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Abstract

Content

Introduction

In recent years is an intensive search for solutions to improve performance perspective until recently, methods of drilling, including those related to the most high-speed method of conducting wells - drilling solid-bottom roller bits.

In this method, rock bottom destroyed rotating the bit to which the axial load and torque. Torque on the bit is transmitted from the rotator (rotor) through the column of drill pipes. Axial load is created in the main part of the weight of above chisel drill collar (HDP).

it is Known that drilling roller bits accompanied by vertical oscillations of the drill string. With a significant portion of rocks more effectively destroyed by long term stress.

A Direct dependence of the mechanical drilling speed from the impact of application of the load on the bit, as well as the likelihood of the use of energy vibrating column of drill pipes as a generator of dynamic forces transmitted on the rock cutting tool, contributed to the formulation of the problem, in accordance with which it was necessary to solve a question of designing a simple shock system, a source of food would be the energy of the drill string.

The Proposed solution may be promising in traditional drilling wells units with rotary rotator, especially in the intervals of spudding and the shallow depth of the well, when the weight of the projectile is not sufficient to create destructive efforts on the rock. In this case, using the energy of fluctuations of the drill string to create dynamic loads on the bit in conjunction with a static pressure of the emerging available weight of the drill, creates favourable conditions for more efficient rock failure.

1. Rationale topics and names, the relevance of the work

A Direct dependence of the mechanical drilling speed from the impact of application of the load on bit involves the search for solutions aimed at the use of energy vibrating column of drill pipes, which coupled with static load, the emerging weight of the drill string, can create favorable conditions for more efficient rock failure.

The Compilation and analysis of various percussion systems, suggests that in terms of working availability of, and prospects for the best option is to use a mass sliding type, freely located on the drill string and based on bit. In the basis of this idea is the idea that if the body with greater mass causes elastic body blows with a smaller mass, the last bounce off it with a speed greater than the speed of the collision. Therefore, if the kit consists of several bodies with constantly decreasing mass, saying the most serious of them any rate, we can take out of this system even greater speed.

2. Study purpose and objectives, deliverables

The Purpose of work is development and substantiation of the parameters of the shock system in the form of mass set of sliding type, which coupled with static load, the emerging weight of the drill string, creates favourable conditions for more efficient rock failure by rolling cutter bits.

Connectivity with scientific programmes and plans, execution of works on applications of scientific or industrial organizations.

The Tasks foreseen in the master's work are considered as part of the studies in accordance with the scientific direction of the Department of Technology and Technology of Drilling and related technical developments strike systems to intensify destruction of the rocks on the bottom of a well.

Research Tasks are:

  1. Analysis and generalization of literary sources for selecting the method for theoretical substantiation of the parameters of weighting compounds, used as the source of the formation of additional dynamic load on the bottom.
  2. Developing a method and calculation of the weighting in the layout of a shock site.
  3. Development of physical models of the shock system and experimental evaluation of the validity of the application weights for the selected performance impact drill string.
  4. Development of design documentation of a shock site, in the form of mass set, sliding on a smooth surface drill pipe, installed directly over the roller cutter bit.

Idea is the use of the General principles of designing the layout of a shock system for the selection of a combination of the number of masses of weighting compounds, which will achieve the maximum effect of the dynamic impact of bits on the breed.

research Object - processes and technological modes of rotary drilling wells with rock bits.

The Subject of investigation - transfer processes of dynamic loads on the bottom when you use a layout shock system, in the form of mass set situated above the roller cutter bit.

The Possible results that are expected in the performance of work, their novelty and value method and computer program for calculating the parameters of weighting compounds. Detailed documentation and example of a model of a shock to the system.

3. Overview of research and development

There are various ways to improve the performance of a roller drilling: the use of combined rock-destruction tool; new high-tech roller bits foreign firms; by using наддолотных pneumatic and гидроударников installed over roller cutter bit, allowing to reduce the cost of drilling, and therefore the need to purchase expensive imported equipment and others.

At the initial intervals drilling bit load may be insufficient. To increase drilling efficiency, you must use the UTL increased weight.

Increasing the performance of drilling wells are largely ensure the reduction of the biggest wastes of time to replace the worn out rock cutting tool through the implementation of diverse automation and mechanization.

To date among specialists no clear opinion about the role of additional dynamic impact on the working face during drilling by rolling cutter bits. Some researchers believe that the oscillatory processes in the drill string lead to the reduction of the useful life of the drilling string and bits, and, therefore, reduce the efficiency of the drilling process. Therefore, their development aimed at the creation of a shock absorbers and dampers fluctuations of the drill string. Other researchers are of the opinion about the necessity of increasing of oscillatory processes in the drill string, for which offer the use of a dynamically active layouts drill, which include vibrators, гидроударники, виброусилители etc. And they explain their calculations positive results of experimental works and field tests. Moreover, some researchers recognizes the positive role, as absorbers and pathogens oscillations under certain conditions, which led to the creation of the layout of the drilling Assembly, in which simultaneously both types of devices.

Thus, on the basis of analysis of previous research, we can conclude that the impact of additional dynamic impact on the slaughter really ambiguous. And therefore, to speak about good and harm of vibrational processes, acting upon the bottom, can only be based on the following considerations. As is known, the work of the roller bits on the bottom operates static load exerted by the weight of the compressed part of BHA, and dynamic load resulting from перекатывании milling cutters for the slaughter. Then, if the sum of static and dynamic loads will be considerably less than the permissible load on bit, then we should talk about the need to strengthen the oscillatory processes for extra impact on the bottom. In this case, such measures contribute to the intensification of the process of rock failure and increase of mechanical boring speed (usually observed in rotary drilling wells). Otherwise, when the total load on bit approaches the value of the permissible load, it is necessary to apply measures for the oscillation suppression, resulting in additional pressure on the bottom. This is because even irregularly occurring efforts at contact «bit - rock», and especially bounces bit from the face can lead to rapid deterioration of the rock cutting tool and its breakdowns.

Conclusion

Analysis of different percussion systems, made the generalization of literary information, led to the conclusion that in terms of working availability of, and prospects for the best option is to use a mass sliding type, freely located on the drill string and based on bit. In the basis of this idea is the idea that if the body with greater mass causes elastic body blows with a smaller mass, the last bounce off it with a speed greater than the speed of the collision.[1]

References

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