EXERCISE 14 Add the missing words to this puzzle.

A crossword puzzle

Across

2. A lost item.

3. Geophysical operations performed with instrumentation and equipment on the surface and accurate recorders and tools run in the hole.

4. Type of fishing tools which used to recover lost tubing.

8. Jobs on artificial initialization of a well flow by means of gradual rise of fluid level in the well.

Down

1.Vertical pipe installed on a wellhead.

5. Porous and permeable zone in a petroleum reservoir.

6. When an item of equipment is lost in the hole, it iscalled ....

7. Light pipes used for routine operations (oil production, ESP replace­ment, pipe tripping).

CHAPTER VII

OIL PRODUCTION

EXERCISE 1 Read and translate the text "Production", using the words after the text.

Production

The production stage is the most important stage of a well's life, when the oil and gas are produced. By this time, the oil rigs and workover rigs used to drill and complete the well have moved off the wellbore, and the top is usually outfitted with a collection of valves called a "Christmas Tree". These valves regulate pressures, control flows, and allow access to the wellbore in case further completion work needs to be performed. From the outlet valve of the Christmas Tree, the flow can be connected to a distribution network of pipelines and tanks to supply the product to refineries, natural gas compressor stations, or oil export terminals.

As long as the pressure in the reservoir remains high enough, the Christmas Tree is all that is required to produce the well. If the pressure depletes and it is considered economically viable, an artificial lift method mentioned in the completions section can be employed.

Workover s are often necessary in older wells, which may need smaller diameter tubing, scale or paraffin removal, repeated acid matrix jobs, or even completing new zones of interest in a shallower reservoir. Such remedial work can be performed using workover rigs - also known as pulling units -to pull and replace tubing, or by the use of a well intervention technique called coiled tubing.

Enhanced recovery methods such as water flooding, steam flooding, or C02 flooding may be used to increase reservoir pressure and provide a "sweep" effect to push hydrocarbons out of the reservoir. Such methods require the use of injection wells, and are used when facing problems with reservoir pressure depletion, high oil viscosity, or can even be employed early in a field's life; in certain cases - depending on the reservoir's geomechanics -reservoir engineers may determine that ultimate recoverable oil may be increased by applying a waterflooding strategy early in the field's development rather than later. The application of such enhanced recovery techniques is often termed as " tertiary recovery" in the industry.

Abandonment

Finally, when the well no longer produces or produces so poorly that it is a liability to its owner, it is abandoned. In this simple process, tubing is removed from the well and sections of well-bore are filled with cement as to isolate the flow path between gas and water zones from each other as well as the surface. Completely filling the well-bore with concrete is unnecessary and cost prohibitive.

The words to be memorized:

Abandonment – закрытие, ликвидация скважины

acid matrix jobs – кислотная обработка

enhanced recovery – повышенная норма добычи

flow path – путь движения флюидов в породе

injection well – нагнетательная скважина

liability – обязательство, пассив

oil viscosity – вязкость нефти

production – выработка, добыча

pulling unit – подъемная установка для капитального ремонта скважин

recoverable oil – промышленные запасы нефти, нефтеотдача пласта

refinery – нефтеперерабатывающий завод

remedial – ремонтный

scale – твердый осадок на стенах трубопровода

shallower reservoir – коллектор на небольших глубинах

steam flooding – нагнетание паром

tertiary recovery – третичное извлечение

waterflooding – заводнение (нефтяного месторождения)

workovers – капитальный ремонт скважины

workover rig – установка для капитального ремонта скважины

EXERCISE 2 Read and translate the text "Artificial lift", using the words after the text.

ARTIFICIAL LIFT

When pressures in the oil reservoir have fallen to the point where a well will not produce by natural energy, some method of artificial lift must be used.

Used for this purpose are downhole pumps, which are divided into three general groups: pumps at the bottom of the hole run by a string of rods, pumps at the bottom of the hole run by high-pressure liquids, bottom-hole centrifugal pumps. Another method of artificial lift uses high-pressure gas to lift the oil from the reservoir.

The pumping unit is a complete set of surface equipment necessary to impart an up-and-down motion to the sucker-rod string, to which the bottom-hole pump is con­nected.

Speed reduction between the prime mover and the pitman crank is accomplished by a combination of a V-belt drive and gear reducer. With an engine of 600 revolutions per minute (RPM), a speed reduction ratio of 30 to 1 is necessary to operate the unit at 20 strokes per minute. The crank is rotated by the slow-speed shaft of the speed reducer. With one end of the pitman connected to the crank and the other end to the walking beam, the rotation is changed to the up-and-down motion of the walking beam necessary to operate the pump.

A set of weights, attached to the crank or to one end of the walking beam, coun­terbalances the weight of the rods and part of the weight of the fluid, which are suspend­ed from the opposite end of the walking beam and helps the power plant lift rods and fluid on the upstroke. The rod string is lifted by means of a cable looped over the horsehead and connected to the carrier bar to support the polished-rod clamp.

Pumping wells need a means of sealing off the pressure inside the tubing to prevent leakage of liquid and gas outside the polished rod. Stuffing boxes consist of flexible mate­rial or packing housed in a box, which provides a method of compressing the packing. The stuffing-box packing is replaced when it becomes worn.

The words to be memorized:

1. Beam pump – станок-качалка

2. Maintenance – техническое обслуживание

3. Thermal processes – тепловые процессы

4. Down hole pump – глубинный насос

5. Sucker-rod pump – штанговый насос

6. Water injection – закачка, нагнетание воды

7. Bubble point– точка начала высвобождения газа

8. Gas-to-liquid ratio– коэффициент содержания газа в жидкости

9. Pump intake – всасывающее отверстие насоса

10. Slippage – переходная зона

11. Oil reservoir – коллектор нефти

12. Bottom-hole centrifugal pumps–глубинные центробежные насосы

13. The prime mover – первичный двигатель

14. The pitman crank– рычаг соединительной тяги

15. Underground formations – подземные формации

16. Oil-producing operations- нефтедобывающие операции

17. Producing formation – продуктивный пласт

EXERCISE 3 Answer questions about the text.

1. When must methods of artificial lift be used?

2. What groups are downhole pumps divided into?

3. What does the pumping unit consist of?

4. What must be done to prevent leakage of liquid and gas outside the polished rod?

5. What provides a method of compressing the packing?