Few would deny that the oil spill in the Gulf of Mexico was an accident of
almost epic proportions – one that cost human lives and whose toll on the
environment, wildlife, businesses, and individual livelihoods mounts by the day.
So it’s no surprise that the oil industry’s operations have come under
increased scrutiny of late. But it turns out that not all oil industry practices
carry the same kinds of risks as deepwater drilling. For example, when it comes
to transporting its product, the oil industry, for the most part, uses one of
the safest modes available: the pipeline.
The first crude oil pipeline was laid in Pennsylvania in 1865. The line was
modest – only two inches in diameter and four miles in length – and ran
directly from the wellhead to a railroad loading station. This represented a
significant advance over the previous practice of transporting oil in wooden
kegs loaded on horse-drawn wagons. The success of this new line led to others,
and by 1920, U.S. pipeline mileage had tripled. Growth continued at a moderate
pace until the early stages of World War II, when 48 U.S. oil tankers were sunk
by German submarines. The tankers’ vulnerability quickly led to an expansion
of land-based lines moving oil from Texas and Oklahoma to the Eastern Seaboard,
and by 1946, there were 140,000 miles of pipeline in the United States, all
controlled by oil companies.
Today, there are approximately 200,000 miles of oil pipelines throughout the
country, and this $31 billion system moves about two-thirds of the oil
transported in the United States. Water carriers move about 28 percent, with
motor and rail carriers sharing the remaining 6 percent. To fully appreciate the
volume of oil handled through the pipeline system, consider the following: A
modest-sized pipeline will transport about 150,000 barrels daily. This volume by
road would require 750 tanker trucks daily, delivering a load every two minutes
around the clock. Moving it by rail would require a 75-car train, with each tank
car carrying 2,000 barrels, arriving and unloading every day.
One of the most important pieces of equipment in the pipeline universe is the
pipeline inspection gauge, or pig. During the process of pigging, this
tool, the diameter of which matches the diameter of the line, is propelled by
the pressure of the product in the pipeline. It is used for several different
operations, including the physical separation of different types of liquids,
recording geometric information, inspection of walls, and cleaning.
The original pigs were made of straw wrapped in wire and squealed when they
moved through the pipe. The term "pipeline inspection gauge" was later
created as a backcronym to fit the squealing pig analogy.
Although pipelines can be targets of vandalism or sabotage, the greatest
threat to their integrity is damage from excavations. According to the Office of
Pipeline Safety, 43 percent of the oil lost from pipelines results from careless
digging. The next most common cause of spills is corrosion. To reduce this risk,
the pipeline companies have developed a number of technologies, including the
pigs. These tools must be utilized, however, to be effective. On Aug. 6, 2006,
BP acknowledged that there had been no pig inspection since 1992.
Although many pipelines are 40 to 50 years old, there is no evidence to
suggest they represent a significant threat, assuming proper maintenance. This
subterranean transportation system, the largest in the world, is recognized as
the safest and most economical method of moving huge quantities of oil and gas
from production points and refineries to users.