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Oil Transportation TopicsHow Are Crude Oil and Refined Products Transported?
Waterborne Transportation
Tankers range in size from the small vessels used to transport refined products to huge crude carriers. Tanker sizes are expressed in terms of deadweight (dwt) or cargo tons. The smallest tankers are General Purpose which range from 10 to 25,000 tons. These tankers are used to transport refined products. The Large Range and Very Large Crude Carriers (VLCC) are employed in international crude oil trade. The size of tanker that can be used in any trade (commercial voyage between a port of origin and destination) is dependent on the tanker's length and loaded depth and the size of the loading and unloading ports.
As of 2006:
The following table illustrates the costs between different locations.
[Source: Average data for February 2009 as published in the Oil & Gas Journal from Drewry Shipping Consultants Ltd.] As illustrated in the above chart, types of cargo and distance determined freight rates. Note the different costs for distillate deliveries to New York from the Caribbean and N. Europe. Also see the differences among shipments of crude oil to Houston from N. Europe, West Africa and the Persian Gulf. The size of the ship used also affects costs as seen by the costs to deliver RFO (residual fuel oil to Houston from the Caribbean.
Oil Spills
U.S. tankers are constructed and operated under strict regulations. Companies use a communication network of telephone, telex, and satellite systems to locate their tankers. On board the ships, crews follow strict safety measures, minimizing loss of personnel and product. Automatic collision avoidance systems track approaching ships, alerting a tanker to an obstruction on its course. There have been many developments in improving the tanker operations to reduce the frequency and amount of oil spilled. At one time, tankers discharged dirty ballast water (oil mixed with sea water into the ocean). Improvements have been made in tanker design and now discharge of oily water is now illegal. In the past, after oil tankers discharged their cargo, they pumped sea water into the oil storage containers to provide ballast for the return trip. When the ship arrived at the loading port, this oily ballast was discharged into the ocean and crude oil was pumped into the ship's containers. Now new tankers have segregated ballast tanks. These ships have tanks that are solely used for ballast and water and oil are kept apart.
Storage Facilities
The amount of crude oil and refined products in storage is reported by Energy Information Administration. While the actual volume is important, a better index is the number of days of supply available. This number reflects the volume that can be supplied to run refineries (crude oil) or the volume of refined products that are available to meet demand.
Oil Pipelines
Crude oil is collected from field gathering systems consisting of pipelines that move oil from the wellhead to storage tanks and treatment facilities where the oil is measured and tested. From the gathering system the crude oil is sent to a pump station where the oil delivered to the pipeline.
A pipeline may handle several types of crude oil. The pipeline will schedule its operation to ensure that the right crude oil is sent to the correct destination. The pipeline operator sets the date and place when and where the oil is received and the when the oil will arrive at its destination. Crude oil may also move over more than one pipeline system as it journeys from the oil field to the refinery or shipping port. Storage is located along the pipeline to ensure smooth continuous pipeline operation.
Batching is used to move two or more different liquids through the same pipeline. The liquid are transported in a series of batches. The adjoining batches mix where they come into contact. This mixed stream may be sent to refinery for re-refining, sold as a lower valued product such as a mixture of premium unleaded gasoline with regular unleaded gasoline, or sold as mixture. Many product pipelines have standard product specifications. This allows one company to ship gasoline over the line and get not be concerned whether he receives gasoline from that same batch. Its all the same quality. Individual additive packages are added at the distribution terminals.
Copyright
2000 |
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