Geology. Козлова Е.П. - 35 стр.

        Because of the widespread distribution of petroleum reservoirs it was possible
for new discoveries to be made at a rapid rate through the 1950s. As one result, there
was little incentive for the development of efficient production techniques. Because
little use had been found for the natural gas produced along with crude oil, the gas
often burned at the wells. Such wasteful practices were gradually halted, partly by the
increasing difficulty of finding new petroleum reservoirs and partly by the increased
uses found for natural gas.
        Drake’s original well was drilled close to a known surface seepage of crude oil,
and for many years such seepages were the only reliable indicators of the presence of
oil. As demand grew, however new methods were devised for exploring the
petroleum potential of underground rock formations. There are now 3 major
exploration methods: (1) surface feature mapping, (2) seismograph observations, and
(3) Earth gravity surveys. But there is still no accurate way to predict the actual
presence of underground petroleum deposits. Exploration methods carried out on the
surface can only indicate the presence or absence of underground formations that are
favourable for petroleum accumulation.

     3.17 Выберите утверждение, соответствующее содержанию текста

1) Petroleum first formed …
   a) in metamorphic rocks.
   b) in sedimentary rocks.
   c) in igneous rocks.

2) Petroleum deposits lie at depths …
   a) from 1,500 to 7,600 metres.
   b) from 150 to 760 metres.
   c) from 150 to 7,600 metres.

3) The first well was drilled …
   a) in the 18 th century.
   b) in the 19 th century.
   c) in the 20 th century.

4) For many years the only reliable indicators of the presence of oil were …
   a) seismograph observations.
   b) Earth gravity surveys.
   c) surface seepages of crude oil.


   3.18 Подготовьте краткий пересказ текста 3D




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