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[[Image:Pipeline-Diagram.jpg|thumb|500px|Pipeline Schematic]]
[[Image:Pipeline-Diagram.jpg|thumb|500px|Pipeline Schematic]]


Field devices include instrumentation, gathering units and communication systems. The field instrumentation includes flow, pressure and temperature gauges/transmitters, and other [[Instrumentation]] to measure the relevant data required to operate, which are installed along the pipeline on some specific locations, such as injection or delivery stations, pump stations (liquid pipelines) or compressor stations (gas pipelines), and block valve stations.
Field devices include basically instrumentation, gathering units and communication systems. The field [[Instrumentation]] is related to flow, pressure and temperature gauges/transmitters, as well as other devices to measure the relevant data required to operate. These field instruments are installed along the pipeline on some specific locations, such as injection or delivery stations, pump stations (liquid pipelines) or compressor stations (gas pipelines), and block valve stations.


The information measured by these field instruments is then gathered in local [[Remote Terminal Unit]]s (RTU) that transfer the field data to a central location in real time using communication systems, such as satellite channels, micro wave links or cellular phone connections.
The information measured by these field instruments is then gathered in local [[Remote Terminal Unit]]s (RTU) that transfer the field data to a central location in real time using communication systems, such as satellite channels, micro wave links or cellular phone connections.

Revision as of 22:46, 7 November 2007

An elevated section of the Alaska Pipeline.

Pipeline transport is a transportation of goods through a pipe. Most commonly, liquid and gases are sent, but pneumatic tubes that transport solid capsules using compressed air have also been used.

As for gases and liquids, any chemically stable substance can be sent through a pipeline. Therefore sewage, slurry, water, or even beer pipelines exist; but arguably the most important are those transporting oil and natural gas. Often these pipelines are inspected and cleaned using pipeline inspection gauges ("pigs"). Pipeline cleaners are also known as "Go-devils" [1]

Oil and natural gas pipelines

A Pig launcher/receiver, belonging to the natural gas pipeline in Switzerland.

There is some argument as to when the first real oil pipeline was constructed. Some say pipeline transport was pioneered by Vladimir Shukhov and the Branobel company in the late 19th century. Others say oil pipelines originated when the Oil Transport Association first constructed a 2-inch wrought iron pipeline over a 6-mile track from an oil field to Pennsylvania to a rail road station in Oil Creek, in the 1860s. No matter, piplines are generally the most economical way to transport large quantities of oil or natural gas over land. Compared to railroad, they have lower cost per unit and also higher capacity. Although pipelines can be built even under the sea, that process is both economically and technically very demanding, so the majority of oil at sea is transported by tanker ships.

Oil pipelines are made from steel or plastic tubes with inner diameter from 30 to 120 cm (about 12 to 47 inches). Where possible, they are built above the surface. However, in more developed, urban, environmentally sensitive or potentially dangerous areas they are buried underground at a typical depth of about 1.3 - 1.6 metres (about 3 feet). The oil is kept in motion by a system of pump stations built along the pipeline and usually flows at speed of about 1 to 6 m/s. Multi-product pipelines are used to transport two or more different products in sequence in the same pipeline. Usually in multi-product pipelines there is no physical separation between the different products. Some mixing of adjacent products occurs, producing interface. This interface is removed from the pipeline at receiving facilities and segregated to prevent contamination.

Crude oil contains varying amounts of wax, or paraffin, and in colder climates wax buildup may occur within a pipeline. To clear wax deposition, mechanical pigs may be sent along the line periodically.

For natural gas, smaller feeder lines are used to distribute the fuel to homes and businesses downstream of larger transportation pipelines, similarly constructed of carbon steel and varying in size from 12 inches in diameter to 48 inches in diameter. The gas is pressurized by compressor stations spaced approximately every 70–100 miles and is odorless unless mixed with a mercaptan odorant where identified by the proper regulating body.

In the U.S. pipelines are regulated by the Pipeline and Hazardous Materials Safety Administration (PHMSA); offshore pipelines are regulated by the Minerals Management Service (MMS). In Canada pipelines are regulated by either the provincial regulators or, if they cross provincial boundaries or the Canada/US border, by the National Energy Board (NEB). Government regulations in Canada and the United States require that buried fuel pipelines must be protected from corrosion. Often, the most economical method of corrosion control is by use of pipeline coating in conjunction with cathodic protection and technology to monitor the pipeline. Above ground, cathodic protection is not an option; the coating is the only external protection.

Pipeline Operation

When a pipeline is built, the construction project does not only cover the civil work to lay down or bury the pipeline and build the pump/compressor stations, but also all the work related to the installation of the field devices that will support the remote operation of these networks.

File:Pipeline-Diagram.jpg
Pipeline Schematic

Field devices include basically instrumentation, gathering units and communication systems. The field Instrumentation is related to flow, pressure and temperature gauges/transmitters, as well as other devices to measure the relevant data required to operate. These field instruments are installed along the pipeline on some specific locations, such as injection or delivery stations, pump stations (liquid pipelines) or compressor stations (gas pipelines), and block valve stations.

The information measured by these field instruments is then gathered in local Remote Terminal Units (RTU) that transfer the field data to a central location in real time using communication systems, such as satellite channels, micro wave links or cellular phone connections.

Pipelines are then controlled and operated remotely, from what is usually known as The Main Control Room. In this specific center, all the data related to field measurement is consolidated in one central database. The data is received from the multiple RTUs installed along the pipeline. It is common to find RTUs installed every 20 miles or so, even though it is not a design rule, it is a very usual practice in liquid pipelines. Overall the location of these devices depends exclusively on the nature of the product being transported, the trayectory of the pipeline and/or the operational conditions of the line.

SCADA System for Pipelines

The SCADA system at the Main Control Room, then receives all the field data and presents it to the pipeline operator through a set of screens or SCADA#Human_Machine_Interface, showing the main operational conditions of the pipeline. The operator can monitor the hydraulic conditions of the line, as well as remotely manipulate pumps, compressors, valves, deliveries, etc. sending operational commands (open/close valves, turn on/off compressors or pumps, change setpoints, etc.) through the SCADA system to the field.

To optimize and secure the operation of these assets, some pipeline companies are using what is called Advanced Pipeline Applications, which are software tools installed on top of the SCADA system, that provide extended functionality to perform leak detection, leak location, batch tracking (liquid lines), pig tracking, composition tracking, predictive modeling, look ahead modeling, operator training and more.

Leak Detection Systems

Since oil and gas pipelines represent one of the most important assets for the current economic and social development of almost any country, it has been required either by government regulations or internal policies to ensure the safety of the assets as well as of the population and the environment where these pipelines run across.

Pipeline companies face different operational challenges depending on three main factors; government regulation, environmental constrains and social situations. Agencies such as the Pipeline and Hazardous Materials Safety Administration from the Department of Transportation (DOT) in US, regulates the operation of pipelines all over the country; similar agencies or Ministers play the same role in different countries, establishing all the norms and restrictions to operate these networks. Pipeline companies should comply with these regulations which may define from basics such as minimum staff to run the operation, operator training requirements, up to very specifics including pipeline facilities, technology and applications required to ensure operational safety of the lines. As an example of these regulations, in the State of Washington, it is mandatory for all pipeline operators to be able to detect and locate leaks of 8 percent of maximum flow within 15 minutes or less.

The social situation also affects directly the operation of pipelines. In third world countries, product theft is a critical problem for pipeline companies. It is very often to find unauthorized extractions in the middle of the pipeline, then it is required to have the technology to detect and locate these controlled leaks. In this case, the detection levels should be under 2 percent of maximum flow, with a high expectation for location accuracy.

Different types of technologies and strategies have been implemented, from walking the lines every so often up to satellite surveillance. However the most common technology to protect these lines from occasional leaks is know as Computational Pipeline Monitoring Systems or CPM. CPM takes information from the field related to pressures, flows and temperatures to estimate the hydraulic behavior of the product being transported. Once the estimation is done, the results are compared to other field references to detect the presence of an anomaly or unexpected situation, which may be related to a leak incident. These CPM systems are the foundation to ensure the operational security of these pipelines.

The American Petroleum Institute has published several articles during the last 20 years related to the considerations to implement and evaluate the performance of a CPM in liquids pipelines, the API Publications are:

- API 1130 – Computational pipeline monitoring for liquids pipelines

- API 1155 – Evaluation methodology for software based leak detection systems

- API 1149 – Pipeline variable uncertainties & their effects on leak detectability

Accidents

Pipelines conveying flammable or explosive material such as natural gas or oil pose special safety concerns.

For a more complete list see Pipeline accidents
  • June 4, 1989 - sparks from two passing trains detonated gas leaking from an LPG pipeline near Ufa, Russia. Up to 645 people were reported killed.
  • October 17, 1998 - at Jesse in the Niger Delta in Nigeria, a petroleum pipeline exploded killing about 1,200 villagers, some of whom were scavenging gasoline - the worst of several similar incidents in this country.
  • June 10, 1999 - a pipeline rupture in a Bellingham, Washington park led to the release of 277,200 gallons of gasoline. The gasoline was ignited, causing an explosion that killed two children and one adult.
  • August 19, 2000 - natural gas pipeline rupture and fire near Carlsbad, New Mexico this explosion and fire killed 12 members of the same family. The cause was due to severe internal corrosion of the pipeline.
  • July 30, 2004 - a major natural gas pipeline exploded in Ghislenghien, Belgium near Ath (thirty kilometres southwest of Brussels), killing at least 23 people and leaving 122 wounded, some critically. (CNN) (Expatica)
  • May 12, 2006 - an oil pipeline ruptured outside Lagos, Nigeria. Up to 200 people may have been killed. See Nigeria oil blast.
  • November 1, 2007 - a propane pipeline exploded near Carmichael, Mississippi, about 30 miles south of Meridian, Mississippi. Two people were killed instantly and an additional four were injured. Several homes were destroyed and sixty families were displaced. The pipeline is owned by Enterprise Products Partners LP, and runs from Mont Belvieu, Texas, to Apex, North Carolina, according to an Enterprise spokesman. [2]]

Some oil/gas pipelines

Map of pipelines in Europe: [3]

Some oil/gas pipeline companies

Biobutanol

  • Biobutanol can be transported using existing pipelines.

Pipelines for other liquids

Water pipelines

The Los Angeles Aqueduct in Antelope Valley.
Main article: Aqueduct

Two millennia ago the ancient Romans made use of large aqueducts to transport water from higher altitudes by building the aqueducts in graduated segments that allowed gravity to simply push the rushing water along until it reached its intended destination. Hundreds of these were built throughout Europe and elsewhere, and along with flour mills were considered the lifeline of the Roman Empire. The ancient Chinese also made use of channels and pipe systems for public works. The infamous Han Dynasty court eunuch Zhang Rang (d. 189 AD) once ordered the engineer Bi Lan to construct a series of square-pallet chain pumps outside the capital city of Luoyang.[1] These chain pumps serviced the imperial palaces and living quarters of the capital city as the water lifted by the chain pumps were brought in by a stoneware pipe system.[1][2]

Pipelines are useful for transporting water for drinking or irrigation over long distances when it needs to move over hills, or where canals or channels are poor choices due to considerations of evaporation, pollution, or environmental impact.

The 530km(360 mile) Goldfields Water Supply Scheme in Western Australia using 760mm(30inch) and completed in 1903 was the largest water supply scheme of its time.[3][4]

Example significant water pipelines in South Australia are the Morgan-Whyalla (completed 1944) and Mannum-Adelaide [4] (completed 1955) pipelines.

There are two Los Angeles, California aqueducts, the First Los Angeles Aqueduct (completed 1913) and the Second Los Angeles Aqueduct (completed 1970) which also include extensive use of pipelines.

Beverage pipelines

Brine pipelines

The town of Hallstatt in Austria claims to contain "the oldest industrial pipeline in the world", dating back to 1595.[5] It was constructed from 13,000 trunks to transport the saline solution for 40 kilometers from Hallstatt to Ebensee.[6]

Beer pipelines

Bars in the Veltins-Arena, a major football ground in Gelsenkirchen, Germany, are interconnected by a 5 km long beer pipeline. It is the favourite method for distributing beer in such large stadiums, because the bars have to overcome big differences between demands during various stages of a match; this allows them to be supplied by a central tank.

Pipelines as targets

Pipelines can be the target of vandalism, sabotage, or even terrorist attacks. In war, pipelines are often the target of military attacks, as destruction of pipelines can seriously disrupt enemy logistics. Leaky tubes can cause mass floods in places that have been affected around the globe that are short of water. Such as the Tehran incident

See also

Wikimedia Commons has media related to Pipeline transport.

References

  1. ^ a b Needham, Joseph (1986). Science and Civilization in China: Volume 4, Part 2. Taipei: Caves Books Ltd. Page 33.
  2. ^ Needham, Volume 4, Part 2, 345-346.
  3. ^ Mephan Ferguson Australian Dictionary of Biography(online version)
  4. ^ The Forrest family Dynasties, ABC. Retrieved 17 September 2006.
  5. ^ Billie Ann Lopez. "Hallstatt's White Gold - Salt". Retrieved 2007-05-15. {{cite web}}: Cite has empty unknown parameters: |month= and |coauthors= (help)
  6. ^ See the article Hallstatt for details and references.

Oil and Gas Pipelines in NonTechnical Language, T. Miesner and W. Leffler, PennWell Corporation, 2006. Purchase from this link

[5]

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