Natural Gas Pipelines  

Pipeline 101

Are natural gas pipelines a new way to transport gas?

No, but the technologies associated with pipeline design, construction, and installation have improved tremendously through the years.

How does the U.S. Department of Transportation classify pipelines?

The U.S. DOT classifies pipelines under two separate categories – classifications and transportation lines.

For design purposes, there are four classifications, or class locations, of pipelines. The choice of which class to use depends on the proximity of the pipeline to inhabited buildings along the pipeline’s route. Class 1 is typically used in rural areas; Class 2 and 3 are more suburban in nature; and Class 4 is where four-story or taller buildings are prevalent in the area.The U.S. DOT also classifies pipelines as distribution, gathering or transmission lines. 

Gathering lines typically transport gas from production sites (wells) to other gathering or transmission lines. Transmission lines are large diameter pipelines that operate at high pressure to transport gas cross country to gas distribution systems and large customers like power plants that generate electricity. Distribution systems are the network of pipelines that distribute gas through main lines and service lines to the ultimate residential or commercial customer.

What is a common carrier?

Section 111.002 of the Texas Natural Resources Code defines a common carrier as a person who owns or operates a pipeline that carries crude petroleum, coal, carbon dioxide, hydrogen, or the products of carbon gasification.  The definition of common carrier does not include an owner or operator of a pipeline that carries natural gas.

What is a gas utility?

Texas statutes contain various definitions of the term gas utility for use in numerous statutes. The definition that is most applicable to distinguishing a gas utility from a common carrier is found in Texas Utilities Code 121.001, which is titled Definition of Gas Utility. The second category, described in subsection (a)(2), applies to midstream pipelines that do not sell gas to the public. That subsection defines a gas utility as a business that: (2) owns, operates, or manages a pipeline:                                  

    (A)  that is for transporting or carrying natural gas, whether for public hire or not; and
   
    (B)  for which the right-of-way has been or is hereafter acquired by exercising the
          right of eminent domain…

What rights are given to a gas utility?

The status of gas utility imposes burdens more than it grants rights. The status of Gas Corporation gives several rights to a company to own and hold property, to build and maintain facilities, and to exercise the right of eminent domain. If a gas corporation uses the right of eminent domain to acquire right-of-way, it becomes a gas utility, but its right of eminent domain comes from its status as a gas corporation, not its status as a gas utility.Go to Top

What is the most common designation for the gathering pipeline companies in this area?

The most common designation for the pipeline companies in this area is a gas utility.

Are you required to accept the gas of other companies?

Yes, a gas utility must accept third party gas if the pipeline has the volume and if the third party will pay a defined rate.

Where is this natural gas going?

Natural gas from the Barnett is initially delivered to markets around the state.  The most common markets are Carthage (East Texas), WAHA (West Texas), Houston Ship Channel and Katy (South Texas).

What will it be used for?

Natural gas is a high demand product used in electric generation, industrial use, residential heat and even automobile power.

How does a pipeline company move its gas out of the local area?

There is a “highway” of pipelines which gather and transport gas from the local area to various markets or hubs around the country where the gas is typically sold to a marketing company or end user.

What are some of the transmission companies out there?

Some well known pipelines include Energy Transfer, Crosstex, Atmos, Enterprise and Enbridge. 

How does natural gas production in Texas compare to the rest of the country?

According to the U.S. Energy Information Administration, in 2006, Texas produced more than 5.1 trillion cubic feet of natural gas.  Texas production far exceeded any other state with 27.8 percent of the total production in the United States.
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How many miles of natural gas pipeline exist in the United States? In the State of Texas?

Total natural gas pipeline mileage in the continental United States exceeds 301,965 miles.  Texas leads with more than 57,519 miles of existing natural gas pipeline.  These statistics can be found on the U.S. EIA website at www.eia.doe.gov.

What safety statistics have shown the effectiveness of these 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.

How many pipelines like these will there be in the city?

This is a function of the drilling activity.  Each well pad will require a pipeline connection in order for gas to flow.

How does the city become involved when a pipeline crosses a street or utility?

Section 181.005 of the Texas Utilities Code gives a gas corporation the right to go along or across a street or road, but Section 181.006 says that a gas corporation can exercise that right inside a city with the consent and subject to the direction of the governing body of the city.

What legal rights does the city have to control this pipeline?

The city has the right to keep the pipeline from damaging or unreasonably interfering with the street, the right to coordinate the use of the street by all utilities with the right to use it, and the right to require the pipeline company to relocate the pipeline at company expense if the relocation is necessary to widen the street or road.

Can the city receive a map of the route before it is acquired?

Filing a map with the city before a pipeline route is ready to be constructed could create a multitude of issues because the proprietary information would become public.  First and foremost national security would be compromised as the exact location of the pipeline would be publicized.  In the State of Texas, pipeline locations are permitted and filed with the Railroad Commission of Texas. 

What type of gas is typically found in the Barnett Shale?

The natural gas found in the Barnett is mostly methane gas with a low percentage of other gases or hydrocarbons.  The Barnett gas also contains some amounts of entrained water vapor which is comparable to heavy humidity in the air.
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Does the gas rise when exposed to the atmosphere?

Yes.  Methane gas is 40% lighter than air and has a natural tendency to dissipate.

What are pipeline companies doing to provide added safety around this gas?

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.

Does natural gas smell?

The natural gas found in the Barnett Shale has no odor in its natural state.

What makes my natural gas line at home smell?

A chemical called mercaptan is added to the natural gas to create a distinct odor for identification and leak detection purposes.

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).Go to Top

Who has the power to regulate these pipelines in the state?

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.

How do they 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 do they conduct these audits?

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.

Does the RRC really have the number of people to ensure the safety of these pipelines?

As reported by the Railroad Commission of Texas, state pipeline safety personnel represent more than 80 percent of the state/federal inspection workforce. 

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How will the public be educated on pipeline 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 from occurring?

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 in the city 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 Marshalls (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.

What role do the first responders play in controlling this incident?

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

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 is the pipeline company doing to be sure this pipeline doesn’t corrode?

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.

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.

How often is pigging done?

“Smart” PIGs or “Smart” Tools can accurately detect and record size and location of corrosion pits or any other anomalies in pipelines. Go to Top

In the Barnett, what products are usually collected by a PIG?

Most commonly found in the Barnett has been produced water, mill scale and debris such as sand or grit.

What is a valve site?

An above-ground section of the pipeline where valves or other appurtenances (i.e. PIG traps, measurement skids, etc.) are installed to allow sections of the pipeline to be periodically taken out of service for inspections and maintenance.

Why is a valve site needed?

These sites are needed to have room to install, access, and operate the abovementioned appurtenances as well as maintain the pipeline.

Are they required or is this something the pipeline company chooses to do?

Both.  In the case of Mainline Block Valves, there are regulatory drivers that mandate block valves at certain intervals along the pipeline.  The company may install valves more frequently in certain instances in order to improve response time.  In other cases, pigging facilities are needed for pigging and inspecting the pipeline.

How large are valve sites?

The sites vary greatly in size depending on the size of the facilities required within.  An individual valve site can be as small as 400 square feet.  Valve sites are also located at compressor stations where several acres may be used.

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.Go to Top

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.

What pressure does a gathering line operate at and why is this important?

This is dependent upon the characteristics of the field from which gas is gathered.  Line pressure is an important factor impacting the deliverability of pressure dependent reservoirs (those reservoirs that produce more gas with lower line pressures).  The Barnett Shale is one of those reservoirs that generally does not produce against line pressures much in excess of 400 psig (pounds per square inch gauge) and may produce at a higher rate against lower line pressures.

What pressure does a transmission line operate at and why is this important?

This is highly variable based upon the location, age, and materials (among other factors – see the discussion regarding MAOP) of the pipeline.  Generally this is in excess of 600 psig and commonly is in excess of 1,000 psig but usually below 1,480 psig.  Gas is transported more efficiently at higher pressures (less energy is consumed per unit of distance). 

What is the typical thickness and grade used in the Barnett Shale?

It depends on the diameter of the pipe.  Many industry gathering lines are typically designed for an MAOP of 720 psig, so they must consider a match of pipe diameter, wall thickness, and grade to result in the desired MAOP.Go to Top

How does that 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.

How do federal regulations address wall thickness and steel grade?

The design formula for steel pipe in the federal regulations is calculated using pipe diameter, wall thickness, and grade (based on the strength properties of the steel) as variables. Also, the class location of the pipeline has an associated design or safety factor which must be taken into account when designing the pipe.

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. 

How is a pipeline constructed?

There are basically three methods of constructing a natural gas pipeline – conventional boring, horizontal directional drilling and trenching.

•    A conventional bore is commonly used to cross under roads. Boring pits are 
     dug on each side of the crossing. On the inlet side, a boring machine with an
     auger typically is used to create the bore hole, through which the pipe is strung
     until it reaches the other side of the crossing. 

•    Horizontal Directional Drilling is a trenchless construction method utilizing
     equipment and techniques from horizontal oil well drilling technology and
     conventional road boring. HDD construction is used to install natural gas pipelines
     when open trench construction is not feasible or will cause adverse disturbances to
     environmental features, land use or physical obstacles. The construction of the
     pipeline will have little to no surface impact on the property under which the bore
     will cross. Construction bore sites will be located at both ends of the bore where
     the construction equipment will be used and the pipeline will be installed.

•    The trenching method of pipeline construction involves digging a trench in which the
     pipeline will be buried at a minimum depth of 3 feet. During trenching, the excavated
     soil is piled on one side of the trench and used for backfilling after the pipe is
     installed in the trench.

What factors determine the construction method of the pipeline?

Several factors are considered when choosing the method of construction for any length of pipeline.  Environmental features, surface appurtenances, public impact, as well as constructability all play an intricate part in choosing the construction method.  Typically, the trench method of construction requires a 40-foot to 70-foot wide workspace adjacent to the pipeline easement.  The workspace varies depending on the size of the pipeline.  Where construction space is limited along the pipeline route or environmental issues dictate, the HDD bore may be utilized.  While the adjacent workspace is eliminated on and HDD bore installation, large amounts of workspace are needed at the beginning and end of the bore to allow room for the construction equipment and pipeline to be connected before installation.Go to TopGo to Top

How long does it take to install a pipeline?

Pipeline construction is affected by weather and existing circumstances just as any form of outdoor construction.  A typical trench construction project takes approximately two weeks per mile of pipeline.  An HDD bore method of construction typically takes four weeks per mile of pipeline.

What hours of the day are you constructing the pipeline?

Typically pipelines are constructed 10 to 12 hours a day, seven days a week.

What are the federal and state regulations on pipeline construction?

Pipeline construction regulations are stipulated by the Code of Federal Regulations Title 49 Part 192.

How often are these standards reviewed?

The construction standards are not reviewed on a set schedule, but these regulations have been amended over 100 times since first issued by the U.S. DOT in 1970.

What is compression?

Essentially, compression moves gas from Point A to Point B.   Mechanical equipment is used to maintain low pressures on a pipeline, allowing the wells to flow into that pipeline.  Compressors accomplish this by bringing in the gas at low pressures and pressurizing it to move it into the transmission pipeline.

What are the different types of compression?

There are three main types of compression utilized in the Barnett Shale.

•    Gas lift compression – a small horsepower compressor that compresses gas from
     a pipeline into a well bore to force out water that is blocking the gas flow of
     that well.

•    Wellhead compression – a small horsepower compressor on a well pad that
     compresses the gas from an individual well into a pipeline.

•    Centralized compression – large horsepower compressors that bring in gas from
     multiple wells on a gathering pipeline and compress it into a transmission pipeline.
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What is most commonly used within the city limits?

For the pipeline system, centralized compression is most common.  However, the production of nearly every gas well in the Barnett requires some amount of short term temporary gas lift compression to start the gas flow from the wellhead.

What is a compressor station?

A compressor station is where the gathered gas is prepared for sale to the transmission pipeline.  In these facilities the gas is dehydrated and compressed to a pressure high enough for delivery to the transmission pipeline.

What are pipeline companies doing to be sensitive of the area surrounding a compressor station?

Pipeline companies are evaluating the area where the compressor station is located and designing them to blend in with the surroundings.  In urban areas, acoustical buildings are utilized to enclose the compressors to reduce sound and landscaping is designed to enhance the facility.

How are compressor stations classified in federal regulations?

Location and design of the compressor facilities is regulated by the Code of Federal Regulations Title 49 Part 192.163.  Area Classification is regulated by CFR Title 49 Part 192.5.

Who regulates them?

The Railroad Commission of Texas and the U.S. DOT’s Pipeline and Hazardous Materials Safety Administration, with air quality permits by Texas Commission on Environmental Quality.Go to Top

Is a building permit required?

No, safety measures for compressors inside sound buildings are incorporated into the design of the compressor station as defined by the federal and state regulations.

What is the process in obtaining a pipeline easement?

A Right of Way agent will contact the property owner to discuss the need for the pipeline.  The property owner will be provided with the Texas Landowner’s Bill of Rights. A title search will be conducted to assure the easement is being acquired from the right individual(s) and that there has been no break in the chain of title for a substantial length of time.  A fair value for the easement is established for the property to be taken in the easement.  A survey of the easement area is conducted.  Easement is granted (signed) and payment exchanged.  In some cases the easement is signed before the survey plat is available.  In such cases the easement is held and filed of record upon receipt of the survey plat.

Is the Bill of Rights required or just a suggested notice?

The Landowner’s Bill of Rights is issued by the State of Texas Attorney General.  Any entity acquiring land for public use is required to provide a copy of the Landowner’s Bill of Rights to each property owner before negotiations occur.

Why does a pipeline company require a survey?

A survey of the property is the only way to establish accurate payment for the easement.  Additionally, a description of the easement is required for filing the instrument.Go to Top

What happens if the property owner will not grant survey permission?

If the property owner refuses to grant survey permission, the pipeline company may file an injunction to survey.  This will provide a temporary court order for the pipeline company to access the property for a survey only.  This order does not assign any easement or construction rights.

What happens if the property owner will not grant survey permission?

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Does the property owner receive compensation for a survey to be conducted?

No, a survey does not encumber the property in any way; no interest in the land is being acquired during survey.  Typically, surveyors only walk across the property, and there is no damage to the property.

Is the property owner paid if the pipeline company obtains the easement?

Yes, the Texas Property Code and the Texas Constitution require that a property owner receive just compensation for any property rights taken through the right of eminent domain or through agreeable negotiations.

How does a pipeline company get an easement if a private property owner will not agree to voluntarily grant the easement?

Through the process of condemnation, a pipeline company, recognized as a gas utility, may exercise the right of eminent domain to acquire the easement.

When an easement is obtained through condemnation, does the pipeline company typically get ownership of that land?

No. Texas law only allows a pipeline company to condemn for the rights that it needs to conduct its business, and that usually prevents a condemnation of the entire ownership (the “fee title”) to the land. Typically the pipeline company only gets an easement, which is a right to use the property but does not constitute ownership of the property.Go to Top

How does a pipeline company acquire the right of eminent domain?

Texas Utilities Code Section 181.004 specifies that a gas or electric corporation:
…has the right and power to enter on, condemn, and appropriate the land, right-of-way, easement, or other property of any person or corporation….

What is needed before a court will accept a pipeline company’s petition to condemn for an easement?

Texas Property Code Section 21.012 says what the condemnation petition must contain. It must state that the company and the landowner have been unable to agree on the landowner’s just compensation for the easement and that the company has given the landowner a Landowner’s Bill of Rights. It must also name the landowner, describe the property to be taken, and describe the use the company plans to make of the property. Before the petition is filed, the company must have determined that the pipeline facility is needed and where it should be located and must have tried to agree with the landowner on compensation for the taking.

How often will the pipeline company return to the pipeline easement?

Under the easement agreement the pipeline company retains the right to conduct inspections or maintenance on the pipeline at any time.  This means that the pipeline company may enter upon the easement without notifying the property owner.  Typically the pipeline company will conduct drive by inspections or physically walk the pipeline routes monthly.

Will the entire easement be cleared in order to construct this pipeline?

The condition of the easement will be considered on a case by case basis for each property owner.  Where the trench construction method is utilized the entire easement will be cleared and returned to grade after construction, as stipulated in the individual easement agreement.  Where HDD bore construction is utilized existing trees and vegetation are typically unharmed. 

Can I build over the permanent easement?

Permanent structures cannot be built over a pipeline easement.  Parking lots and driveway may be constructed along with other small scale landscaping improvements.

What is temporary workspace or easement?  Will the pipeline company be able to keep the temporary easement?

Additional workspace is needed during the construction of the pipeline.  This land will not be included in the permanent easement.  The terms of the temporary workspace are outlined in the easement agreement.  Once construction is completed the agreement to use the land for temporary workspace expires and is no longer valid.