2. Make up questions to the answers.

1. Gas and oil pipelines are very different in their design and modes of operation.

2. The quantity of gas transported is greater when the gas is compressed to a high density.

3. Between compressor stations some expansion and cooling will occur.

4. The Alcan gas pipeline has not been built because of a changing oil and gas market.

5. The pipeline going from the seabed to shore encounters severe problems with waves and floating iceproblems.

2. True or false?

1. Gas and oil pipelines are the same in their design and modes of operation.

2. Gas has a high volumetric heat capacity, cools quickly when compressed, and warms quickly when expanded.

3. The quantity of gas transported is less when the gas is compressed to a high density.

4. Gas will get liquid when passing through the compressor system.

5. Between compressor stations some expansion and cooling will occur.

6. Deliberate warming of the gas is not necessary when it is transported through a pipeline buried in the permafrost.

7. The gas in some pipelines is at a pressure as great as 14 megapascals.

8. After compression, the hot gas must be warmed by ref- rigeration.

2. Fill in the gaps and read the extract.

0...1 pipelines are made from st...el or pl...stic tubes with inner diam...ter typically from 10 to 120 cm (about 4 to 48 inches). Most pipelines are buried at a t...pical dep...h of about 1-2 metr...s (about 3 to 6 feet). The o...l is kept in mo...ion by p...mp stations along the pipeline, and usually fl...ws at speed of about 1 to 6 m/s. Multi-product pipelines are used to transport two or more different products in se- quence in the same pip...line. Usually in multi-product pipelines there is no p...ysical separation between the different prod...cts. Some mi...ing of adjac...nt products occurs, producing inter-

face. This interface is removed from the pip...line at re- ceiving facilities and segregated to pre...ent contamination.

Did you know that...

...Crude oil contains varying amounts of wax, or paraffin, and in colder climates wax buildup may occur within a pipe­line. Often these pipelines are inspected and cleaned using pipeline inspection gauges pigs, also known as scrapers or Go- devils. These devices are launched from pig-launcher stations and travel through the pipeline to be received at any other station down-stream, cleaning wax deposits and material that may have accumulated inside the line.

....For natural gas, pipelines are constructed of carbon steel and varying in size from 2 inches (51mm) to 56 inches (1,400 mm) in diameter, depending on the type of pipeline. The gas is pressurized by compressor stations and is odorless unless mixed with a mercaptan odorant where required by the proper regulating body.

2. Complete the sentences using information in the right — hand column.

Give the title to the extract and discuss the problem.

Unlike crude oil, natural gas...	.. .in a manner similar to crude oil.
Gas begins that journey...	...is generally delivered directly to the consumer by pipeline.
Gas wells are connected to small- diameter (five centimetres to 15 centimetres; two inches to six inches)...	...that are mounted on moveable platforms and that remove impurities and water from the gas, to large gas plants that also remove sulphur and carbon dioxide.
Gas processing facilities, usually referred to as gas plants, vary in size from small compression facilities...	.. .gathering systems that take the gas to a gas processing facility.
Some gas plants also extract ethane,...	.. .into the transmission system which consists of steel pipe from 50 centimetres (20 inches) to more than a metre (39.4 inches) in diameter.
The generally diy gas may then be compressed prior to moving...	.. .propane, and butane, which are referred to as natural gas liquids or NGLs.
Gas flows through the system from areas of high pressure...	.. .along the pipeline to increase line pressure which is reduced due to friction of the gas moving through the pipe.
Compressor stations are placed at regular intervals...	.. .to areas of low pressure through the use of compressors, turbines similar to jet engines that increase the pressure of the gas up to 10,300 kilopascals (1,500 pounds per square inch).

Check yourself!