6. Define the following terms with the similar meaning in Russian.

7. Give English equivalents to the Russian words.

8. Complete the sentences using the following terminology.

1.Several types of measurements produce information on formation rock

______ _______, density, radioactivity, porosity, ______, _______, fluid saturation and permeability.

2.______ _______ invades the rock surrounding the wellbore, affects the logging of the hole and must be accounted for.

3.______ _______ measure formation radioactivity.

4._______ ________ illustrate formation porosity.

5.________ _______ evaluates formation porosity.

6.Formation resistivity is measured by ______ _______ ______.

7.The acoustic log measures the _________ of a sound wave through a rock medium.

8.Logs are obtained by lowering a _______ or tool attached to a cable or wire to the bottom of a well bore filled with ______ ____.

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9.Answer the following questions.

1.What properties of rocks are taken into consideration when measurements are made?

2.What information is produced?

3.How do geologic maps and cross-sections help you in your work?

4.What equipment is necessary to obtain logs?

5.When do you think the well is logged?

6.What affects the logging?

7.Could you name significant parameters from the center of the wellbore outward into the formation?

8.What are SP Logs used for?

9.What do resistivity logs illustrate?

10.What are radioactivity logs for?

11.Are acoustic logs important?

10.Groupwork. You are future reservoir engineers searching for commercially viable potential of oil or gas field. Discuss the way you are going to evaluate the formation.

11.Scan the text “Well stimulation”. Find the particular information:

•what stimulation is;

•techniques for well stimulation;

•definition for each type of the technique.

Well Stimulation

Sometimes once the well is fully completed, further stimulation is necessary to achieve the planned productivity. There are a number of stimulation techniques:

Acidizing

This involves the injection of chemicals to eat away at any skin damage, "cleaning up" the formation, thereby improving the flow of reservoir fluids. Acidizing is the process of injecting an acid fluid solution into a producing zone(s) for the purpose of dissolving foreign solids or rock, enlarging existing channels or creating new ones. The channels are opened or enlarged as a result of a chemical reaction. There are two basic types of acidizing:

1.matrix (low pressure) acidizing – is used on wells that have formation damage. The acids injected below the fracturing point so that the acid is allowed to work through the natural pores of the rock. This procedure is usually used on sandstone formations;

2.acid fracturing (high pressure acidizing) – uses a sufficient volume of acid under high pressure to fracture a formation, allowing the acid to penetrate further into the formation. Acid fracturing is used most often on carbonate formations (limestone and dolomite).

Fracturing

This means creating and extending a fracture from the perforation tunnels deeper into the formation increasing the surface area for formation fluids to flow into the well as well as extending past any possible damage near the wellbore. This may be done by either injecting fluids at high pressure (hydraulic fracturing), injecting fluids laced with round granular material (proppant fracturing) or using explosives to generate a high speed gas flow (propellent stimulation).

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Hydraulic fracturing is the process of injecting a special fluid, under high pressure into a producing zone to create and extend the produced fractures or high-conductive channels into a formation some distance from the wellbore. The channels are maintained with the aid of proppants or propping materials introduced during the fracturing process, after the fractures have been initiated and extended. The primary objective of this procedure is to stimulate a well to increase its productivity. Hydraulic fracturing is normally used when low permeability is a characteristic of the reservoir in general.

Hydraulic fracturing is being used more and more as a well and reservoir stimulation technique. It is used to:

1.improve the productivity of a well by creating penetrating reservoir fractures in a formation increasing its flow capacity;

2.improve the ultimate recovery from a well by extending the flow channels further into the formation;

3.aid in secondary recovery operations by improving the flow capacity in a formation near the wellbore which increases the rate of injection in disposal or pressure maintenance wells.

Perforation plays a key role in the success of hydraulic fracturing. HF has two main steps: fracture creation by application of pressure, and injection of fluid carrying proppant, which holds open the fractures to allow production. Once the fracture is created, perforations provide the entrance to the fracture for the proppant. Perforation diameter must be sufficient to prevent “bridging”, accumulation of proppant that blocks the entrance hole, preventing further treatment.

12.Groupwork. Discuss the task given above. Use the communicative formulae.

13.Pay attention to the underlined stress in the following words.

artificial effective increase reduction depletion sufficient reservoir unnecessary horizontal hydrostatic prevent exist provide mechanism dissolve

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14. Read the text “Drive Mechanisms” and do the exercises. First study the following specific term definitions to help you understand the text.

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Drive Mechanisms

The term “oil pools” refers to deposits of petroleum as though there were underground lakes of oil. A more accurate term, however, is one that is often used in the petroleum industry: oil sands.

The deposits are, in other words, more often like piles of sand or porous rock that have been saturated with oil. Oil does not really flow rapidly through sand or rock, of course, and so it must be pushed or driven. Natural flow is when the reservoir delivers fluid to the well bore. Sufficient pressure energy is needed to lift the fluid to the surface.

There are three kinds of natural drives, as the forces that push the oil are called. Each drive involves the gas and water that are almost always found with oil.

First is the dissolved-gas drive. Gas is dissolved in the oil. As it expands, it exerts the pressure which pushes the oil through rock or sand. Recovery is slow when this type of drive is encountered.

Second is the gas-cap drive. Gas has not only dissolved in the oil: a large amount of it has formed above the oil. As the gas expands, it pushes the oil through the rock or sand at a more rapid rate than when only dissolved gas is present.

Third is the water drive, in which there is a large amount of water below the oil. Pressure forces the water upward into the oil-bearing rock or sand and moves the oil ahead of it.

If none of these drives is present, the oil must be pumped to the surface. This is more expensive than when natural drives are present, since power for the pumping must be supplied.

Artificial lift – is when insufficient pressure energy exists. In this case the well may require assistance by the application of artificial lift. This provides all or portion of the vertical lift pressure losses.

Gravity drive is less common, although it’s an ideal recovery mechanism. The hydrostatic pressure on the oil column and pressure of the gas cap provide the drive to a producing well system. For this drive to be effective it requires maximum structural dip, low oil viscosity, good vertical and horizontal permeability.

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Compaction drive. The oil in the reservoir (pore space) is compressed by the weight of overlying sediments and pressure of the fluid is withdrawn from the reservoir, then the pressure depletion can be compensated by the overlying sediments compacting lower sediments. This impact creates a reduction on porosity and thus a potential compression effect.

Combination drive. The production of fluids in the majority of reservoirs is not controlled by one but often by several drive mechanisms in combination.

In the early days of the oil industry, new wells often came in as gushers. In these wells great underground pressure forced the oil upward without any control, and it was necessary to wait until it dropped enough for the oil to flow at a normal rate before any of it could be recovered. Of course, a great deal of oil wasted when a well gushed in this way.

Today, with the great increase in the price of oil – and therefore the value – great care is taken to prevent gushers. They are indeed quite rare, thanks to the use of modern technology. The petroleum industry today is very much concerned about acquiring the greatest possible amount of oil from each deposit without unnecessary waste.

Fig.6. Drive Mechanisms:

1. water drive 2. dissolved-gas drive 3. gas-cap drive

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15. Give synonyms to the following words.

17. State whether the following statements are true or false. Correct the false statements.

1.Oil does not really flow rapidly through sand or rock.

2.To lift the fluid to the surface small amount of energy is needed.

3.The forces that push the oil are called natural ones.

4.As gas expands, it exerts the pressure which pushes the oil through the reservoir.

5.Artificial lift – is when sufficient pressure energy exists.

6.For the gravity drive to be effective low structural dip is required.

7.A great deal of oil wasted when a well gushed.

8.The petroleum industry today is concerned about stopping wasteful gushers.

18. Answer the following questions.

1.The term “oil pools” refers to deposits of petroleum, doesn’t it?

2.What do deposits look like?

3.When does natural flow occur?

4.Are there two kinds of natural drives?

5.In what condition does gas occur in the oil?

6.What type of natural drive makes the recovery slow?

7.Why must oil be pumped to the surface?

8.In what wells is the pressure without control?

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19. In pairs discuss the advantages and disadvantages of drive mechanisms you know.

Express your own point of view using the following expressions:

Ex.20.  You will hear a part of a lecture on Petroleum Products.

a) For statements 1–7 complete the notes that summarize what the speaker says. You will need to write a word or a short phrase in each box.

b) Tell about petroleum products using the above given information.

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APPENDIX

USING OIL

Crude oil is a mixture of many different hydrocarbons – chemicals which contain only hydrogen and carbon atoms.

Crude oil is not much used until it is separated into more useful parts, called fractions. This is done by fractional distillation.

Most of the fractions are burnt as fuels. The rest go to make plastics, detergents and many other important chemicals.

1.What is a hydrocarbon?

2.Octane is a hydrocarbon which has eight carbon atoms. Which fraction would you find it in?

3.Which property of hydrocarbons is used to separate them?

4.Which fraction has the lowest boiling range?

5.Which fraction would be the hardest to boil?

6.Which of the fractions are burnt as fuels?

7.Which fraction do you think there is most demand for in the world?

8.What do you think would happen to the price of crude oil if:

(a)all countries banned the use of nuclear power?

(b)the Persian Gulf, through which most of the West's oil is carried, was closed by war?

9.Decide what you think might happen if the oil runs out.

10.Write a paragraph of 100-150 words explaining what you think will happen.

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Fig. 8. When the oil runs out.

(Stephen Beer, David Edwards “Thinking Through Science”, London,

1989)

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REFERENCES

1.Beer, S., Edwards, D. (1989). Thinking Through Science. London.

2.Belousov V. Oil and Gas Industry. (2004). Moscow.

3.Dictionary for the Petroleum Industry. Austin, Texas:

Schlumberger, 1997.

4.Dvoretskaya, O.B. (2006). Business English :"Titul" publishers.

5.Encyclopaedia of Geology, Vol. I–IV: Elsevier Academic.

6.Hyne, N. (1998). Dictionary of Petroleum Exploration. Drilling and production. Tulsa, Oklahoma.

7.John, F., Cook, M., Graham, M. (1999). Hydrocarbon Exploration and Production (Development in Petroleum Science 46). Amsterdam.

8.Lambert, D. (1998). The Field Guide to Geology. Cambridge

University Press.

9.North, F.K. (1985). Petroleum Geology. London.

10.Oil and Gas Production Primer. Houston, 1989.

11.Wood’s Illustrated English – Russian \ Russian-English Petroleum

Technology Dictionary. ALBION. WOODS.

12.Баракова M.Я. Английский язык для горных инженеров. – М.:

Высшая школа, 2001.

INTERNET RESOURCES

13.Material supplied by the Institute of Petroleum.

14.http.//www.science. ubc.ca\~geol202\sed\sili\arc.html

15.Wikipedia. The free encyclopedia. http://www.wikipedia.org/

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Chapter 3

DRILLING

Т.V. Vasilchenko

Т.V. Bocharova

UNIT 1

LIFE OF A WELL

An oil well is a term for any perforation through the Earth's surface designed to find and release both oil and gas hydrocarbons.

Lead-in

Life of a well can be divided up into five segments. What are they (in Russian)? List the words in English and place the blocks according to the life stages of a well:

A

D

Pr

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