Words to be Learnt. air core drilling-воздушное колонковое бурение

air core drilling -воздушное колонковое бурение

hardened - твердый

blade -лезвие

to bore - бурить

bit head - головка долота

rod - штанга

hollow - полый

inner - внутренний

outer - внешний

barrel -бочка, цилиндр, колонковая труба

drill cuttings - буровой шлам

by injection - впрыскиванием

compressed air - сжатый воздух

chunk -патрон, планшайба

via - через

to clog -закупоривать, засорять

regolith - реголит

Exercise 6.6. Find English equivalents in the text:

1. твердые стальные и вольфрамовые лезвия

2. расположенные вокруг

3. полые штанги

4. внутренняя труба

5. головка долота

6. через полый внутренний стержень

7. воздушное колонковое бурение

8. проникать в свежие породы

9. достигать глубины

10. буровая колонна

Exercise 6.7. Make up the sentence with each word:

by injection, barrel, compressed air, drill cuttings, via, chunk, blade, to clog, bit head, to bore.

Exercise 6.8. Read and translate the text. Answer the questions on the text:

1. What is the cable tool rig traditionally used for?
2. How is it usually called yet?
3. What does the drill string consist of?
4. Why is a bailer often lowered to the borehole?
5. What is a bailer?
6. Cable tool rigs are more complex and expensive than similarly rotary rigs, aren’t they?
7. What is the depth of the world record Cable Tool Well in New York?
8. Why is there no limitation on depth for the cable tool drilling?

TEXT C: «CABLE TOOL DRILLING.»

Cable tool rigs are a traditional way of drilling water wells internationally and in the United States. The majority of large diameter water supply wells, especially deep wells completed in bed rock aquifers, were completed using this drilling method. Although this drilling method has largely been supplanted in recent years by other, faster drilling techniques, it is still the most practicable drilling method for large diameter, deep bedrock wells, and in widespread use for small rural water supply wells.

Also sometimes called "spudders", these rigs raise and drop a drill string to finely pulverize the subsurface materials. The drill string is comprised of the upper drill rods, a set of "jars" (inter-locking "sliders" that help transmit additional energy to the drill bit and assist in removing the bit if it is stuck) and a drill bit. During the drilling process, the drill string is periodically removed from the borehole and a bailer is lowered to collect the drill cuttings (rock fragments, soil, etc.). The bailer is a bucket-like tool with a trapdoor in the base. If the borehole is dry, water is added so that the drill cuttings will flow into the bailer. When lifted, the bailer closes and the cuttings are then raised and removed. Since the drill string must be raised and lowered to advance the boring, casing (larger diameter outer piping) is typically used to hold back upper soil materials and stabilize the borehole.

Cable tool rigs are simpler and cheaper than similarly sized rotary rigs, although loud and very slow to operate. The world record Cable Tool Well was drilled in New York to a depth of almost 12,000 feet. The common Bucyrus Erie 22 can drill down to about 1,100 feet. Since cable tool drilling does not use air to eject the drilling chips like a rotary, instead using a cable strung bailer, technically there is no limitation on depth.