1. Answer the questions

1. When may drilling be stopped?

2. What is casing intended for?

3. When may casing be used during the drilling process?

2. Find equivalents from the text

крепления меньшего диаметра

предназначено, чтобы предотвратить любое попадание

на общую глубину непрерывно

на внешнюю окружность.

3. Complete the table ( pay attention to degrees of comparision):

modern
		the deepest
	slower
	much faster
	lower
capable
		the widest

f) The turbodrill

One variation in rotary drilling employs a fluid-powered turbine at the bottom of the borehole to produce the rotary motion of the bit. Known as the turbodrill, this instrument is about nine metres long and is made up of four major parts: the upper bearing, the turbine, the lower bearing, and the drill bit. The upper bearing is attached to the drill pipe, which either does not rotate or rotates at a slow rate (6 to 8 revolutions per minute). The drill bit, meanwhile, rotates at a much faster rate (500 to 1,000 revolutions per minute) than in conventional rotary drilling. The power source for the turbodrill is the mud pump, which forces mud through the drill pipe to the turbine. The mud is diverted onto the rotors of the turbine, turning the lower bearing and the drill bit. The mud then passes through the drill bit to scour the hole and carry chips to the surface. The turbodrill is capable of very fast drilling, but the bit and bearings wear quickly in the harsh environment. Turbodrills were widely used in the former Soviet republics of Russia and Central Asia, but they are rare elsewhere.

1. Answer the questions

1. What is turbodrill?

2. What are the parts of turbodrill?

3. What part of a turbodrill rotates faster?

4. Are turbodrills used now everywhere?

2. Find equivalents from the text

состоит из четырех основных частей

быстро изнашиваются в суровых условиях

вращается в медленном режиме

Переносит осколки на поверхность g) Directional drilling

Frequently, the drilling platform and derrick cannot be located directly above the spot where the well should penetrate the formation (if, for example, petroleum reservoirs lie under lakes, towns, or harbours). In these cases, the surface equipment must be offset and the well bore drilled at an angle that will intersect the underground formation at the desired place. This is done by drilling the wells vertically to start and then angling them at depths that depend on the relative position of the target. Since the nearly inflexible drill pipe must be able to move and rotate through the entire depth, the angle of the borehole can be changed only a few degrees at any one time. In order to achieve a large deviation angle, therefore, a number of small deviations must be made. The borehole, in effect, ends up making a large arc to reach its objective. The traditional tool for “kicking off” such a well is the whipstock. This consists of an inclined plane on the bottom of the drill pipe that is oriented in the direction the well is intended to take. The drill bit is thereby forced to move off in the proper direction. A more recent technique makes use of a “bent sub” at the bottom of the drill pipe that is pointed in the desired direction. A mud-powered turbine at the bottom of the sub drills the first few metres of the angled hole. Directional drilling techniques have advanced to the point where well bores can end in horizontal sections with lengths greater than 300 metres.

1. Answer the questions

1. When is directional drilling used?

2. What does the whipstock consist of?

3. What length can in horizontal sections of well bores be?

2. Find equivalents from the text

угол наклона скважины может быть изменен

часто башенная вышка не может быть установлена непосредственно над

должна быть способна двигаться и вращаться

будет проникать сквозь подземные слои в нужное место

более современные технологии сделали возможным.

3. Complete the following words from the text:

D___ll_ng, r_t_te, adv_nt_ge, f_rm_tion, r_t_ry, techn_q___, p_n_tr_te.

4. Find all the sentences from the texts (d, e, f, g) in the Passive Voice. Copy them in your exercise-books and translate.

5. Find all the sentences from the text (g) with the modal verbs.