Canada's pipeline system reaches over 700,000
kilometres, and has four main categories. The first
category is local or provincial companies or
co-operative run natural gas distribution lines to
deliver the gas to homes, businesses, and small
industry. Flow lines or gathering lines are the way
that natural gas and oil are moved from wellheads to
oil batteries and production facilities. Feeder
lines transport crude oil and other liquids from one
processing facility to the transmission lines.
Transmission pipelines are used for transportation
of crude oil and natural gas in a province, the
nation, or internationally.
In every case, the building of these pipelines
must be carried out carefully and involves years of
planning. After consultation, negotiations with land
holders and environmental assessments have been
conducted; approval is given by the federal and
provincial governments. The construction is carried
out in four stages: clear the land, dig the trench,
deliver the pipe, and then weld the pipes together. The
straightforward stages of construction must
continuously address the concerns for the integrity
of the pipeline. Offshore pipeline are buried in
trenches on the bottom of the ocean.
In oil pipelines, powerful electric motors drive
the centrifuge pumps on the lines, sending the oil
through the pipes at four to eight kilometres an
hour. Trunk lines carry different types of crude
oil, natural gas and refined products where all the
products are sent in batches. They do not mix due to
hydraulics and are sent to separate storage
facilities. The world's largest crude oil pipeline,
owned by Enbridge Pipelines Inc., transports oil
from Norman Wells in the Northwest Territories,
through Alberta, and then to Ontario and the United States.
Natural gas pipelines ship the gas by using
turbines to spin the centrifuge pumps that compress
the gas. The natural gas travels faster than oil,
moving up to forty kilometres per hour. The largest
carrier is TransCanada Pipelines Ltd. Alberta Gas
transmission division. TransCanada also owns the
largest natural gas interprovincial pipeline in
Canada, stretching from Alberta to Quebec. In
British Columbia, Duke Energy Gas Transmission
operates their lines, and TransGas Limited operates
the Saskatchewan lines.
All design and construction decisions are guided
by Canadian Standards Association, International and
all levels of government regulators. They are
concerned that the pipe is buried deeply enough,
that it is the correct thickness, that is the
correct material, and other issues. The importance
of proper welding cannot be overstressed.
Non-destructive examinations are carried out to make
sure the pipe joints are welded to specifications.
The examinations use ultrasonic and radiography to
see if there are any imperfections in the weld.
Pipeline companies also use systems to avoid
leaks and spills, which would contaminate the soil
or fresh water deposits nearby. Computer systems on
pipelines can detect pressure drops. Smart Pigs are
devices that conduct internal inspections of the
pipeline detecting erosions or leaks. Pipeline
faults called “stress corrosion cracks” cause
pipeline failures are a problem that is being
addressed by agencies including the National Energy
Board. Another danger is damaged caused by people
digging and hitting the line. The “Call Before You
Dig" program is important in reducing these
accidents.
 |
Ribbons of Oil
Pipeline construction in Canada receives its legal mandate from the Pipe Line Act. In this excerpt from the JuneWarren publication, The Great Canadian Oil Patch: The Petroleum Era from Birth to Peak, author Earle Gray retraces the debate that led to the passing of the Pipe Line Act by Parliament in 29 April, 1949, and reveals the challenges and controversy involved with the construction of the Interprovincial Pipeline (IPL). Read more… |
|