrations of H2S increase. That is why a bactericide is added to natural gas wells, like using Formula 409 on kitchen countertops in your home to kill bacteria.

Do wellsites have an on-site fire suppression system, and if so, what does it entail?

As a precautionary measure, a foam line is installed outside the perimeter of the wellsite to aid firefighters in the event of an emergency. This line allows them to connect a hose that will pump foam into production equipment that will extinguish any problem without having to enter the site.

How does a large release of natural gas affect the atmosphere?

Natural gas already exists in the atmosphere. A gas release would have little to no impact to the atmosphere. Because of natural gas’ tendency to dissipate, the chances are extremely low that natural gas and oxygen would be present in concentrations that could cause harm.   Go to Top

What is flaring?

Flaring is a way to test the economic viability of natural gas wells. It’s completely safe, since gas in this area is lighter than air.

How is flaring done?

The gas comes out of the pipe, straight up, and is burned off to avoid any dissipation.

Why is flaring done?

It is usually done to test a well’s performance or quality when a pipeline is not available to flow the gas into. Many times a well will be flare-tested prior to making the decision to run an expensive pipeline to the well. (If the test results are not positive, then the well will be plugged.)

Is flaring safe?

When you see other companies flaring, please know that they have been required to obtain a permit from the Texas Railroad Commission, the regulatory agency for the natural gas industry in Texas, and that the process is well monitored. Responsible companies also alert city officials and neighborhood leaders before flaring is done to alleviate any concern. Flaring can last from 48 hours to a few days.

Does Chesapeake flare?

Chesapeake is one of the rare operators that does not generally flare in the Barnett Shale, and almost never in an urban setting. With our extensive pipeline network, we are generally able to hook the well to a gas line and test it. In most cases we are comfortable that the wells that we drill will be economically viable before we drill them and therefore will not require testing.

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What is coal-bed methane?

Coal-bed methane (CBM) is a naturally occurring gas found in coal formations that exist at depths of a few hundred feet to a few thousand feet beneath the surface, and is not generally found in the Barnett Shale.

How is CBM different from the natural gas found in the Barnett Shale?

CBM formations are often associated with drinking water resources because they generally occur at depths shallower than traditional gas reservoirs and are sometimes found in close proximity to freshwater aquifers. In contrast, the Barnett Shale formation is found more than a mile below the surface. This means that more than a mile of impermeable rock separates the drinking water aquifers from the zones at which natural gas production is occurring, providing a natural barrier of protection for the water table.

What is a sinkhole and how do they occur?

Sinkholes or cave-like structures can occur in other areas of the state and country where a certain type of rock or salt dome exists, which can dissolve over time by contact with water. Once the formation begins eroding, a sinkhole or cave may be created. Some natural geological wonders you may be familiar with include the Natural Bridge Caverns in south Texas or Carlsbad Caverns in New Mexico. The Texas Speleological Survey, a non-profit corporation established in 1961 to collect, organize, and maintain information on Texas caves, says there are no known sinkholes or caves located in Tarrant County.

Does drilling for natural gas create a cave or void?

No. People sometimes assume that when natural gas is extracted from below the surface, an empty space is created and this "space" will eventually cave-in. This way of thinking is inaccurate and does not apply to natural gas production in the Barnett Shale for several reasons. First, the shale or tight rock remains in place after the fracture stimulating process, therefore, there is no weakness created when gas is extracted. The 1.5 miles of impermeable rock that exists between the surface and the Barnett Shale makes it virtually impossible for a sinkhole to form in this region. Secondly, the rock or tight shale we are working in does not dissolve, regardless of any water that comes into contact with it. The shale is merely "cracked," which allows to gas to be released while the rock remains in place miles below the surface.