Guseva Galina Institute of Mining and Geology Speciality: Technics and technology of investigation of deposits of minerals Theme of master's work: Development of a design eviction tap to eliminate accidents at breakage of drill pipes Scientific adviser: Pettik U.V.

Introduction

The device designed is a repair tool, which is used for breakdown elimination by the drilling of mine shafts and holes with the big diameter. Substantiation of Topic and Title. Topicality of the project

A lot of breakdowns may occur in the process of drilling and operating, and also during the borehole repairs. Wide range of devices, called the fishing tools, is used for breakdown elimination.

One of the most reliable instruments for breakdown elimination is fishing tap. The main disadvantage of a tap is its disability to slacken. On the other hand, it is rated at the small pipe diameter and single use during tripping-in.

The goal of the project: The design of the structure of the slackening mechanical tap with a rifled claw for catching of ragged drilling pipes ended with joint box or lock on the top.

Research tasks:

1. The design of the constructive scheme of a slackening mechanical tap (the analysis of the arranging solutions).
2. Study of the rational constructive parameters of the optimal mechanical tap construction.
3. Implementation of the development works.
4. Design of the preparation technology for the mechanical tap for operating and implementation of fishing operations.

The idea of the work is to increase the efficiency of breakdown operations on dismantling of drilling pipes breaks in the deep, by means of slackening mechanical taps.

Object and Subject of the Research

Object of the research - is engineering means and technology of drilling pipes breakdown elimination.

Subject of the research - is construction and parameters of the tap that ensure its slackening in case of impossibility of broken drilling pipes lifting.

Possible Results

1. Explanation of operation principles for slackening mechanical tap with the possibility of the regripping without its preliminary lifting to the surface.
2. Design of the new construction of the slackening mechanical tap.
3. Development of the new slackening operation technology on elimination of the drilling string breakdown.

Operation Principle

Assembled tap-gauge is lowered to a borehole on drilling pipes. Before getting to upper ending of the drilling string, the lowering is slowed down and, if needed, a washing pump for the upper ending of retrieved drilling string is engaged. Then, the end of a tap-gauge is put into a coupling; and by left rotation of its screw-thread die a threading is made in a coupling while a tap-gauge is unscrewed from a coupling of pipes, that are pulled out.

After that, the drilling string is pulled out as a whole or in parts.

The disadvantage of a tap is the necessity of its lifting by the feeble claw attempt.

Estimated Novelty

The change in the construction of a tap is necessary for elimination of the mentioned disadvantage and for the possibility of the repeating captures. For this, reach-through hole of a tap is joined with a blind hole for pawls "6" on the side opposite to a spring with the help of canals. When the washing liquid is given under the pressure into a reach-through hole of a tap, under the influence of the radial power, pawls "6" compress a string "7" and sink. Screw-thread dies release and return to the last lower or upper position, depending on the tap operation phase. At the same time, screw-thread dies "2" are fastened with the help of pawls "6".

Planned Practical Results

For realization of the given operation principle the following is necessary: two holes on the inside surface along a parallel long axis of a screw-thread die; and renunciation of adjusting screw "8".

Conclusion

After consideration and deep analysis of the problems that arise in the process of breakdown elimination, the following conclusion is made: the suggested device is more effective and economical than those used previously, because there is no need to lift the device to the surface after the feeble attempt of the capture. This reduces expenditure of time of the breakdown elimination and also reduces extra costs.

It is assumed, that the adoption of the suggested device will ensure the high effectiveness of the breakdown elimination.

Selected Bibliography

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2. Шерстнев Н.М., Расидзе Я.М., Ширинзаде С.А. Предупреждение и ликвидация осложнений в бурении. – М.: Недра, 1979. – 224с.
3. Самотой А.К., Джафаров А.А.-Д. Ловильный инструмент. Справочное пособие. М.: Недра, 1985. – 156с.
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8. Пустовойтенко И.П. Предупреждение и ликвидация аварий в бурении. - [з-е издание, переработанное и дополненное] / И.П. Пустовойтенко. – М.: Недра, 1988 – 278с.
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10. Ликвидация аварий (сборник)