is petroleum? What are oils? What are hydrocarbons?
means "rock oil", from the Greek petros/Latin
petra (rock), and the Greek elaion/Latin
oleum (oil). The term petroleum is nowadays used
as a common denotation for crude oil (mineral oil) and natural
gas, i.e., the hydrocarbons from which various oil and gas
products are made. Petroleum, then, is a collective term
for hydrocarbons, whether solid, liquid or gaseous.
of natural gas and crude oil have formed over millions of
years as plants and animals have been broken down and undergone
chemical change at high temperature and pressure. That is
why oil and natural gas (and coal) are referred to as "fossil
fuels". One finds petroleum in porous rock-forming
large sedimentary basins, where the oil and gas has been
trapped by some kind of barrier thereby forming a reservoir.
pumped out of a well on land or in the seabed, crude oil
is a complex mixture of thousands of different chemical
components, mainly organic compounds hydrocarbons
which usually make up about 95 per cent of the crude
oil (however, hydrocarbon contents as low as around 50 per
cent also occur). Before being used as fuel (for
energy generation, machinery and vehicles), or as a raw
material in the petrochemical industry, crude oil is refined
into different fractions. At the refinery, crude oil is
separated into light and heavy fractions, which are then
converted into various products, such as petrol, diesel
oil, jet fuel.
is oil and gas extracted from the seabed (offshore extraction)?
are drilled into the seabed to the depth of the oil reservoir.
The crude oil pumped from wells is a mixture of natural
gas, water (formation water and/or production water) and
hydrocarbons. The gas is separated from the oil and water
and further treated and either flared off or used as natural
gas for various purposes. Water and solid particles are
removed from the oil component of the crude oil.
are "refined" oil products?
delivered to a refinery, the crude oil is subjected to distillation
and other separation and refinement processes. The resulting
products from these processes are a number of fractions
with different characteristics and ranges of use:
raw gasoline (benzine and naphta), the end product
of which is petrol (gasoline);
intermediate distillates, the end products of which
include light gas (fuel) oil, diesel oil, aviation fuels,
heavy distillates, giving end products like heavy
gas (fuel) oil for cracking processes, as well as lubricants,
residues, the end products of which are heavy fuel
oils, asphalt (bithumen), tar and coke.
oil products are, roughly, divided into the four main categories:
Fuels. Lubricants. Vaxes. Asphalt (bitumen). Fuels is the
largest of these categories, with the largest product volumes
and number of products. Oil is also the raw material for
industry to manufacture thousands of industrial and consumer
products. Crude oil constitutes the raw material for production
of plastics (polymers). Furthermore, oil is used for the
manufacture of products such as rubber, paints, fertilizers,
detergents, dyes, textiles, solvents, medicine, ink, pesticides,
varnishes and much more.
MORE about characteristics]
MORE about use]
tanker accidents the major source of marine oil pollution?
Although every major oil spill from a tanker or a rig, hitting
coastal areas and beaches and killing marine life and seabirds,
is a tragedy and causes much damage, it has been estimated
that oil spills in conjunction with tanker accidents or
oil platform blowouts account for a minor part, approximately
10-15 per cent, of the total annual oil input of oils to
the marine environment. According to a recent report by
the National Research Council of the U.S. National Academy
of Sciences, the total input of oils to the marine environment
is about 1.3 million tonnes per year. The main categories
of sources that contribute to this input are: natural
seeps 46%; discharges from consumption of
oils (operational discharges from ships and discharges
from land-based sources) 37%; accidental spills
from ships 12%; offshore extraction of
although the total amount of oil entering the ocean from
tanker and accidents and blowouts might be lower than what
is generally believed, every effort must be made to reduce
that figure even more. Unlike natural seeps, which we cannot
stop from happening, we can do much to prevent and avoid
all kinds of oil spills resulting from human activities,
including accidents. This holds true for all operational
discharges from ships at sea, and from all discharges of
oils from land-based sources. And it holds true for both
discharges of "wet" oil products and for hydrocarbons
in gaseous form.
MORE about sources of oil pollution]
MORE about quantities]
tankers be made wreck-proof?
Even with the latest developments in ship's design, with
double hulls etc., accidents/collisions and groundings
are likely to be occurring also in the future, with more
oil spills of varying sizes as the result. But much can
be done to improve safety, because it is not merely a matter
of technical solutions in terms of design. See below:
What can be done to prevent marine oil pollution.
then, does oil enter the marine environment in other ways?
of oil input to the marine environment are often divided
into natural, sea-based and land-based sources.
sources of oil in the marine environment are places
where crude oil and natural gas seep naturally out of fissures
in the ocean seabed and eroding sedimentary rock. These
seeps are natural springs where liquid and gaseous hydrocarbons
leak out of the ground (like springs that ooze oil and gas
instead of water).
Land-based sources include discharges of untreated or
insufficiently treated municipal sewage and storm water
(urban runoff); discharges with rivers; discharges of untreated
or insufficiently treated waste water from coastal industries;
accidental or operational discharges of oil from coastal
refineries, oil storage facilities, oil terminals, and reception
facilities; emissions of gaseous hydrocarbons from oil-handling
onshore facilities (terminals, refineries, filling stations)
and from vehicles exhausts (traffic).
sources include accidental oil spills from tankers and
other commercial vessels, grounded and abandoned vessels,
oil platforms (blowouts), and pipelines. Sea-based sources
are also deliberate, operational discharges of oil from
all kinds of commercial vessels (ship- or cargo-related
discharges), oil platforms, and pipelines. Also, emissions
of gaseous hydrocarbons from tankers and pleasure craft,
and from oil extraction are examples of such sources, as
are other kinds of ship-related activities (dry docking,
scrapping), and dumping of oily waste, etc.).
happens to oil spills in sea water?
oil spill in the marine environment is unique, because every
time oil enters the sea a number of factors will decide
the physical, chemical and biological degradation of the
oil in that particular area. Some of these factors are the
composition (what kind of oil) and amount of oil discharged;
the quantity and duration of the discharge/spill; the time
of year at which it occurs; the temperature of the air and
the receiving water body; the weather conditions; the properties
of the shore line (rocky, sandy, mud flats, mangroves, etc.);
the amount of oil-degrading micro-organisms in the area;
and the supply of oxygen in the water. Once the oil is in
the sea water, a number of things can happen these
processes are called weathering, spreading, dispersion,
evaporation, dissolution, biodegradation, sedimentation,
emulsification, dissolution, oxidation, biodegradation,
and much more.
oil in the sea only kill seabirds?
oil spills can harm wildlife in a number of ways. However,
it should be realized that there is no obvious relationship
between the amount of oil spilled in the marine environment
and the impact on wildlife. The impact will depend on such
factors as the spread of the oil slick, the type of oil
spilled, the location of the spill, the timing/season when
the spill occurs, the sensitivity of the regional environment
(e.g., species composition, proximity to bird breeding colonies,
etc.) and the nature, toxicity and persistence of the oil.
birds are particularly sensitive to oil. In a cold climate
an oil spot the size of 2-3 sq. centimetres can be enough
to kill a bird. The insulating effect of the plumage is
destroyed by the oil, and the bird freezes to death (hypothermia).
If a bird gets smeared with a lot of oil this may clog its
feathers and make it impossible for the bird to fly.
mammals (seals, polar bears, sea otters and others) living
in cold water areas can also die of hypothermia as their
fur loses its insulating ability once it has been covered
in oil. Fur seals and sea otters are examples of such species.
Marine mammals like whales and dolphins can be damaged in
different ways by oil when they inhale large quantities
of oil-contaminated water.
congested lungs, intestinal or lung hemorrhage, liver and
kidney damage, are examples of other effects caused when
birds or marine mammals inhale or ingest oil.
turtles these nest on sandy beaches, which if oiled can
lead to a number of problems, e.g., contamination of eggs,
newly hatched become oiled on their way over the beach to
the water, irritation of mucous membranes (in nose, throat
fish and shellfish can be damaged by oil in the water, as
oil products are toxic to larvae.
on the seabed (bottom-living organisms) will also be affected,
once the oil through various processes is transported to
deeper water layers.
for different habitats, oil damage will vary due to the
characteristics of the coastline and its on-land and underwater
vegetation: very different things will happen to rocky shores,
sandy beaches, mangroves, mud flats, marshes, coral reefs,
MORE about wildlife]
MORE about habitats]
a damaged coastal habitat and damaged wildlife ever recover
from an oil spill?
they can, but it can be and often is a matter
of many, many years, even decades. Again, every situation
is unique and depending on the particular conditions and
circumstances in that area and the characteristics of the
spill (see above on the fate of oil in the water). Some
areas might recover in a matter of weeks, whereas others
will need up to 20 years. The recovery of an ecosystem will
also depend on the share of important populations being
killed off or affected by acute poisoning.
an oil spill affect human health?
Volatile components (the strong smell that you feel from
oil products is due to such gases that evaporate) of oil
can burn eyes, burn skin, irritate or damage sensitive membranes
in the nose, eyes and mouth. Hydrocarbons can trigger pneumonia
if it enters the lungs. Benzene and other light hydrocarbon
can damage red bloods cells, suppress immune systems, strain
the liver, spleen and kidneys. Generally, refined products
tend to be more toxic, but people who clean up shorelines
from oil spills must protect themselves from inhaling these
gases also when it is a matter of crude oil. Some of the
light fractions of oil, such as the aromatic components
(e.g., benzene), are also known to cause cancer and are
very toxic to humans.
MORE about human health]
pays for the damage caused by oil spills?
oil spill, particularly a large one, can result in serious
and long-term economic repercussions on the coastal communities
of the affected area, particularly in regions which are
heavily depending on coastal and marine resources. Fisheries
(including fish farming and shellfish) and tourism are the
two sectors that are likely to suffer the most. Also, it
is a shock and a cause of great sadness and distress for
people who see their shores get destroyed by oil, even if
the area can eventually be cleaned. Thus, the concept of
"paying" is not just a question of money.
it comes to paying in terms of giving economic compensation
for the damage caused by an oil spill from a tanker, there
is an internationally agreed system of compensation. But
ultimately, the costs will to a great extent be carried
by nations, coastal municipalities, and individuals.
MORE about global agreements on compensation, conventions
MORE about economy and human health]
can be done to prevent marine oil pollution?
land-based sources? Better management of stormwater,
better treatment of household sewage and industrial wastewater,
more efficient burning in boilers (power plants), more efficient
collection of waste oils from petrol stations and households,
additional measures to reduce discharges from industrial
processes and installations, including refineries and other
sea-based sources? A number of additional measures could
be envisaged to further improve the safety and environmental
performance of tankers and other vessels, and of offshore
oil rigs. Well-trained crews, strict fire safety regulations
on board, better navigational equipment, traffic separation
schemes in busy shipping corridors, and frequent inspection
of ships (particularly older ones), are all measures that
could and should be taken to further minimize the risks
of collisions/accidents and groundings. Further improvements
of ship's design will also help to minimize the size of
a spill (and hopefully altogether eliminate the risk of
a spill) if an accident occurs. Better facilities in ports
for ships to leave their oily liquid waste and solid oily
waste are also an important measure to ensure that the wastes
are treated in an environmentally acceptable way.
see big rescue operations at sea and shore cleanup operations,
but can they really stop anything?
there are several methods to be used at sea and on land,
but no miracles can be performed and an oil spill is always
a cause of damage to the environment and the communities
that are affected.
about combatting at sea]
MORE about shoreline cleanup]
to the International Tanker Owners Pollution Federation
(ITOPF), "given the difficulties of cleaning up oil
at sea, many oil spills result in contamination of shorelines".
ITOPF points out that initial clean-up responses to a spill
at sea are "often based upon the use of dispersant
chemicals or the containment and recovery of oil using booms
and skimmers. Whilst these techniques can be of use in the
right circumstances, there are many difficulties associated
with employing them effectively. The type of oil and concerns
over potential impacts of dispersed oil can preclude dispersant
use. For example, they are not effective against many commonly
transported oils which have a high viscosity, and soon become
ineffective against lighter oils because natural weathering
processes or the formation of water-in-oil emulsions greatly
increases oil viscosity, often very quickly (a few hours
to one to two days). The application of dispersants to treat
large quantities of spilled oil also requires specialised
equipment and extensive logistical support. Containment
and recovery is limited by sea conditions and the relatively
small oil encounter rate which the available systems can
achieve. Together, these factors usually mean that only
a small fraction of a major spill can be dealt with at sea,
and it is almost inevitable that oil will threaten coastal
resources and contaminate shorelines".
also summarizes that "it is important to start removing
oil promptly from contaminated shorelines because as time
passes and the oil weathers, it will stick more and more
firmly to rocks and sea walls, and may become mixed with
or buried in sediments. Reliance is frequently placed on
locally-available equipment and manpower, rather than specialised
equipment. Good organisation and management are the key
to effective clean-up."
I myself do anything at all to prevent further marine oil pollution?
there are plenty of things that you as an individual can
do or rather make sure that you don't do. Become
you can see from the list of land-based sources and activities,
and also from the sea-based sources when it is a matter
of recreational boating, individuals and households can
certainly contribute to the important efforts to minimize
the input of hydrocarbons/oils to the marine environment.
very careful with what you do with oil-containing waste
from your household. Don't flush it in the sewers or pour
it into the storm sewer systems street gutters and
storm water systems still often drain directly to lake,
streams, rivers, and wetlands. Clean up spilled oil on the
ground and don't hose it into the street, where they can
eventually reach local streams and lakes.
you are in charge of a workplace where oil products are
handled, either as the main activity or as part of other
activities, introduce routines for recovering, storing and
disposing of used oils and other residues in a safe and
environmentally-friendly way. Out of sight might be out
of mind, but the oil you pour into sewers and storm water
systems will not disappear, only cause damage somewhere
used engine oil for recycling. If your community doesn't
supply services for recovery and recycling, find other ways
of at least storing the used oil in a safe place instead
of pouring it into sewers or street gutters.
you have a motor boat (leisure craft) with a two-strike
engine, replace that engine with a four-stroke engine! As
you can see from the list of sea-based sources of oil to
the marine environment, two-strike engines are quite terrible
in that respect.
your private consumption of fossil fuels, including oils,
by using collective means of transportation whenever possible.
If you have a car, be careful with maintenance (older cars
do not necessarily have to drib and drab oil on streets,
or "burn oil" instead of petrol/gas).
more about all the places and activities in everyday life
where oil products are handled and used. The more you know
about all the possible land-based and sea-based sources
of oil, and how easily oil actually enters the marine environment
because of ignorance or negligence, the more you can also
see ways of avoiding pollution and guide other people
to do the right thing.