The petroleum industry's safety record of handling oil and its products in
Australia has been excellent and has been maintained throughout the last
two decades of rapidly increasing volumes produced and transported in
national waters. Oil spills from offshore production have been
insignificant and, while there have been some spills arising from shipping
accidents, none has had a lasting adverse impact on the marine
Nevertheless the Australian oil industry, aware of a concern about the
possible impact of oil spills on the marine environment, has stepped up
its efforts to protect the ecosystems surrounding its operations. Defence
against potential marine pollution is a combination of prevention and
cure. In addition to the introduction of more rigorous inspections and
safeguards on all its installations and tanker fleets, the industry has
established, one of the best equipped marine oil spill response and
training centres in the world. Sources of the oil in the sea
The risks and responsibilities associated with oil in the sea should be
put in their true perspective.
By far the highest contributor to oil in the ocean (about 30 per cent)
results from a mix of materials and wastes which make up urban run-off and
the discharge from land - based industrial plants. These materials reach
the sea via storm water drains, sewage outfalls, creeks and rivers.
Another seven per cent is oil which seeps naturally out of fissures in the
sea bed. Oil and tar stranded on the beaches of South Australia and
Western Victoria, for instance, was first noticed by European settlers
during the early 1800s. Now it is known to come from cracks in the ocean
seabed and is particularly noticeable after earth tremors in the region.
15 per cent of the oil in the sea is directly attributable to the world's
oil industry. Two per cent of this occurs in spills during the exploration
and production phase from rigs and platforms, and 10 per cent is
attributable to accidents involving oil tankers.
Another 35 per cent occurs during the operation of vessels other than
those used by the oil industry. Usually these are cargo vessels which may
be involved in collisions which spill fuel oil or they may discharge waste
oil from ballast tanks during a voyage.
The remaining 9 per cent of oil in the oceans is absorbed from the
Statistics show that historically the oil industry is directly responsible
for only a small proportion of marine oil spills, the oil companies -
individually and collectively - do not take the risk of spills lightly.
There are strict regulations governing all facets of their operations from
the exploration / production phase through to the delivery of refined
petroleum products. Exploration & production:
Almost 1,100 wells have been drilled and approximately 3,100 million
barrels of oil have been produced in coastal and offshore Australia. Only
about 600 barrels have been spilt in the marine environment from
exploration and production operations. This is equivalent to the volume
contained in a garden swimming pool and taken over a period of 25 years.
Most of these spills have involved less than 19 barrels of oil and in only
a very few cases has the oil reached the shore. In Australia the majority
of offshore exploration and production wells are drilled using water-based
drilling fluids. In the special instances when oil based fluids are
needed, strict control of the well circulatory system ensures that no oil
from the drilling fluid is discharged into the sea. In addition, to cope
with any sudden influx of pressure from an underground reservoir, every
well drilled is fitted with a series of valves called blowout preventers.
These immediately shut off the oil and / or gas flow in the event of an
emergency to prevent hydrocarbons reaching the surface in an uncontrolled
rush. As a result of improved technology, blow outs are virtually a thing
of the past.
Above the water line, special deck drains on each rig and platform collect
any waste fluids and channel them into settling tanks where oil is
separated out, put into containers and sent to shore for treatment and
The Australian petroleum industry is a world leader in the treatment of
water produced with oil through production wells offshore. Innovative
technology includes the use of hydrcyclones and air stripping techniques
to ensure the hydrocarbon content of formation water discharged into the
sea is well under the Government regulatory limit of 30 parts per million.
Coastal petroleum facilities:
All production and loading terminal facilities and refineries and land are
subject to strict government environmental protection policy requirements
concerning the purity of water discharge into the sea. Oil companies
ensure their discharges are well under the limit of 30 parts per million
in water. Oil transport: Undersea oil pipelines are wrapped in special
coatings to prevent corrosion and they are provided with an outer
protective coating of concrete which also gives the line sufficient weight
to keep it on the ocean floor. Often these lines are buried beneath the
seabed as an additional safeguard.
The integrity of oil tankers is more difficult to control because the
business of tanker operations is complex and fragmented. Oil company-owned
vessels make up only about 15 per cent of the world fleet. Oil
company-chartered tankers add another 20 per cent.
The vessels under oil company control are subject to stringent checks and
regulations concerning structural integrity, safety, maintenance and crew
training. Unfortunately, not all tanker owners, charterers and countries
registering tankers have the same high standards. Hence vessels vary in
quality and in the degree of maintenance and crew competence. However, oil
companies are working with ship certification societies, insurers and the
International Maritime Organisation to impose stricter control and
inspection of all tankers and their operations around the world. Through
rigorous vetting procedures, Australian oil companies seek to ensure that
only vessels of high quality are engaged for the trade in oil and
petroleum products in Australia.
Vessels owned and operated by the oil companies in Australia are subject
to stringent operating and maintenance requirements. A number of designs
have been introduced for new vessels - including double hulls and mid-deck
tank designs - to minimise oil loss from tankers in the event of a serious
accident at sea.
In the USA, the Oil Pollution Act (1990) has made it mandatory for all
tankers built after June 1990 to have double hulls if they are to enter US
ports. However, in other countries there is likely to be further debate on
design alternatives before regulations are formally adopted governing
construction of new vessels. The IMO and oil industry-funded researchers
are also investigating safety measures that can be applied to the existing
fleet. These include a redesigned ballast tank system, and a vacuum system
which, in the event of a ruptured hull, causes water to enter rather than
oil to spill out.
Major Spill Locations:
If, despite all precautions, an oil spill does occur off Australia's
coastline, the oil industry in association with government agencies, is
well prepared to minimise its impact on the environment.Organisations:
Australia has three interconnected oil pollution response organisations -
the Australian Marine Oil Spill Centre, the Marine Oil Spills Action Plan,
and the National Plan to Combat Pollution of the Sea by Oil.
Australian Marine Oil Spill Centre Ltd (AMOSC): is wholly owned subsidiary
of Australian Institute of Petroleum Ltd and is totally managed and funded
by the Australian oil industry. There are eleven participating oil
companies: Australian Petroleum Pty Limited, BHP Petroleum Pty Ltd, BP
Australia Ltd, Esso Australia Ltd, Hadson energy Ltd, Mobil Oil, Australia
Ltd, Santos Ltd, The Shell Company of Australia Ltd and Woodside Petroleum
The Centre was established in 1990 to provide the equipment and trained
personnel required to respond to a major oil spill off Australia's coasts.
Based on Corio Bay, near Geelong in Victoria, it houses over $10 million
of oil spill combat equipment and materials. This gear and the trained
staff are on call 24 hours a day and they can be at the scene of a spill
anywhere off Australia's coasts within 12-24 hours of being called out.
If additional back-up is needed AMOSC can call on international aid from a
similar organisation based in Singapore (East Asia Response Ltd) as well
as the world's largest spill organisation (Oil Spill Service Centre)
located in Southampton, England. The latter has its own cargo plane on
standby and can be at most locations within 48 hours of receiving a call.
AMOSC also has a purpose-built training centre where regular courses are
held in oil response techniques. The Centre trains between 200 and 300 oil
industry and government safety personnel each year. Marine Oil Spills
Action Plan (MOSAP): was established by the oil industry in 1971 to enable
an individual company to obtain assistance from other companies in
combating a spill larger than it can handle with its own resources. Like
AMOSC, MOSAP is supervised and funded by the oil industry through the
Australian Institute of Petroleum.
The industry has provided equipment and clean-up materials at each port
around Australia where oil is handled in bulk. A minor spill will be
handled by the oil company concerned using the equipment available to it
at or near the site. MOSAP is activated if a spill is beyond the
capability of the company concerned.
If the spill is of major proportions, contact will be made with AMOSC and
the Australian Maritime Safety Authority for assistance.
National Plan to Combat Pollution of the Sea by Oil (NATPLAN) has been in
operation since October 1973. It is a combined effort by State and Federal
organisations and the oil industry. Oil spill combat equipment is provided
at various locations round Australia and a training program is conducted
by the Australia Maritime Safety Authority. Funding for NATPLAN is based
on the 'polluter pays' principle and a levy is placed on commercial
shipping using Australian ports. These funds provide for the maintenance
and administration of the Plan and allow for a contingency to cover costs
not attributable to the polluter, or which the polluter is unable to meet.
No two oil spills are the same because of the variation in oil types,
locations and weather conditions involved. However, broadly speaking,
there are four main methods of response.
Leave the oil alone so that it breaks down by natural means.
Contain the spill with booms and collect it from the water surface
using skimmer equipment.
Use dispersants to break up the oil and speed its natural
Introduce biological agents to the spill to hasten biodegradation.
Processes Following a Spill:
Often the response involves a combination of all these approaches.
Natural dispersion: If there is no possibility of the oil polluting
coastal regions or marine industries, the best method is to leave it to
disperse by natural means. A combination of wind, sun, current and wave
action will rapidly disperse and evaporate most oils. Light oils will
disperse more quickly than heavy oils. Booms and skimmers: Spilt oil
floats on water and initially forms a slick that is a few millimetres
thick. There are various types of booms which can be used either to
surround and isolate a slick, or to block the passage of a slick to
vulnerable areas such as the intake of a desalination plant or fish farm
pens or other sensitive locations.
Boom types vary from inflatable neoprene tubes to solid, but buoyant
material. Most rise up about a metre above the water line. Some are
designed to sit flush on tidal flats while others are applicable to deeper
water and have skirts which hang down about a metre below the waterline.
Skimmers float across the top of the slick contained within the boom and
suck or scoop the oil into storage tanks on nearby vessels or on the
However booms and skimmers are less effective when deployed in high winds
and high seas.
Dispersants: These act by reducing the surface tension that stops
oil and water from mixing. Small droplets of oil are then formed which
helps promote rapid dilution of the oil by water movements. The formation
of droplets also increases the oil surface area, thus increasing the
exposure to natural evaporation and bacterial action. Dispersants are most
effective when used within an hour or two of the initial spill. However
they are not appropriate for all oils and all locations. Successful
dispersion of oil through the water column can affect marine organisms
like deep water corals and seagrass. It can also cause oil to be
temporarily accumulated by subtidal seafood.
Decisions on whether or not to use dispersants to combat an oil spill must
be made in each individual case. The decision will take into account the
time since the spill, the weather conditions, the particular environment
involved and the type of oil that has been spilt.
Most of the components of oil washed up along a shoreline;can be broken
down by bacteria and other micro-organisms into harmless substances such
as fatty acids and carbon dioxide. This action is called biodegradation.
The natural process can be speeded up by the addition of fertilising
nutrients like nitrogen and phosphorous which stimulate growth of the
However the effectiveness of this technique depends on factors such as
whether the ground treated has sand or pebbles and whether the fertiliser
is water soluble or applied in pellet or liquid form.