• How Pipelines Work
  • Corrosion Prevention
  • Pigs and Smart Pigs
  • Central Coordination and Control
  • Training
    
    
• Myths and Misleading Statements About Oil and Natural Gas Pipelines
  • Oil pipeline companies are doing everything they can to prevent leaks because lost raw materials and products cost companies money.
  • Pipelines are highly regulated.
  • The most common cause of pipeline spills is third party damage.
  • Pipelines are likely targets of terrorism, so information about pipelines should be kept off the Internet and away from the general public.
  • Given the amount of oil transported, pipelines spill only a negligible amount.
  • Pipelines are the safest way to transport petroleum.

   

How Pipelines Work

The nation's oil pipelines transport crude oil from oilfields to refineries where the oil is turned into dozens of useful products such as gasoline, home heating oil, jet fuel, diesel, lubricants and the raw materials for fertilizer, chemicals and pharmaceuticals. They then transport refined products to depots that distribute them to the companies and consumers that daily rely on a steady and cheaply transported supply of these products.

MAJOR CRUDE OIL PIPELINES

Pipeline pathways first transport crude oil from oil fields and coastal shipping terminals to refineries. Then, after the oil is processed, pipelines handle the second part of the journey - transporting gasoline, jet fuel, heating oil, diesel and other refined products to distribution centers.

Many different kinds of oil and oil products are shipped through pipelines in batches. The physical principles of hydraulics keep the batches of liquid from blending and contaminating one another except where they actually touch. These "interfaces" between different shipments are separated out when they arrive at their destination and are reprocessed.

Sometimes batches are separated by metal "pigs" or plugs that keep batches from touching. Pigs are also used for cleaning the interior surfaces of pipelines to help prevent corrosion. Specially developed "smart" pigs, containing instrumentation packages, are used to double check pipeline integrity.

SEQUENCE CHART: HOW PETROLEUM FLOWS IN A PIPELINE

The first oil pipeline in the United States was built in 1865, following the discovery of oil in Pennsylvania. By the early 1900s, major discoveries had been made in Texas, Oklahoma and Kansas and pipelines had become a common method of moving crude oil. However, these early pipelines have long since been decommissioned. They were small diameter pipes that were quite inefficient by today's standards.

Leading up to World War II, pipeline companies were operating a maze of these small-diameter pipes laid out in parallel in order to carry enough capacity to fulfill the nation's needs for petroleum. Pump stations were powered by diesel engines, and were usually spaced every 30 miles. Each of these pump stations had to be manned around the clock to keep the system operating properly and the coordination of these multiple operating stations meant there was a lot more opportunity for human error.

Following the war, a technological revolution took place. The need for technological improvements in oil pipelines was driven by three factors.

• Consumer demand for petroleum in the prosperity of the Fifties.
  
  
• The growth of American industry that took place during the war.
  
  
• Increasing awareness of the importance of petroleum to the nation's security interests following wartime gasoline rationing. (More than 100 military bases and other facilities have their own direct connections with oil pipelines.)

Today, technology allows the manufacture of large diameter and much more efficient pipeline systems, and pump stations primarily driven by clean electrical power.

Nearly all of the vast volume of petroleum now transported by pipeline moves through highly automated systems - automation that has been a major factor in reducing the number and volume of pipeline spills. These computer-aided systems allow highly trained operators working in sophisticated central control rooms to monitor rates of flow, pressures and fluid characteristics. Fluctuations can be detected quickly, alerting operators to potential leaks and allowing them to shut down lines and dispatch crews to investigate.

Corrosion Prevention

Next to excavation accidents, corrosion is the next most common cause of pipeline spills. The pipeline industry has developed a range of technologies to eliminate or reduce corrosion.

* Cathodic protection is required on all interstate pipelines, and has been for decades. (This technique uses a constant low voltage electrical current, run through the pipeline to counteract corrosion.)

* Recent improvements in pipeline coating materials also help reduce the risk of a corrosion-related failure.

* The U.S. Department of Transportation is revising the pipeline safety regulations to incorporate more stringent corrosion prevention rules - a change supported by the oil pipeline industry.

Pigs and Smart Pigs

Pigs are cylinder shaped plugs of the same diameter as a particular pipeline. Two important accident prevention purposes of pigs include:

* Detecting potential leaks before they can happen. Smart pigs are fitted with sophisticated electronic sensors that can help locate some pipeline wall weaknesses before they can progress to the point of causing a leak.

* Scraping build-up off the interior wall of the pipeline to help prevent interior corrosion.

Central Coordination and Control

Pipeline systems are operated from highly computerized control centers which coordinate operations throughout the system - everything from rate of flow, to pressure, to opening and closing valves. The control centers also monitor devices that can alert operators to abrupt changes in operating parameters, providing a detection mechanism for fast response to emergency conditions. Satellite and telecommunications links connect control centers with facilities along pipelines to assure rapid response and constant monitoring of pipeline conditions.

Training

Pipeline companies constantly train control room operators and maintenance personnel for their specific pipeline systems. Each pipeline is unique, custom built to match the specific terrain, products and other factors that are peculiar to a system's operations. Safety drills are conducted so that operators and emergency response personnel know the details of their unique system.

This training and safety drilling is designed to protect against the human factors that can either cause accidents or make them worse once they happen. A new set of even more stringent qualification procedures has been adopted following a joint safety improvement effort between pipeline companies and the federal Office of Pipeline Safety.

Source: LandTech.org (http://www.landtech.org/)

Myths and Misleading Statements About Oil and Natural Gas Pipelines
-- Lois Epstein, P.E., Senior Engineer

Myth #1: Oil pipeline companies are doing everything they can to prevent leaks because lost raw materials and products cost companies money.

Facts: Petroleum and petroleum products are relatively inexpensive materials. Shutting down a pipeline to fix a leak is a costly undertaking. Installing one or more high-performance leak detection systems (multiple systems serve as backup and detect different types of leaks) can be expensive. So is testing pipelines on a periodic basis. Why should pipeline companies voluntarily pay to prevent and minimize leaks when they are not required to do so, when the cost of lost materials, cleanup, and government penalties combined generally is less expensive?

Myth #2: Pipelines are highly regulated.

Facts: The pipeline industry believes it is highly regulated because the rates it charges wholesale customers are set by the federal government. Nevertheless, pipeline industry profits are considerably higher than other industrial sectors (e.g., manufacturing) because older pipelines have been largely paid off. To illustrate how under-regulated this industry is, no permits are required for ongoing pipeline operations. Additionally, current pipeline regulations have the following serious deficiencies: there are no periodic testing requirements for natural gas pipelines; there are no leak detection, release shut-off, and overpressurization standards for oil or natural gas pipelines; there are numerous exemptions from the regulations for particular pipeline types; and, there is no ongoing reporting to the public about pipeline operations (e.g., frequency and type of pipeline tests). Moreover, while doing minimal enforcement itself, the Office of Pipeline Safety has not referred any cases to the Department of Justice for enforcement in years.

Myth #3: The most common cause of pipeline spills is third party damage.

Facts: The biggest single cause of oil pipeline leaks is corrosion (external plus internal). Third party damage, or damage caused by people who are not pipeline owners or operators (e.g., damage by a backhoe), is a serious issue and the most common cause of releases from natural gas distribution pipelines, which distorts the causal data when it is presented for all three types of pipelines (oil/hazardous liquid pipelines and natural gas transmission and distribution pipelines). Three-fourths of all releases from oil pipelines can be prevented by pipeline operators and their regulators, while only the remaining quarter are caused by "outside force" damage (third party PLUS weather-related, earthquake, landslide, and vandalism damages).

Myth #4: Pipelines are likely targets of terrorism, so information about pipelines should be kept off the Internet and away from the general public.

Facts: Nearly all oil and gas transmission pipelines are very low risk terrorist targets because they are located underground (an exception is the Trans-Alaska Pipeline) and are relatively easy to repair. Additionally, the information the public is most interested in, such as the frequency and type of internal testing, is of no interest to terrorists.

Misleading Statement #1: Given the amount of oil transported, pipelines spill only a negligible amount.

Reality: Quantity is not always the most relevant factor. The Exxon Valdez spilled less than 2% of one day's U.S. oil use, yet no one claims that small loss is acceptable because of where it spilled and the damage caused.

Misleading Statement #2: Pipelines are the safest way to transport petroleum.

Reality: There are no studies that show that pipelines are the most environmentally safe way to transport petroleum. "Safety" statistics are based only on human death and injury statistics. Oil pipeline releases can: contaminate drinking water supplies and crop, residential, and public lands; cause fish kills; break up wildlife habitat by creating pipeline right-of-ways; result in explosions and fires; and decrease property values because of spills and leaks. Additionally, comparing pipeline transport safety to other modes (e.g., trucks) is a false choice, because it avoids the question of whether pipelines can be made safer than they are today.

SOURCE: Safe Bellingham (http://www.safebellingham.org)