Pipeline

Pipeline

Contents-

Introduction

Natural gas transmission system

Transmission Pipelines

Pipe-Coating Materials

Compressor Stations

Metering Stations

City Gate Stations

Valves

Pig Launching /Receiving Facilities

SCADA Centers

Access Roads

Process

Pipeline operation

Control strategy

U .S . natural gas pipeline network

List of pipelines used to transport natural gas in the United States

Gas Distribution and Pipeline System

Conclusions

References

Introduction-

Transportation of goods through a pipe is known as Pipeline Transport . Liquid and gases are sent most commonly

, but pneumatic tubes that transport solid capsules using compressed air have also been used . Large quantity of natural gas is transported across long distances through natural gas transmission lines . The analysis of these pipelines is very difficult and the day-to-day operations leave little time for optimization . Any chemically stable substance , gases and liquids can be sent through a pipeline . Therefore sewage , slurry water , or even beer pipelines exist , but arguably the most significant are those transporting oil and natural gas . Dmitri Mendeleev in 1863 firstly brought the idea . He suggested transporting of Petroleum through a pipe

The United States relies on natural gas for one-quarter of its energy needs . There are a lot of major natural gas production basins in United States and it has an extensive natural gas pipeline network , with almost 95 of U .S natural gas imports coming from Canada

At present , the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States . Gas flows from Canada to the United States through several major pipelines feeding U .S . markets in the Midwest , Northeast , Pacific Northwest , and California . Some of tr examples are the Alliance Pipeline , the Northern B Pipeline , the Maritimes Northeast Pipeline , the TransCanada Pipeline System , and West coast Energy pipelines . Of the natural gas consumed in the United States , 85 is produced domestically

The pipeline transmission system- the interstate highway ' for natural gas consists of 180 ,000 miles of high-strength steel pipe varying in diameter , normally between 30 and 36 inches in diameter . Huge amounts of natural gas is moved thousands of miles from producing regions to local natural gas utility delivery points with the help of transmission pipeline . These delivery points are known as city gate stations , are usually owned by distribution companies although some are owned by transmission companies . The pressure that is lost through friction as the gas moves through the steel pipes is increased at required distances by Compressor stations

Production , processing and purification , transmission and storage and distribution are the terms which describe the natural gas system . This essay focuses on the transmission pipeline

There are mainly two types of pipelines are present in USA-

Interstate - Pipeline systems that cross one or more States

Intrastate - Pipelines that operate only within State boundaries

U .S . Natural Gas Pipeline Network

Natural gas transmission system-

Natural gas is transported from the producer to the market areas via pipelines . The transmission segment of the gas industry is responsible for this . The transmission system is composed of pipelines , compressor stations , city gate stations and storage facilities

Transmission Pipelines-

Steel is used for making the transmission pipelines . They are generally operated at pressures ranging from 500 to 1 ,400 pounds per square inch gauge . Pipelines can measure anywhere from 6 to 48 inches in diameter , although certain component pipe sections can consist of small-diameter pipe that is as small as 0 .5 inch in diameter . However , usually only gathering and distribution systems use this small-diameter pipe , although some is used for control-line or gauge-line purposes . Mainline pipes or pipes in the principal pipeline in a given system are usually between 16 and 48 inches in diameter . Lateral pipelines , which deliver natural gas to or from the mainline are typically between 6 and 16 inches in diameter . Nearly all major interstate pipelines are between 24 and 36 inches in diameter . The actual pipeline is called line pipe ' and it consists of a strong carbon steel material engineered to meet standards set by the American Petroleum Institute (API American Society of Testing and Materials (ASTM , and American National Standards Institute (ANSI . Line pipe is produced in These steel mills are sometimes specialized to create only pipeline-quality components . There are two dissimilar production methods are used , one for small diameter pipes and one for large-diameter pipes . sheets of metal that are folded into a tube shape are utilized for large-diameter pipes , from 20 to 42 inches in diameter and the ends are welded or fused together to form a pipe section . On the other hand Small-diameter pipe can be produced seamlessly . Heating a metal bar to very high temperatures is involved in this technique and after the heating a hole is punched through the middle of the bar to produce a hollow tube . Before being shipped from the steel mill the pipe is tested to ensure that it can meet the pressure and strength standards for transporting natural gas . Pipelines are usually buried underground . The burial depth varies depending on the local geography along the pipeline route . 2 to 4 feet to top of pipe is Normal depth requirement . Many transmission pipeline companies transfer gas to metropolitan markets

A natural gas transmission pipeline in the western states has the average diameter of is around 20 inches with an average length of around 11 miles per segment between line valves . Approximately 68 ,000 miles of transmission pipelines are present in this region

Schematic of Natural Gas Production , Processing , Transmission and Storage

Pipe-Coating Materials-

The pipe should not be corroding once placed in the ground Hence coating mills apply pipe coatings on the pipes before grounding . The coating mill should be located adjacent to the pipe mill , so line pipe moves directly from the pipe manufacturer to the coating facility . To protect the pipe from moisture , corrosive soils , and construction-induced defects coating is necessary . A number of different coating techniques are present . Specialized coal tar enamel is used in the past for the coating purpose . Today , pipes are often protected with a fusion bond epoxy or extruded polyethylene . Both of which give the pipes a noticeable light yellow color . Cathodic protection is often used , which is a technique that involves inducing an electric current through the pipe to ward off corrosion

The external surface of the pipe is thoroughly cleaned with a shot-blast process before preparing for fusion-bond epoxy coating . After it the pipe is heated to a prescribed temperature and an epoxy powder is applied . The powder melts ' onto the heated pipe and forms a water-tight barrier The mill tests the coated pipe (called jeeping ) with high voltage to evaluate the coating 's insulating effectiveness prior to transporting the pipe to the job site

Typical Installation of a Large Transmission Natural Gas Pipe

Compressor Stations-

To accelerate the flow of gas Natural gas is highly pressurized as it travels through an interstate pipeline Compression of the natural gas occurs periodically along the pipe to ensure that the natural gas flowing through any one pipeline remains pressurized . Compressor stations are used to accomplish this . These Compressor stations are usually placed at 40 to 100 mile intervals along the pipeline . The natural gas is compressed at the compressor station by a turbine , motor or engine

Turbine compressors achieve their energy by using up a small amount of the natural gas that they compress . The turbine itself serves to operate a centrifugal compressor . The turbine contains a type of fan that compresses and pumps the natural gas through the pipeline . An electric motor is used at some compressor stations to turn the same type of centrifugal compressor . Any of the natural gas from the pipe is not required in this type of compression . However , it does need that a reliable source of electricity be located nearby Reciprocating natural gas engines are also used to power some compressor stations . These engines resemble very large automobile engines , and natural gas from the pipeline is used . Pistons get power by the combustion of the gas outside of the engine which serve to compress the natural gas . Some type of liquid separator are also used compressor stations for compressing natural gas , much like those used to dehydrate natural gas during its processing . Usually these separators consist of scrubbers and filters that capture any liquids or undesirable particles from the natural gas in the pipeline . Although natural gas in pipelines is considered a dry gas , it is not uncommon for a certain amount of water and hydrocarbons to condense out of the gas stream while in transit . The liquid separators , present at compressor stations ensure that the natural gas in the pipeline is as pure as possible , and usually filter the gas prior to compression . Compressor stations are powered by compressors that are each rated at several thousand horsepower (hp . The stations contain valves , pipes and control systems that monitor the functioning and operating parameters of the system . Most compressor stations are fully automated . The compressors are typically housed in a metal building with pipe appurtenances and other critical elements above ground . All electrical fittings within the metal building are explosion-proof

Natural Gas Compressor Station along an Interstate Pipeline

a metal building is used for the housing of the Reciprocating compressor along the pipeline . These stations are monitored or controlled by supervisory control and data acquisition (SCADA ) systems

The average size of an interstate compressor station in the western states is around 13 ,000 hp , with large variations in size found throughout the western region . 15 to 22 acres of land is needed for the Compressor station include an all-weather gravel access road , the compressor building cooling fans , a control building , and possibly two or three small auxiliary buildings . The compressor building as well as the piping and equipment are acoustically designed to keep noise to a minimum and are constructed using explosion-proof electrical fittings . Continuous Noise generates at a natural gas compressor station during operations

Natural gas piping , both aboveground and belowground associated with the installation of the interconnections metering stations , and pigging facilities at a compressor station are installed and pressure-tested using methods similar to those used for the main pipeline . After testing is successfully completed , the piping is tied into the main pipeline

Metering Stations Typical Metering Station City Gate Stations

The natural gas for a large number of distribution systems is received from transmission pipelines and fed through one or more city gate stations , sometimes called town b or tap stations . to meter the gas and reduce its pressure these stations are used . The latter operates at a much lower pressure (reduced from approximately 500-1 ,400 psig to about 0 .25-300 psig . Figure shows a city gate station . To protect it from the weather it should be covered with a fiberglass enclosure or metal building . Metering devices are used by the most city gate stations to measure the gas flow . Pressure of the natural gas is reduced with the help of pressure regulators . These devices control the rate of gas flow and /or pressure through the station and maintain the desired pressure or flow level in the distribution system

City Gate Gas Measurement and Regulation Station

Valves-

A great number of valves along their entire length are present in Interstate pipelines . We can also call these valves gateways because they work like a gateway . They are usually open and permit natural gas to flow freely , but they can be used to stop gas flow along a certain section of pipe

Aboveground Valve on Natural Gas Pipeline

Pig Launching /Receiving Facilities-

Pigging facilities consist of pig launching or receiving equipment and allow the pipeline to accommodate a high-resolution internal inspection tool . Pigs are devices that are placed into a pipeline to execute definite functions . Some are used to clean the inside of the pipeline or to monitor its internal and external condition . Launchers and receivers are facilities that enable pigs to be placed into or removed from the pipeline

A pigging facility is usually smaller than a typical compressor station site , but is typically twice the size of a valve site

Crew Inserting a Pig into a Pipeline

SCADA Centers

Customers are present on the both ends of the pipeline . The producers and processors that enter gas into the pipeline and the consumers and local distribution companies those obtain gas out of the pipeline . Sophisticated control systems are required to control the natural gas that enters the pipeline and ensure that all customers obtain timely delivery of their section of this gas and to watch the gas as it travels through all sections of a potentially very lengthy pipeline network . To complete the task of monitoring and controlling the natural gas that is traveling through the pipeline supervisory control and data acquisition (SCADA ) systems are used . Centralized gas control stations assemble , assimilate , and manage the data received from monitoring city gate stations and compressor stations all along the pipeline

Mainly of the data that is received by a control station is provided by supervisory control and data acquisition (SCADA systems . These systems are basically sophisticated communications systems that take measurements and gather data along the pipeline (generally in metering or compressor stations and valves ) and transmit the data to the centralized control station . Flow rate throughout the pipeline , operational status pressure , and temperature readings may all be used to assess the status of the pipeline at any one time

This information permits pipeline engineers to identify accurately what is happening along the pipeline at all times which permits fast reactions to equipment malfunctions , leaks or any other unusual activity along the pipeline , as well as to monitoring load control

SCADA Center

Access Roads

Pipeline companies normally try to use existing roads to give access to the construction ROW . The access roads are used on a temporary basis to transport personnel , equipment , vehicles heavy trucks , and materials to project work areas . Some of these roads may not support heavy construction equipment and therefore , would be used only for light truck traffic (e .g pickup trucks

Typical Construction ROW

Process -

A part of the pipeline which is approximately 250 miles in length transports gas to a number of states of the northeastern U .S . six compressor stations along this particular segment are present there . Most of the gas enters the pipeline at the first station with the balance entering at the fifth station . Gas is delivered at numerous points along the pipeline and the remainder flows out into the next part of the pipeline . Either the suction pressure , the flow , or the discharge pressure is controlled locally at each of these stations . Fig . shows a schematic of the pipeline segment . The first station consists of six reciprocating compressors . Two of these compressors are equipped with air /fuel ratio control and digital speed control . This station is usually on flow control to meet contractual obligations . Three gas-turbine-driven centrifugal compressors are present at the second station and suction pressure is controlled at this station . Suction pressure is controlled by maintaining turbine speed . Three gas-driven reciprocating compressors are had by the third station . This station is normally on suction control and individual engine controls are very similar to the first station . The fourth station also employs three gas-turbine-driven centrifugal compressors . Control at this station is very similar to the second station . The fifth station consists of six reciprocating compressors and much of the delivery along the line occurs at this station . The sixth station employs two turbine-driven centrifugal compressors and normally is run for peak deliveries only . It normally is set on suction control at the time of operation . Currently an online supervisory control and data acquisition (SCADA ) system is used to control the whole system centrally by using the dispatchers . Each day , the dispatchers receive a preview of the day 's nominations so they can prepare a plan of system parameters . The dispatchers are required to meet contract flow rates and pressures at all of the supply and delivery points along the pipeline

Schematic of the pipeline

Pipeline operation-

A lot of natural gas pipelines in the U .S . drive in an extremely dynamic fashion . The flows into and out of the system vary during the day . This trend is expected to enhance with the deregulation of the gas industry . This frequently raises the question as to whether there is a single group of set points that will result in optimal operation for an entire day . Since the introduction of optimizers , the debate of steady-state versus dynamic optimization has raged . It is the view of the authors that steady-state optimization coupled with dynamic online control gives a practical solution to problems in systems which approach steady state most of the time . It is envisioned that considerable changes in the pipeline operations happen once a day . At some time new flow enters the pipeline during the day . This flow may be maintained until the next day . The optimizer has to be run to decide the new operating conditions when these changes are expected . It may be a good idea to run the optimizer at a higher frequency if the change in flow occurs at a greater frequency . Optimizers by themselves are not sufficient for the dispatcher to run the pipeline in an optimal fashion . The optimization is made automatic by a control scheme , so that the dispatcher can use the control scheme to shift the pipeline from one optimal state to another

Control strategy-

Most compressor stations consist of local station controllers which are able to control the suction pressure , the discharge pressure or the flow or some combination of the three However , control is localized and the interaction is not taken into account , between compressor stations . In general , during a variation in the flow through the pipeline the controllers interact to a very large extent and can often oppose each other . Model-predictive controllers account for interactions between different control actions and all the control actions are computed to reach a general aim . These controllers also forecast the effect of control action into the future . Hence they can act faster and more efficiently than feedback controllers . Technically , the control scheme has the following three objectives

1 ) Keep the pipeline at a most favorable pressure pro (normal mode

2 ) Gracefully handle the daily change in nominations (transition mode ) with proper unit selection

3 ) Automatically handle operations in the event of a compressor going down (event mode

In meeting these control objectives , the overall project objectives are met . The controller maintains the pipeline at a best pressure pro recommended by the optimizer and confirmed by the dispatcher . Pressure pros at which the compressors are most efficient is chosen by the optimizer . Energy losses can be minimized by this and hence fuel usage . A scheduling algorithm prepares the pipeline for a change in nominations for the day during the transition mode of operation . The dispatcher with the necessary information to move to the new flow is provided by a heuristic-based scheduling algorithm . On the dispatcher 's approval , this algorithm is used to shift the pipeline to its new set of best possible operating conditions Units may come up or go down on definite dispatcher commands or depending on some logic in the local control algorithm . The overall control scheme has to be capable to handle both cases . In the case of local controllers bringing up or shutting down units automatically , the plant control engineers need to be involved in matching the unit selection logic of the local controllers with the logic of the optimizer . An event mode is reached if a compressor goes down creating a shortage of horsepower at a particular station . The downstream stations speed up to account for this shortage . The proposed control scheme is operated by the dispatcher from the central control room . The controllers are in touch with the SCADA and sit on top ' of the local station controllers . The control scheme gives set points to the local controllers that would then move the system toward optimality . To obtain the optimal pressure pros and unit selection , the control scheme also communicates with the optimizer . In different industries like ammonia , sulfur recovery plants , and gas plants , the multivariable robust model-predictive control strategy is fairly common

Schematic of the control system

U .S . natural gas pipeline network-

The U .S . natural gas pipeline network is a extremely integrated transmission and distribution grid that can transport natural gas to and from nearly any location in the lower 48 States The natural gas pipeline grid comprises

More than 210 natural gas pipeline systems

302 ,000 miles of interstate and intrastate transmission pipelines

More than 1 ,400 compressor stations that maintain pressure on the natural gas pipeline network and assure continuous forward movement of supplies

More than 11 ,000 delivery points , 5 ,000 receipt points , and 1 ,400 interconnection points that provide for the transfer of natural gas throughout the United States

29 hubs or market centers that provide additional interconnections

399 underground natural gas storage facilities

49 locations where natural gas can be imported /exported via pipelines

7 LNG (liquefied natural gas ) import facilities and 100 LNG peaking facilities

Interstate - Pipeline systems that cross one or more States

Intrastate - Pipelines that operate only within State boundaries

List of pipelines used to transport natural gas in the United States-

This is a list of pipelines used to transport natural gas in the United States . The interstate pipelines are regulated by the Federal Energy Regulatory Commission (FERC ) in the US Intrastate pipelines are regulated by state , provincial or local jurisdictions

United States interstate pipelines-

FERC requires most interstate pipelines to maintain an interactive web site with standardized information regarding their operations under a heading of "Informational Postings The exact legal name of each company appears below . Many of these companies are wholly owned subsidiaries of larger publicly-traded companies

Major interstate pipelines-

Alliance Pipeline L .P

ANR Pipeline Company - formerly Michican Wisconsin

CenterPoint Energy Gas Transmission Company

Centerpoint Energy - Mississippi River - formerly , Mississippi River Transmission

Colorado Interstate Gas Company

Columbia Gas Transmission Corporation

Columbia Gulf Transmission Company

Dominion Transmission , Inc . - formerly Consolidated Gas Transmission

East Tennessee Natural Gas Company

El Paso Natural Gas Company

Florida Gas Transmission Company

Gas Transmission Northwest Corporation - formerly Pacific Gas Transmission

Great Lakes Gas Transmission Limited Partnership

Gulf South Pipeline Company L

- formerly , United Gas Pipeline Company

Kinder Morgan Interstate Gas Transmission LLC - owned by Kinder Morgan Energy Partners , formerly Kansas Nebraska and KN Energy

Kern River Gas Transmission Company

Maritimes Northeast Pipeline , L .L .C

Midwestern Gas Transmission Company

National Fuel Gas Supply Corporation

Natural Gas Pipeline Company Of America

Northern B Pipeline Company

Northern Natural Gas Company

Northwest Pipeline Corporation

Panhandle Eastern Pipe Line Company , LP

Questar Pipeline Company

Questar Southern Trails Pipeline Company

Southern Natural Gas Company

Southern Star Central Gas Pipeline , Inc

Tennessee Gas Pipeline Company

Texas Eastern Transmission , L

p Texas Gas Pipe Line Corporation

Texas Gas Transmission , LLC

Texas-Ohio Pipeline , Inc

Trailblazer Pipeline Company

Transcontinental Gas Pipe Line Corporation

Transwestern Pipeline Company , LLC

Trunkline Gas Company , LLC

Viking Gas Transmission Company

Williston Basin Interstate Pipeline Co

Minor interstate pipelines

ANR Storage Company

Arkansas Western Pipeline , L . L . C

Black Marlin Pipeline Company

Blue Dolphin Pipe Line Company

Blue Lake Gas Storage Company

Boundary Gas , Incorporated

B-R Pipeline Company

Canyon Creek Compression Company

Caprock Pipeline Company

Central Kentucky Transmission Company

Central New York Oil And Gas Company , LLC

Chandeleur Pipe Line Company

Cheyenne Plains Gas Pipeline Company , L .L .C

Cotton Valley Compression LLC

Clear Creek Storage Company , LLC

Crossroads Pipeline Company

Discovery Gas Transmission LLC

Dauphin Island Gathering Partners

Destin Pipeline Company , L .L .C

Distrigas Corporation

Dominion South Pipeline Co , LP

Eastern Shore Natural Gas Company

Egan Hub Storage , LLC

Enbridge Pipelines (Alatenn ) L .L .C (formerly , Alabama-Tennessee

Enbridge Pipelines (Midla ) L .L .C (formerly , Mid-Louisiana

Enbridge Pipelines (Kpc

Equitrans , L .

p Energy West Development , Inc

Freebird Gas Storage , L .L .C

Garden Banks Gas Pipeline , LLC

Gas Gathering Corporation

Gasdel Pipeline System , Inc

Gulf States Transmission Corporation

Great Lakes Gas Transport , L .L .C

Guardian Pipeline , L .L .C

Granite State Gas Transmission , Inc

Honeoye Storage Corporation

Horizon Pipeline Company , L .L .C

Iroquois Gas Transmission System , L .P

The Inland Gas Company

Centra Pipelines Minnesota Inc

Jupiter Energy Corporation

KO Transmission Company

Kentucky West Virginia Gas Company

Louisiana-Nevada Transit Company

Markwest New Mexico L .P (Pinnacle

Millennium Pipeline Company , L .P

MIGC , Inc

Michigan Consolidated Gas Company

Michigan Gas Storage Company

Midwest Gas Storage , Inc

Mississippi Canyon Gas Pipeline , LLC

Missouri Interstate Gas , LLC

Mobile Bay Pipeline Company

Mojave Pipeline Company

Ngo Transmission , Inc

Nora Transmission Company

Norteso Pipeline Company

North Baja Pipeline , LLC

North Penn Gas Company

Oktex Pipeline Company

Overthrust Pipeline Company

Ozark Gas Transmission , L .L .C

Penn-York Energy Corporation

Gas Transmission Northwest Corp

Pacific Interstate Transmission Company

Paiute Pipeline Company

Petal Gas Storage , L . L . C

Pine Needle LNG Company , LLC (peak shaving storage - not an import terminal

Portland Natural Gas Transmission System

Puget Sound Energy , Inc

Richfield Gas Storage System

Riverside Pipeline Company , L .

p Rockies Express Pipeline LLC (Entrega

Sabine Pipe Line Company LLC

Saltville Gas Storage Company L .L .C

SCG Pipeline Inc . - merger pending with South Carolina Pipeline Corp

Sea Robin Pipeline Company , LLC

Southwest Gas Storage Company

Steuben Gas Storage Company

T C

Gathering Co .Tuscarora Gas Transmission Company

Trans-Union Interstate Pipeline , L .P

TransColorado Gas Transmission Company

Vector Pipeline L .P

Venice Gathering System , L . L . C

Washington Natural Gas Company

West Texas Gas , Inc

Western Gas Interstate Company

Western Transmission Corporation

Westgas Interstate , Inc

Young Gas Storage Company , Ltd

Wyoming Interstate Company , Ltd

Portland General Electric Company

Nornew Energy Supply , Inc

Phillips Gas Pipeline Company

U S G Pipeline Company

Predominantly Offshore Pipelines

Black Marlin Pipeline Co

Chandeleur Pipeline Co

Destin Pipeline Co , LLC

Dauphin Island Gathering Partners

Discovery Gas Transmission LLC

Enbridge Pipelines (UTOS ) LLC

Garden Banks Gas Pipeline , LLC

Gulfstream Natural Gas System , L .L .C

High Island Offshore System , LLC [6]

Mississippi Gas Canyon Pipeline , LLC

Nautilus Pipeline Co , LLC

Panther Interstate Pipeline Energy , LLC

Pacific Interstate Offshore Company

Pacific Offshore Pipeline Company

Sea Robin Pipeline Co

Shell Offshore , Inc

Stingray Pipeline Co , LLC

Venice Gathering System , LLC

LNG Importation /Export Terminals-

Current US LNG Terminals

Distrigas Of Massachusetts LLC

Dominion Cove Point LNG , LP

Gulf Gateway Deepwater Port[7]

Keyspan LNG , LP (Alng

Phillips Alaska Natural Gas Corporation and Marathon Oil Company

Southern LNG Inc

Trunkline LNG Company , LLC

Hinshaw Pipelines-

Although these pipelines flow gas in interstate commerce , they are subject to state regulation

Atlanta Gas Light Company

Cobra Pipeline Company , Ltd

East Ohio Gas Company

Empire State Pipeline

Michigan Consolidated Gas Company

Nornew Energy Supply , Inc

Northern Illinois Gas Company (Nicor Gas

Pacific Gas and Electric Company

Gas Distribution and Pipeline System

Gas Distribution

Nicor Gas Service Territory

Major Gas Main

Underground Storage Field

Major Cities

Interstate Pipeline Transporters

Natural Gas Pipeline Company of America

Northern Natural Gas Company

Midwestern Gas Transmission Company

Panhandle Eastern Pipe Line Company

ANR Pipeline

Alliance Pipeline

Northern B

Horizon

Conclusions-

The control system , along with a commercial pipeline optimizer controls and optimizes a pipeline segment . The strategy is aimed at minimizing fuel consumption of the compressors , easing the scheduling of changes in gas flow rates , proper unit selection and handling equipment outages . Commercial optimizers that let the dispatcher run the software are very advantageous because the dispatcher can make decisions based on the optimization results as opposed to individual preferences . The control scheme automates the optimization operation , which keeps the dispatcher free to perform other duties . The advantages of the control scheme should be very apparent in a complicated network , where it is very difficult to predict the effect of changing one station speed on the rest of the system Knowledge-based scheduling algorithms help considerably in moving the pipeline from one steady state to another

References-

AGA (American Gas Association , Natural Gas 101 - An Introduction to the Natural Gas Industry , April 24 , 2008 HYPERLINK "http /www .aga .org /Template .cfm ?Section Presentations7 template /Conten tManagement /ContentDisplay .cfm ContentID 14896 http /www .aga .org /Template .cfm ?Section Presentations7 template /Content Management /ContentDisplay .cfm ContentID 14896

Deborah russ , Open Season Pathfinder Gas Pipeline Project April 24 , 2008 , HYPERLINK "http /www .transcanada .com /pdf /company /projects /pathfinder_open_season pdf www .transcanada .com /pdf /company /projects /pathfinder_open_season .pdf

CEC (California Energy Commission , Chapter 9 : Natural Gas Distribution System , April 24 , 2008 , HYPERLINK "http /www .energyquest .ca .gov /story /chapter09 .html http /www .energyquest .ca .gov /story /chapter09 .html

FERC (Federal Energy Regulatory Commission , Chapter 2 Proposed Action , April 24 , 2008 , HYPERLINK "http /www .ferc .gov /industries /gas /enviro /eis /2005 /08-12-05 .asp http /www .ferc .gov /industries /gas /enviro /eis /2005 /08-12-05 .asp

Natural Gas Pipeline Network : Changing and Growing , June 01 ,1999 , April 24 , 2008 , HYPERLINK "http /www .eia .doe .gov /pub /oil_gas /natural_gas /analysis_publications /na tural_gas_1998_issues_trends /pdf /chapter5 .pdf www .eia .doe .gov /pub /oil_gas /natural_gas /analysis_publications /natural_ga s_1998_issues_trends /pdf /chapter5 .pdf

Comprehensive Inspection Form - Gas Distribution Pipeline August 03 ,2006 , April 24 , 2008 , HYPERLINK "http /dnr .louisiana .gov /cons /CONSERPI /documents /gasdist /ComprehensiveI nspectionForm .pdf http /dnr .louisiana .gov /cons /CONSERPI /documents /gasdist /ComprehensiveIn spectionForm .pdf

Gas Pipelines , April 24 , 2008 , HYPERLINK "http /www .shell .com /static /shellgasandpower-en /downloads /our_brochures /gaspipelines .pdf www .shell .com /static /shellgasandpower-en /downloads /our_brochures /gaspipe lines .pdf

Pipeline transportation and underground storage , April 24 2008 , HYPERLINK "http /www .eia .doe .gov /pub /oil_gas /natural_gas /feature_articles /2006 /ng pipeline /ngpipeline .pdf www .eia .doe .gov /pub /oil_gas /natural_gas /feature_articles /2006 /ngpipeline /ngpipeline .pdf

LAA , The Alaska Natural Gas Pipeline Project , April 24 2008 , HYPERLINK "http /lba .legis .state .ak .us /pubs /angpp_clean .ppt http /lba .legis .state .ak .us /pubs /angpp_clean .ppt

W . A . Poe , U . Basu , G . Venkataramanan , and E .

. Ferber Gas pipeline optimization and control ' Int . J . Hydraulic Eng

R . Lin , H . Munsif , and W . A . Poe , Primary reformer operation : A unique application of multivariable control Nitrogen , vol . 230 , pp . 35-41 , 1997

P . N . Berkowitz , M . Papadopoulus , and W . A . Poe Multivariable control / optimization for sulfur plants ' in Proc . Laurence Reid Gas Conditioning Conf , 1997 , pp . 42-70

M . C . Alexander , O . Martin , U . Basu , and W . A . Poe Multivariable control of Texaco 's Eunice South gas plant ' in Proc . 77th Annu . Conv . Gas Processors Assoc , 1998 , pp . 63-68

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