Petroleum

As we know from ancient manuscripts man first began to apply petroleum already some centuries B.C. Ancient people knew different properties of oil and used it for various purposes. They caulked their ships and boats with oil and made their cloths waterproof. They used petroleum as a cheap and efficient lubricant. Ancients discovered curing properties of oil and used it in medical treatment of some diseases. Besides, they utilized petroleum for the illumination of their dwellings and even as the incendiaries in frequent war battles. Since such applications didn’t require large amounts of oil ancient people managed with oil they got from the surface seeps.

Only since 19 century A.D. people have begun to use petroleum as one of the most important sources of energy. The commercial production of this valuable fuel has led to the development of modern petroleum industry.

Petroleum or as we often call it oil is a combustible oily liquid which occurs in sedimentary rocks of the Earth’s crust. Petroleum usually forms and accumulates in geological traps at the depths of 1,200 –2,000 m and deeper. Very often petroleum engineers drill deeper wells (up to 6,000 m). The deepest wells that are not so numerous reach gigantic depths of 10,000 and even more metres.

Petroleum is a liquid which consists of different hydrocarbons, i.e. compounds of carbon and hydrogen. Besides, oil often contains smaller amounts of sulphur, nitrogen and oxygen. Petroleum is a substance with a characteristic smell. The odour of petroleum depends on the nature, composition and quantity of hydrocarbons and different impurities. The colour of oil varies from light brown to dark brown, nearly black. Specific gravity of oil determines its colour. The heavier the oil the darker is the colour. Oil is much lighter than water. It doesn’t dissolve in water and forms a thin rainbow film on its surface. For oil doesn’t conduct electricity, people use some of its products in manufacturing of insulators. All sorts of petroleum are combustible. At present, petroleum is the most important fuel and energy source because of its high calorific value.

The geological science has not yet given a clear explanation for the petroleum formation. Most scientists, however, admit the organic origin of petroleum. They believe that carbon and hydrogen, i.e. the chemical basis of any oil, came from sea and land plants and animals as a result of their decomposition. In a very calm, shallow sea, dead plants and animals fell to the bottom. The accumulation of thick layers of silt above the organic matter led to an increase in temperature and rise in pressure – conditions under which liquid and gaseous hydrocarbons formed. As petroleum is a mixture of fluids, both liquid and gaseous, it often migrated far from the place where it originated.

Notes

B.C. ‘bi: ‘si: = Before Christ bi`f : `kraist – до нашей эры

A.D. `ei `di: = Anno Domini ` nou `d minai – нашей эра

i. e. `ai `i: = that is ` t is – то есть

19. Ответьте на следующие вопросы:

1.When did man first begin to apply petroleum? 2. How did ancient people use petroleum? 3. What factor has led to the development of modern petroleum industry? 4. How can one define petroleum? 5. Where does petroleum form and accumulate?
6. Does petroleum consist of different hydrocarbons? 7. What impurities does petroleum often contain? 8. On what factors does the odour of petroleum depend?
9. Is the colour of oil always dark brown? 10. What determines its colour? 11. What is the dependence of the colour of oil on its specific gravity? 12. Are all sorts of petroleum combustible? 13. Is there a clear explanation for the petroleum formation? 14. Do all scientists admit the organic origin of petroleum?

Перескажите текст, используя вопросы упражнения 19.

21. Запомните следующие слова:

oily – маслянистый remote – отдаленный

liquid – жидкость distinctive – отличительный, характерный

exclusively – исключительно to consider – считать, полагать

odour – запах molecular weight – молекулярный вес

to dissolve – растворять epoch – эпоха