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Structural Design And Mechanism Study On Water-saving Rotary Percussive Devices

Posted on:2008-07-21Degree:DoctorType:Dissertation
Country:ChinaCandidate:C H LuFull Text:PDF
GTID:1100360215471418Subject:Geological Engineering
Abstract/Summary:PDF Full Text Request
Water is one of vital resource for human survive and development, which is indispensable and irreplaceable. China is a state of water serious shortage, and was listed at 13 water deficit counties by United Nations. Water deficiency is very serious in many areas of northwest of China, even there is no water to drink for human and domestic animals in some areas, water shortage has become major factor that prevents economic development. Protecting and saving water resource is an urgent mission that China government confronted with.A large amount of water will be consumed for discharge cuttings and cool drilling tools when drilling with traditional technology, especially drill in thirsty formations. In recent years, with execution of geological survey strategy and resuscitation of geology industry of China, work capacity of drilling increases greatly, especially, a large quantity of drilling work should be completed in the course of development of western regions. When drill in draughty water scarce areas, it is often happen that one drilling machine equipped with two water tanks for carry water from faraway places, also it is often happen that operators stop work wait for water. Not only drilling efficiency will be reduced greatly, but also drilling cost will be raised by big percentages. According to introduce of fellow trade, drill a 200 to 300 meters slim hole, only the cost of carrying water can reach RMB 150 thousands, even in some water-scarce areas, drilling mission can't be accomplished at all adopting traditional drilling technology due to bad communication conditions and so on. If we can take water- saving drilling technology when drill in these water-scare areas, apparently, a large amount of surface water will be saved, and drilling cost will be reduced greatly, also the problem of engineering water shortage will be released.Rotary percussion drilling is a kind of drilling technology that overprints high frequency and low energy pulses load on rotary drilling hard-melt alloy bits or diamond bits, it is different from traditional percussion rotary drilling technology and need not use special percussion bit, it is a type of efficient, high quality, low cost drilling method, notable results can be achieved when drill with the methodespecially in mid-hard formations. Moreover, when drill with water-saving rotary percussion device, drilling efficiency would be improved highly, a large amount of surface water would be saved, drilling cost would be reduced greatly, and it opens a new technique innovative idea. Under the innovative idea, the main goal of the paper is to develop a set of water-saving, quick, safe rotary percussion self-contained drilling tools and technique used in water-scare areas. Designed rotary percussion drilling tools include pneumatic steel ball percussion device be used see before formation water and water-saving hydraulic percussion device be used see after formation water.The topic of dissertation discussed was put forward under the background of nation strongly advocated saving society and the implementation of the strategy for national geological survey, which is in urgent and front need, and also is an innovative technology. Promoted application of the technology can release to a large extent the problem of "engineering" water resource shortage, it is concrete embodiment that our major in respond to the Party Central Committee's call of establish "saving", "environmental protection", and "innovative" society.The paper is divided seven chapter, main study contents of each chapter are as follows:The first chapter in detail elaborates topic origin, research goal, significance and domestic and foreign research present situation, also main research contents and technical route that research used are introduced.The second chapter begins with analyzing the similarities, differences and applicability between rotary percussion drilling and traditional percussion rotary drilling, in connection with the actual situation of drill mid-hard rocks encountered in implementation of the strategy for state geological urvey, put emphasis on the great significance of rotary percussion drilling. Carry out detail study on mechanism of rotary percussion drilling, includes mechanical properties of rocks under dynamic load, action of impacting force on rotary cutter, generation and transmission characteristics of impact stress wave, then summarized essence and characteristics of percussion rotary drilling by which. Finally, leaded out and gave an outline of the two kinds of water-saving percussion device that designed and studied in the paper.The third chapter carries out a detailed analysis on structures of critical pieces that compos system of water-saving hydraulic percussion device at first, then elaborates on the principle of water-saving hydraulic percussion device. Finally, the structure and working principle of steel ball percussion device were analyzed detailedly.The forth chapter goes into designed theory of percussion devices, and based on which puts forward determining basis of main performance parameters, includes determining basis of percussion energy, determining basis of blow frequency, determining basis of impact velocity and transfer efficiency of percussion energy, lays a theoretical foundation for the design of water-saving hydraulic percussion device and steel ball percussion device. Design goal, principle, train of thought and design steps of system of water-saving hydraulic percussion device are put forward according to the final goal of the thesis. Primary structures, performance parameters and critical components of the water-saving hydraulic percussion are detailed designed and calculated. The anvil of critical component of steel ball percussion device and lower clutch that mainly used to transfer torque was detailed designed in the chapter.The fifth chapter summarizes purpose, importance and necessity of experimental investigation upon water-saving hydraulic percussion device and steel ball percussion device, also introduces in detail technical methods of test pump pressure and displacement of block stamp of water-saving hydraulic percussion system, then draws some correlation curves and analyses it. Blow frequency and impact velocity are worked out based on displacement curve. Approximate percussion energy was figured out utilizes Fourier series according to single period of displacement curve, flow of water-saving hydraulic percussion device with differ diameters were tested, and analyzed the causes that actual flow large than tested flow. Field tests on the water-saving hydraulic percussion were introduced overall, the problems occurred in the tests were exploded profoundly, and set forth solutions, finally, draws the conclusion that a large amount of surface water will be saved, drilling cost will be reduced greatly and drilling efficiency will be enhanced. Analyzed blow frequency is one of the most important feature parameters that decide drilling efficiency of steel ball percussion device, and blow frequency depends on pressure and flow of compressed air, so it is very important to define relation between blow frequency and pressure, flow of compressed air. How to establish function of blow frequency and pressure, flow of compressed air using dual linear regression analysis of mathematical statistics was introduced. Bench tests were Carried out on steel ball percussion device, and major parameters in working process were recorded, then draw the test results that drilling efficiency would be raised greatly drill with steel ball percussion device. Function of blow frequency and pressure, flow of compressed air was set up. Compared experimental data with data calculated according to the function, and draw the conclusion that experimental data is very close to calculated data.The sixth chapter elaborates the importance of improve design and perfect achievement on the basis of analyzing main matters occurred in tests, and put forward schemes and conceptions of improve design, Also the matters and it remove measures possibly occurred in the tests were summarized.The seventh chapter is conclusions and prospects, sums up the innovative ideas and research findings of the paper, puts emphasis on the new drilling tools and new technology of water-saving rotary percussion drilling, which has important environmental value, convenient, and easy to be popularized, at the same time, imperfections existed in study process of the paper were pointed out, and some suggestions were offered for further research.Taking a general view of the paper, major innovative ideas and returns are as follows:The main innovative ideas are as follows:1. The paper put forward the new idea that combine water-saving drilling with rotary percussion drilling creatively according to the present situation of water resource lack seriously and the background of implementation of state geological survey strategy.2. The working principle of new designed system of water-saving hydraulic percussion device completely different from traditional hydraulic percussion device, the system can carry out rotary percussion drilling on the condition that no surface water be consumed, and achieve the purposes that saving surface water, cutting cost and improving drilling efficiency.3. The design conception of steel ball percussion device is very novel, the percussion device is durable, with a simple structure, at the same time drilling efficiency would be improved highly and drilling cost would be reduced greatly when drill with the steel ball percussion device.The main returns are as follows:1. A set of water-saving, quick and safe rotary percussion self-contained drilling tools and drilling technique used in drought water scarce areas were developed under the new idea combine water-saving drilling with rotary percussion drilling, which includes pneumatic steel ball percussion device used see before formation water and water-saving hydraulic percussion device used see after formation water. 2. The major structures, critical components and performance parameters of steel ball percussion device and hydraulic percussion device were designed and calculated on the basis of study on rock broken mechanism of rotary percussion drilling, which make it is more scientific and reasonable of design of the two percussion devices.3. The important performance parameters of steel ball percussion device and hydraulic percussion device were studied on bench tests, which can provide reliable references for study and improve design of percussion devices and enhance performance of percussion devices. The mathematic model (experience equation) of blow frequency one of the most important performance parameters between pressure, flow of compressed air was established according to dual linear regression analysis of mathematic statistics based on data tested in experimental investigations.4. The author put a lot of energy on attending and organizing several field test researches on steel ball percussion device and water-saving hydraulic percussion device, the practice indicates: 10~20 times surface water would be saved, at the same time drilling efficiency would be improved highly and drilling costs would be saved greatly when drill with water-saving hydraulic percussion device. Working performance of steel ball percussion device is stable, and drilling efficiency can be enhanced highly.5. The paper summarized the achievements and lessons that author engaged in water-saving drilling technology more than 3 years, and analyzed major problems exist in research, also put forward schemes and ideas that improve design.The author prospected that scarcity of mineral resources and water resources of China could not be solved completely, so the amount of drilling work in draughty water scarce areas in northwest (even in south) of China would be more and more, we should develop new drilling methods which can save surface water. The paper is a sum of author's study on water-saving drilling technology under instruct of tutor more than 3 years, author hope it could used for reference and promote popularization and application of the new technology.
Keywords/Search Tags:Rotary percussion drilling, Water-saving drilling, Droughty water scarce areas, Percussion device
PDF Full Text Request
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