Electro-discharge Technology for Drilling Wells and Concrete Destruction (eBook)

Associate Professor Vladislav F. Vajov graduated from the Tomsk Polytechnic Institute (now the Tomsk Polytechnic University (TPU)) in 1963. He subsequently received his Ph.D. and Doctor of Science degree from the same university in 1974 and 2015, respectively. His doctoral dissertation explored the technological fundamentals of electric impulse drilling and cutting of rocks. Since 1963, he has worked at the High Voltage Research Institute (now the Engineering School of New Production Technologies). Having participated in virtually all field tests of electro-discharge drilling installations over the years, he is also the author of more than 100 scientific publications and holds 29 certificates and patents. Professor Vasily Ya. Ushakov graduated from Tomsk Polytechnic University (TPU) in 1962, and received his Ph.D. and Doctor of Science degree from the same university in 1965 and 1973, respectively. Ushakov is a well-known expert on high-voltage engineering, particularly in the area of electric breakdown of condensed media, insulation of pulsed power equipment, and electro-discharge technology. He has published over 250 scientific articles, 25 monographs and textbooks, and holds 38 invention certificates and patents. From 1974 to 1981, he was head of the high-voltage department; from 1979 to 1992 he was Director of the High-Voltage Research Institute; and from 1992 to 2001 he was the Vice-Rector for Research (all at the TPU). Since 2001, he has led the TPU’s Resources Saving Centre.Candidate of Technical Sciences Nikolai T. Zinoviev graduated from the TPU in 1973 and received his Ph.D. degree in 1980. The topic of his thesis was “Investigation of the energy characteristics of the spark channel in order to optimize the devices of electro-pulse technology.” In subsequent years, he continued to work on the same problem as a senior research fellow and head of the laboratory “Physics of Electro-Impulse Processes” at the Engineering School of New Production Technologies (1984–2010). Under his leadership, full-scale installations for the demolition of sub-standard reinforced concrete products were manufactured, tested and supplied to Russian and foreign customers (Kazakhstan – 1992, Japan – 1995, Germany – 1997, and Armenia – 1998). He has published one monograph and 20 scientific articles on this topic, and holds more than 30 certificates and patents.

Preface 5
References 9
Contents 10
Abstract 14
1 Relevance, Physical Basics, and Problems of Large-Scale Introduction of Electrodischarge Technology 15
1.1 Destruction of Solid Dielectric Materials by Traditional Methods 15
1.2 Physical Basics of EDT 17
1.3 Problems of Large-Scale Implementation of EDT 23
References 25
2 Impulse Electrical Strength of Rocks and Concretes 27
2.1 Physico-Mechanical and Electro-Physical Characteristics of Rocks and Concretes and Their Influence on the Electrical Strength 27
2.1.1 Rocks 28
2.1.2 Concretes 32
2.2 Influence of the Factors Manifested Themselves in EDT on the Electrical Strength of Rocks and Concretes 36
2.2.1 Voltage Impulse Duration, Polarity, and Shape 36
2.2.2 The Interelectrode Distance and the Position of the Electrodes Relative to the Material or Article to Be Destroyed 39
2.2.3 Temperature and Static Pressure 42
2.2.4 Impact of Dynamic Loads Resulting from Preceding Discharges 46
References 51
3 Liquids Used as an Insulation and a Working Medium 53
3.1 Requirements for Liquids Used in the EDT 53
3.2 Influence of Factors Manifested Themselves in the EDT on the Electric Strength of Liquids 55
3.2.1 Voltage Impulse Duration, Polarity, and Shape 55
3.2.2 Pressure and Temperature 58
3.2.3 Interelectrode Gap 61
3.2.4 Position of the Electrodes Relative to the Liquid-Solid Interface 63
References 65
4 Discharge Channel as a “Working Tool” in EDT 66
4.1 Electrophysical Parameters and Dynamics of the Discharge Channel 67
4.1.1 Discharge Channel as an Electrical Load 68
4.1.2 Energy Characteristics of the Discharge Channel. Transient Processes 79
4.1.3 Energy Balance of the Channel Stage of the Discharge 86
4.2 Peak Pressure in the Discharge Channel 91
References 93
5 Regularities of Rock Destruction in the Process of ED-Drilling of Wells 95
5.1 Spatiotemporal Regularities of the Breakdown in Gaps Formed by Electrodes Superimposed on One Surface of a Solid 95
5.2 Geometrical Parameters of a Slabbing Crater 100
5.3 Influence of the Energy Input Dynamics on the Destruction Characteristics 106
5.4 Combined Effect of Elevated Pressures and Temperatures on the ED-Destruction of Rocks 110
References 114
6 Insulating Design in EDT Installations 116
6.1 Requirements for Insulating Materials and Structures 116
6.2 Single-Impulse and Multi-impulse Strength of Insulating Materials and Structures in EDT 118
6.2.1 Methods of Sample Preparation and Testing 118
6.2.2 Statistical Processing of Results 120
6.2.3 Multi-impulse Electrical Strength of Polyethylene Insulation 122
6.2.4 Influence of the Preliminary Exposure to Voltage Impulses on the Single-Impulse Electrical Strength of Polyethylene 124
6.2.5 Influence of the Preliminary Exposure to Voltage Impulses on the Multi-impulse Electrical Strength of Polyethylene 127
6.3 Basic Principles for Designing and Preliminary Rejection of Electroinsulating Structures 129
References 135
7 Drilling of Wells 137
7.1 Experience of ED Drilling in the Initial Stages of EDT Development 138
7.2 Technological Scheme of the Drilling Rig 141
7.3 Operational Characteristics of Drill Rigs 144
7.3.1 Geometrical Parameters of the Drill Head 144
7.3.2 Operating Voltage 155
7.3.3 Particle Size Distribution and Fractional Composition of Drill Cuttings 156
7.3.4 Intensity of Well Flushing 163
7.3.5 Productivity and Energy Consumption 165
7.3.6 Drilling Speed 171
References 175
8 Destruction and Recycling of Reinforced Concrete Products 176
8.1 Urgency of the Problem and Ways of Its Solution 176
8.2 Studies of the Characteristics of ED Concrete Destruction on Samples 178
8.2.1 Experimental Procedure 178
8.2.2 Influence of the Regime of Energy Liberation in the Discharge Channel on the Destruction Characteristics 181
8.2.3 Influence of Mechanical Strength of Concretes on the Effectiveness of Their Destruction 184
8.3 Main Technological Characteristics of the ED Destruction of Sub-standard Reinforced Concrete Products from the Results of the Laboratory Installation Testing 185
8.4 Design Principles and Basic Elements of Installations Intended for Destruction of Reinforced Concrete Products 190
8.4.1 Composition and Parameters of the Main Installation Components 190
8.4.2 High-Voltage Impulse Generator 192
8.4.3 Electrode System (Actuator) 194
8.4.4 Control of the Position of the Electrode System Relative to the Product to be Destructed 206
8.4.5 Preparatory Technological Operations 208
8.5 Performance Indicators Semi-industrial Installations 209
References 211
9 Fragmentation of the Filler—The Final Stage of Preparation of Reinforced Concrete Products for Utilization 212
9.1 Choice of the Method of Fragmentation of a Concrete Filler 212
9.1.1 Mechanical Methods of Fragmentation 213
9.1.2 Electrohydraulic (Electro explosive) Method of Fragmentation 214
9.2 Electrodischarge Method of Fragmentation of a Concrete Filler 216
9.2.1 Fragmentation Plant 217
9.2.2 Specific Energy Consumed for Fragmentation 219
9.2.3 Granulometric Characteristics of Products 222
9.2.4 Physical and Technical Characteristics of a Crushed Concrete Filler 224
9.3 Extraction of Coarse Filler from Concrete 227
9.4 Properties of Concrete with Crushed Stone Filler from Recyclable Reinforced Concrete 234
References 238
10 Breaking and Cutting of Rocks and Concretes 239
10.1 Breaking of Rocks and Concretes 239
10.1.1 Breaking with Superimposed Electrodes 241
10.1.2 Breaking Using Blast Holes 242
10.2 Cutting 244
10.2.1 Cutting with a Cyclically Movable Electrode System 244
10.2.2 Cutting with a Continuously Movable Electrode System 245
References 252
Conclusion 254
Conclusion 255
Appendix A: Photographs of Installations for RCP Destruction 255
Appendix B: Photographs of Some RCPs in Different Destruction Stages 259
Bibliography 267