Boliden’s Garpenberg mine produces Zn-Pb-Ag(Cu-Au) using a sublevel stoping with pastefill mining method. The orebody is strongly affected by the existence of weakness zones mainly consisting of Talc Schist and Phlogopite Schist which affect the design, planning and production of the stope. To mine the ore two drifts, one below and one above the ore section, are excavated typically at a distance of 25 meters. Afterwards parallell longhole drilling is done for the primary stopes and drilling in a fan pattern is done for secondary stopes by automated remotely controlled SIMBA drills. Those drill rigs are equipped with sensors that record drilling parameters during drilling, so called Measurements While Drilling. The drilling parameters that are recorded are depth, time, penetration rate, percussive pressure, feed pressure, dampening pressure, rotation pressure and flush pressure at selected intervals. This thesis aims to identify the mentioned weakness zones using the existing MWD data. First of all, this thesis contains six chapters. The first is a detailed introduction to the problem. The second chapter describes the geology, the mining method used in Garpenberg and also includes a brief section on how SIMBA drills work. The third chapter consists of the MWD theory, literature review and the methodology used to come up with the solution of the stated problem. In the fourth chapter is described how a successful method was developed using 3D models created from MWD data and geologic maps to identify the weakness zones and classify the rock based on four filters created. The fifth chapter is a detailed discussion of the results and findings of this thesis. Finally, the sixth chapter is the conclusion.

Drilling and blasting procedures are a critical part of mine planning activities and improvements in this stage can lead to better productivity downstream and lower costs. One potential improvement would be better understanding the characteristics of the rock for blast design purposes. The distribution of material properties within a rock mass is very unpredictable so to more accurately determine its characteristics a controlled drilling environment is needed. Many mines possess the capacity to record Measurement While Drilling (MWD) data but don't utilize it. This project investigates and analyzes MWD data from an anonymous iron ore mine. Machine learning was used to analyze the MWD data for the sake of improving blast optimization and productivity and has been used to successfully implement MWD data in other studies. Based on previous work, it has been demonstrated that the utilization of MWD data can assist with developing a better understanding of rock mass properties and other variables of importance during the drill, blast, and mine planning processes. This report investigates using MWD data to classify and predict lithology and utilize regression modeling to identify potential soft spots within blast patterns for blast optimization. The MWD data of six blast patterns from an anonymous mine underwent data processing and then were modeled. The lithology was able to be approximately classified with new information of potentially revealed bed boundaries and blast pattern soft spots. / Master of Science / In the mining industry, liberating ore from the ground is necessary to process the material and generate products. To accomplish this liberation objective a process of drilling and blasting is utilized. A pattern is designed, and holes are drilled that match the spacing and depth of the design. The blast holes are loaded with explosives and detonated to create fractured rock for the liberation of desired material. During the drilling process, drilling parameters are recorded called Measure While Drilling (MWD) data. Previous research has demonstrated that modeling techniques using MWD data can assist with developing a better understanding of rock mass properties and other variables of importance during the drill, blast, and mine planning processes. Utilizing MWD data and machine learning to improve blasting procedures by classifying and predicting bed assignment and potential soft spots in a blast hole will be investigated in this research. The MWD data comes from 6 blast patterns from an anonymous iron ore mine. After the data was processed and modeled the lithology was classified with a validation accuracy of approximately 78% and potential soft spots estimated.

Rock blasting is one of the most dominating operations in open pit mining efficiency. As many downstream processes depend on the blast-induced fragmentation, an optimized blasting strategy can influence the total revenue of a mine to a large extent.Boliden Aitik mine in northern Sweden is one of the largest copper mines in Europe. The annual production of the mine is expected to reach 36 million tonnes of ore in 2014; so continuous efforts are being made to boost the production. Highly automated equipment and new processing plant, in addition to new crushers, have sufficient capacity to reach the production goals; the current obstacle in the process of production increase is a bottleneck in crushers caused by oversize boulders. Boulders require extra efforts for secondary blasting or hammer breakage and if entered the crushers, they cause downtimes. Therefore a more evenly distributed fragmentation with less oversize material can be advantageous. Furthermore, a better fragmentation can cause a reduction in energy costs by demanding less amounts of crushing energy.In order to achieve a more favorable fragmentation, two alternative blast designs in addition to a reference design were tested and the results were evaluated and compared to the current design in Aitik. A comparatively large bench was divided to three sections with three different drill plans, which led to different specific charges in each section. The sections were drilled in patterns of 6x9 m, 7x9 m and 7x10 m of burden and spacing; planned specific charges of the sections were 1.17 kg/m3, 1.02 kg/m3, and 0.91 kg/m3 respectively. Similar to the current drill plan in Aitik, the section with 7x9 m (1.02 kg/m3 specific charge) was used as the reference for results comparison. The drilling and charging processes were monitored carefully and the post-blast parameters were measured accordingly. Laser scanning was used to measure the swelling of the sections and two different methods of image analysis were utilized to evaluate the fragmentation of the rock for each section. Drilling log data (MWD) were analyzed to evaluate the hardness of the rock; energy consumption log of the crusher was also analyzed and all the data was collected in a single database. VBA (Visual Basic for Applications) programming language was embedded within data spreadsheets to correlate the mentioned data to the coordinates of the rock by means of Minestar logs, which include both timestamps and coordinates of all machinery e.g. shovels and trucks.The results of the test show significant improvements in fragmentation and oversize material percentage in the section with 6x9 m drill plan (1.17 kg/m3). The advantage of 6x9 m plan was confirmed by 52% higher swelling, 66% lower oversize material and 26% lower crushing energy compared to the reference section. The section with 7x10 m drill plan (0.91 kg/m3) also showed theoretically acceptable results; however, the deviations from reference were not as large as formerly mentioned section. The swelling had a decrease of 8% compared to the reference section and the percentage of oversize material and crushing energy were increased by 16% and 2% respectively.Presented results are based only on technical aspects and do not include the costs of drilling and charging. Thus, in order to evaluate the drill plans in practice an economical evaluation of the sections should be conducted. Also a confirmation test with more accurate geology explorations is recommended.Finally, upon the request of Boliden Mines, a short report on the usage of Air-decking technique in Aitik is enclosed as an appendix. The report includes a brief introduction to air-decking and discusses practical solutions to apply this technique in Aitik. / Validerat; 20121001 (anonymous)

Prior to an underground excavation a site investigation is carried out. This includes reviewing and analysing existing data, field data collected through outcrop mapping, drill core logging and geophysical investigations. These data sources are combined and used to characterise, quantify and classify the rock mass for the tunnel design process and excavation method selection. Despite the best approaches used in a site investigation, it cannot reveal the required level of detail. Such gaps in information might become significant during the actual construction stage. This can lead to; for example, over-break due to unfavourable geological conditions. Even more so, an underestimation of the rock mass properties can lead to unplanned stoppages and tunnel rehabilitation. On-the-other-hand, the excavation method itself, in this case, drill and blast, can also cause severe damage to the rock mass. This can result in over-break and reduction of the strength and quality of the remaining rock mass. Both of these attributes pose risks for the tunnel during excavation and after project delivery. Blast damage encompasses over-break and the Excavation Damage Zone (EDZ). In the latter irreversible changes occur within the remaining rock mass inside this zone, which are physically manifested as blast fractures. In this thesis, a number of methods to determine blast damage have been investigated in two ramp tunnels of the Stockholm bypass. Herein, a comparison between the most common methods for blast damage investigation employed nowadays is performed. This comparison can be used to select the most suitable methods for blast damage investigation in tunnelling, based on the environment and the available resources. In this thesis Ground Penetrating Radar, core logging (for fractures) and P-wave velocity measurements were applied to determine the extent of the blast damage. Furthermore, the study of the two tunnels in the Stockholm bypass shows a significant overestimation of the actual rock mass quality during the site investigation. In order to gain a more accurate picture of the rock mass quality, Measurement While Drilling (MWD) technology was applied. The technology was investigated for rock mass quality prediction, quantifying the extent of blast damage, as well as to investigate the potential to forecast the required rock support. MWD data was collected from both grout and blast holes. These data sets were used to determine rock quality indices e.g. Fracture Indication and Hardness Indicator calculated by the MWD parameters. The Fracture Index was then compared with the installed rock support at the measurement location. Lastly, the extent of the damage is investigated by evaluating if the MWD parameters could forecast the extent of the EDZ. The study clearly shows the capability of MWD data to predict the rock mass characteristics, e.g. fractures and other zones of weakness. This study demonstrated that there is a correlation between the Fracture Index (MWD) and the Q-value, a parameter widely used to determine the required rock support. The study also shows a correlation between the extent of the blast damage zone, MWD data, design and excavation parameters (for example tunnel cross section and charge concentration).

No description available.

For developing the available hydrocarbon reserves and for exploring new reservoirs, deeper and more complex wells are drilled. Drilling such deeper and complex wells requires a constant monitoring and controlling of the well paths. Therefore, the bottom hole assembly, the lower section of the drill string above the drill bit, is equipped with numerous measuring sensors for collecting geological and directional data while drilling. The collected data have to be transmitted to the surface in real time. Prior to transmit the data measured downhole to the surface, they are processed and translated into a binary code. Accordingly, the data will be represented as a series of zeroes and ones. The most common method for data transmission in boreholes is the so called mud pulse telemetry which sends the information through the drilling mud inside the drill string by means of coded pressure pulses. There are two types of devices available for downhole pressure pulses generation. The first type is the (positive or negative) pressure pulser which transmits the data by quasi-static variations of the pressure level inside the drill string. The second type is the (rotating or oscillating) mud siren which transmits the data by generating continuous pressure waves at specific frequencies. The main disadvantage of the mud pulse telemetry is its low data transmission rate which is about 10 bps. This data rate is very low compared to the measured amount of raw data. Therefore, the efficiency of the mud pulse telemetry must be improved, so that the data could be transmitted at higher rates. The present research work presents different developed and tested concepts for increasing the efficiency and the data transmission rate of the mud pulse telemetry. Both, the transmitter and the receiver end, were taken into consideration by developing the new concepts. Different hardware and software tools were used for performing the present research work. The available flow loop test facility and the experimental prototypes of the mud siren and positive pulser were used. The test facility was extended in order to enable the investigation of the new concepts. The available 3D numerical model (ANSYS CFX) was modified and extended in order to study the new concepts. At the transmitter end, a novel concept for a hybrid mud pulse telemetry system was developed and successfully tested. Here, two different types of mud pulse telemetry could be used in a combination, such as a mud siren and a pressure pulser. The developed concept was registered at the German Patent and Trade Mark Office for a patent in 2018. Two concepts for a multi-frequency mud siren were developed for simultaneous generation of two frequencies. In the first approach, two sets of stator/rotor were installed in a row connection, while they were installed in a parallel connection in the second approach. The two concepts were registered at the German Patent and Trade Mark Office for patents in 2015. An experimental multi-frequency generator was built and used for testing of several new ideas, such as transmitting the data using several carrier frequencies at the same time, transmitting the data with different wave forms (sine, sawtooth, triangle and rectangle), or transmitting the data using the chirp modulation. The innovative design of the experimental multi-frequency generator was registered at the German Patent and Trade Mark Office for patents in 2016. At the receiver end, two different methods for processing and analyzing the received multi-frequency signals using the Wavelet and Fourier analysis were drafted and tested. A novel concept for the use of a multi-sensor receiver was developed and successfully tested. The use of a multi-sensor receiver could strongly improve the detection of the received signals.:Table of Contents Declaration ii Abstract iii Acknowledgements v Table of Contents vi List of Abbreviations x List of Symbols xii CHAPTER 1 Introduction 1 CHAPTER 2 Modern Drilling Technology and Low Data Transmission Rate as a Limitation 5 2.1 Introduction to the modern drilling technology 5 2.1.1 Directional drilling technology 5 2.1.2 Steering technology 6 2.1.3 Measuring technology 8 2.1.4 Technology of data transmission in boreholes 9 2.2 Low data transmission rate as a problem with respect to the whole drilling process 13 CHAPTER 3 Fundamentals of Communication Technology 16 3.1 Modulation techniques for data transmission in baseband 16 3.2 Modulation techniques for data transmission in passband 17 3.3 Multiple frequency and chirp spread spectrum modulation techniques 19 3.4 Digital signal processing 21 3.4.1 Fourier transformation 21 3.4.2 Continuous wavelet transformation 23 3.4.3 Filtering 24 CHAPTER 4 State of the Art for Mud Pulse Telemetry Systems 26 4.1 Historical development of mud pulse telemetry including latest improvements applied for increasing its data transmission rate 26 4.2 Available types of mud pulse telemetry devices 30 4.2.1 Negative pulser 31 4.2.2 Positive pulser 32 4.2.3 Mud siren 32 4.2.4 Oscillating shear valve 33 4.3 Limitations of data transmission via mud pulse telemetry 34 4.3.1 Effect of noise sources in the mud channel on the transmission signal 34 4.3.2 Effect of attenuation in the mud channel on the transmission signal 36 4.3.3 Effect of reflections and their interference with the main transmission signal 37 4.3.4 Pass and stop bands 38 4.4.5 Minimum transmission time slot 38 CHAPTER 5 Novel Concepts and Tools for Increased Data Transmission Rates of Mud Pulse Telemetry 40 5.1 Transmitter end 41 5.1.1 Hybrid mud pulse telemetry (HMPT) 41 5.1.2 Multi-frequency generator 43 5.2 Receiver end 45 5.2.1 Investigation of the Wavelet analysis suitability for multi-frequency signal detection 45 5.2.2 Flexible placement of multi-sensor receiver 46 CHAPTER 6 Laboratory Test Facility and Used Hard and Soft Tools 49 6.1 Laboratory test facility for hydraulic data transmission in boreholes 49 6.2 Experimental prototypes of the pressure pulsers and mud siren 53 6.3 3D numerical simulation model for the test facility and mud siren 55 6.4 MATLAB software 58 CHAPTER 7 Hybrid Mud Pulse Telemetry (HMPT) System 59 7.1 Combination of mud siren and negative pressure pulser 60 7.2 Combination of mud siren and positive pressure pulser 63 7.3 Evaluating the laboratory investigations of the hybrid mud pulse telemetry (HMPT) system 66 CHAPTER 8 Mathematical and Numerical Investigation of the Concept of the Multi-Frequency Mud Siren 68 8.1 Preliminary considerations for the concept of the multi-frequency mud siren 69 8.2 Mathematical model investigation of different approaches for the multi-frequency mud siren concept 71 8.2.1 Multi-frequency mud siren with stators and rotors in a row 72 8.2.2 Multi-frequency mud siren with parallel connection of stators and rotors 74 8.3 Numerical model investigation of multi-frequency mud siren with two sets of stator/rotor in a row 77 8.3.1 Numerical simulations for data transmission with a multi-frequency mud siren using two carrier frequencies 79 8.3.2 Evaluation of the simulation results 81 8.3.3 Increasing the transmission reach of the mud siren for deep drilling operations 83 CHAPTER 9 Laboratory Investigations of Multi-Carrier Hydraulic Data Transmission Using an Experimental Multi-Frequency Generator 85 9.1 Laboratory multi-carrier frequency transmission tests 87 9.2 Investigation of the Wavelet analysis suitability for the detection of multi-frequency signal transmitted in boreholes 95 9.3 Initial investigations of hydraulic data transmission using chirp modulation and different pressure wave forms 100 9.3.1 Data transmission using chirp modulation (Chirp Spread Spectrum, CSS) 100 9.3.2 Data transmission using different wave forms 101 CHAPTER 10 Investigation of the Use of a Multi-Sensor Receiver for Improving the Hydraulic Data Transmission in Boreholes 104 10.1 Numerical model investigation of the use of a multi-sensor receiver 104 10.1.1 Data transmission using single-input and multiple-output (SIMO) 104 10.1.2 Data transmission using multiple-input and multiple-output (MIMO) 107 10.2 Laboratory investigations of the use of a multi-sensor receiver 108 10.3 Evaluating the use of a multi-sensor receiver for improving the hydraulic data transmission in boreholes 112 CHAPTER 11 Conclusion and Outlook 116 11.1 Conclusion 116 11.2 Outlook 120 References 122 List of Figures 129 List of Tables 136 List of Publications 137 List of Patents 138 Appendix- Chapter 7 139 Appendix- Chapter 8 141 Appendix- Chapter 9 142 Appendix- Chapter 10 146