2. Give the translation of the sentences:

1. Lightness and strength are essential in the construction of engines.

2. Today’s engines are essentially different from yesterday’s.

3. This material is readily combustible.

4. A gas is readily compressible.

5. The higher pressure ratio and temperature can also be assumed to have resulted in an improvement in specific fuel consumption.

6. The results are likely to be known in two months.

7. The investigation is likely to to give good results.

8. Tar sands contain immobile oil, which does not flow into a well bore.

9. Crude oil vary greatly in their chemical compositions.

3. Translate the words and word combinations:

Essence-essential-essentially

To essence of the paper, essential difference, to differ essentially, to increase the speed essentially, to be similar in essence.

Previous-previously

The previous chapter, the device had been used previously, it was previously stated, as previously mentioned.

Necessary- necessity

Necessary information, necessary equipment, the necessity of lubrication, the necessity of an air cleaner, it is necessary to say that.

4. Make the following sentences negative and put into the interrogative form.

1) Tar sands contain immobile oil.

2) The widely used American Petroleum Institute gravity scale is based on pure water.

3) Crude oils vary greatly in their chemical composition.

4) It is impossible to refer to a common boiling point for crude oil.

5. Find all the sentences containing modal verbs “must”, “can”. Copy them in your copy-books and translate.

6. Give the three forms of these verbs:

Vary-

Become-

Have-

Contain-

Know-

Use-

Come in-

7.. Prepare the report about the properties of oil.

Unit 3. Origin of crude oil

carbon	углерод
hydrogen	водород
primordial	изначальный, искомый
To derive	производить, получать
Single-celled	одноклеточный
diatom	диатома (вид водорослей)
algae	морская водоросль
burial	захоронение
abundant	изобильный, достаточный
Fine-grained	тонко-волокнистый
sediment	осадок
immature	незрелый
matter	вещество
to convert	превращать
insoluble	нерастворимый
detritus	обломки горных пород
decomposition	разложение
precursors	предвестник
sulfur	сульфат
nitrogen	азот

3.1 From planktonic remains to kerosene

Although it is recognized that the original source of carbon and hydrogen was in the materials that made up the primordial Earth, it is generally accepted that these two elements have had to pass through an organic phase to be combined into the varied complex molecules recognized as crude oil. The organic material that is the source of most oil has probably been derived from single-celled planktonic (free-floating) plants, such as diatoms and blue-green algae, and single-celled planktonic animals, such as foraminifera, which live in aquatic environments of marine, brackish, or fresh water. Such simple organisms are known to have been abundant long before the Paleozoic Era, which began some 540,000,000 years ago.

Rapid burial of the remains of the single-celled planktonic plants and animals within fine-grained sediments effectively preserved them. This provided the organic materials, the so-called protopetroleum, for later diagenesis (i.e., the series of processes involving biological, chemical, and physical changes) into true petroleum.

The first, or immature, stage of petroleum formation is dominated by biological activity and chemical rearrangement, which convert organic matter to kerosene. This dark-coloured, insoluble product of bacterially altered plant and animal detritus is the source of most hydrocarbons generated in the later stages. During the first stage, biogenic methane is the only hydrocarbon generated in commercial quantities. The production of biogenic methane gas is part of the process of decomposition of organic matter carried out by anaerobic microorganisms (those capable of living in the absence of free oxygen).