Read the text and translate it. Gas fields are often located far from major consumption centers; consequently, the gas has to be transported
Gas fields are often located far from major consumption centers; consequently, the gas has to be transported, although chemical industry transformation plants are frequently installed in the vicinity of production fields. Transportation of natural gas depends upon its form – in a gaseous form it is transported by pipeline under high pressure, and in a liquid form it is transported by boat.
Large gas pipelines enable gas to be transported over thousands of kilometers. Examples are the North American pipelines, which extend from Texas and Louisiana to the northeast coast and from the Alberta fields to the Atlantic Seaboard.
Transportation pressure is generally 70 bars (70 kilograms per square centimeter [1,000 pounds per square inch]) because economic studies, in keeping with technological advances, have shown that transportation costs are at a minimum for pressures of this magnitude. Pipeline diameters for such long-distance transportation have tended to increase from an average of about 60 to 70 centimeters (24 to 29 inches) in 1960 to a size of 1.20 meters (about four feet). Some Soviet projects involve diameters of more than two meters (6.5 feet) and pressures of about 40 bars (41 kilograms per square centimeter [580 pounds per square inch]).
Because of pressure losses, the pressure has to be boosted at regular intervals to keep a constant flow rate in the pipeline, and economic surveys indicate that a compression station should be located every 80 or 100 kilometers (50 or 60 miles) in order to obtain maximum flow under the most economically advantageous conditions. At greater intervals, the pipeline is doubled in size if the gas flow is to be increased.
Despite the high pressure and circulation rates of 10 to 15 meters (33 to 49 feet) per second for gas, the energy carried by a gas pipeline is still one-third or one-half as much as that carried by an oil pipeline because one cubic meter of oil contains as much energy as 1,000 cubic meters (35,000 cubic feet) of natural gas.
Petroleum prospecting has revealed the presence of large gas fields in Africa, the Middle East, Alaska, and elsewhere. Transportation from such areas is effected by boat. The gas is liquefied to – 160° C (-256° F) and transported as oil in tankers designed especially for this purpose. One cubic meter of liquid natural gas is equivalent to 600 cubic meters (21,200 cubic feet) of gas at atmospheric pressure, with the specific gravity of the liquid being relatively low (about 0.55).
This technique has developed very quickly since the first industrial operations involving it began in 1965 from Africa to Great Britain and France. Two other lines opened up in 1970, the first from Libya to Spain and Italy, and the second from Alaska to Japan. Since then other large-scale projects, including lines from African, South American, and Indonesian fields to the United States, Europe, and Japan have been undertaken.
After 1965, when methane tankers with a capacity of 20,000 cubic meters (706,300 cubic feet) began to be used, the size of these ships rose to 90,000 and even 120,000 cubic meters (3,178,000 and 4,237,000 cubic feet), an increase that enabled them to carry from 50,000,000 to 70,000,000 cubic meters (1,800,000^000 to 2,500,000,000 cubic feet) of gas per trip.
Vocabulary
consumption [kənˈsʌmpʃən] – потребление
consequently [ˈkɒnsɪkwəntlɪ] – следовательно; поэтому
frequently [ˈfriːkwəntlɪ] – часто
install [ɪnˈstɔːl] – располагать; размещать; устанавливать
vicinity [vɪˈsɪnɪtɪ] – близость; окрестности
enable [ɪˈneɪbl] – давать возможность
pressure [ˈpreʃə] – давление
boost [buːst] – поднимать; помогать подняться
reveal [rɪˈviːl] – открывать; обнаруживать; показывать
relatively [ˈrelətɪvlɪ] – относительно; сравнительно
undertake [ˌʌndəˈteɪk] – предпринимать; совершать
increase [ˈɪnkriːs] – возрастание, рост; прибавление; прирост
tanker [ˈtæŋkə] – танкер; нефтеналивное судно
Comprehension task