Transportation of oil BY DR. GHULAM ABBAS

Transportation of oil Once the crude oil has been extracted from underground, it must be transported from the oil fields (where oil has been discovered) to petroleum refineries (where the oil is further processed) to storage areas, where the petroleum products are stored for distribution and emergency reserves. These movement of oil are made easy using a number of different modes of transportation: Pipelines Ships– sea-going tankers, small tankers (vessels) and super-tankers Road trucks and Railroad cars

Refined oil separated from natural gas is transported by pipelines to another carrier or directly to a refinery. Petroleum products then travel from the refinery to market by tanker, truck, railroad car, or more pipelines. The major difficulty in the use of natural gas is transportation and storage because of its low density. Natural gas pipelines are economical, but are impractical across oceans. LNG carriers can be used to transport liquefied natural gas (LNG) across oceans, while tank trucks can carry liquefied or compressed natural gas (CNG) over shorter distances. Sea transport using CNG carrier ships that are now under development may be competitive with LNG transport in specific conditions.

Transportation of oil

Oil pipelines Oil pipelines can transport a very large amount of crude oil to very long distances. The pipeline is the most economical, efficient method for transportation of crude oil. The size of the pipelines can range up to 36 inches (92cm) in diameter and even larger, with some of the largest pipelines carrying more than one million barrels of oil daily. Pipelines cross all kinds of territories (land areas) and in all parts of the world.

They deliver over 14 billion barrels (more than 600 billion gallons) of petroleum per year. Care is also taken in the monitoring and construction for pipelines in consideration of environmental and safety issues. For example, one concern is to avoid the potential for fires and explosions in the offloading of crude oil by pipes onto tankers for transport to a refinery.

Ships, Oil Tankers (small ships) Tankers travel interregional water routes worldwide. There are various types of ocean-going tankers: oil tanker, parcel tanker (small sized vessels), combination carrier (designed to carry oil or solid cargoes in bulk), and supertankers. Tanker ranges in size from the small sized vessel to cargo sized tankers. These are also very economical and they can carry as much as 50 millions barrels of oil across the sea. The smallest tankers are used to carry weight from 10to 25000 tons.

Crude carriers are classed as either VLCCs (Very Large Crude Carriers) or ULCCs (Ultra Large Crude Carriers) and are designed to transport vast quantities of crude oil over many long and heavily traveled sea routes. But at smaller ports of the sea, these large cargos are unable to cross the sea. So crude oil is transferred from large tankers to smaller vessels, so that the can enter smaller sea-ports. In addition, care must be taken for the safe transport of chemical cargoes to avoid the greatest environmental risk.

Tank Trucks/Railroad Tank Cars Many petroleum products travel from refineries to markets by tank truck or railroad tank car. Tank trucks deliver petrol (gasoline) to service stations and heating oil to houses. These trucks can carry up to 300 barrels of fuel. Railroad tank cars can carry up to about 100 to more than 1,500 barrels of oil.

An oil-depot is an industrial facility for the storage of oil and petrochemicals and from which these products are usually transported to end users or further storage facilities. Oil-depots are usually situated close to oil refineries or in some areas these are attached to the pipelines from which they draw their supply. Most oil depots have road tankers to transport refined products to petrol stations and other users.

Storage of oil Generally crude oil is extracted from the oil-field then stored in the crude form until it is transported to the refineries. In the refinery, the crude oil has to be stored until processing capacity is available to refine it. Usually crude oil comes along with the sulfur content. Hence crude oil storage tanks have to be designed with special material to prevent corrosion resulting from sulfur contents.

Storage of oil Care must be taken by the operators of oil depots for safe storage and handling of the chemicals to avoid environmental risks. Fire protection is a primary risk, especially for more flammable products like petrol, and gases. So almost all storage of petroleum is of relatively short duration, only awaiting for transport or further processing. There are number of different types of verticle and horizontal above ground storage tanks, which can store crude oil, petroleum feed stocks and chemicals.