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Fragmentation prediction in bench blasting
42A 931314 Quality drilling and advanced measurement techniques Laitinen, T
Quarry Manage July 1992, P23-27 Quality drilling, characterised in terms of control of collaring and alignment accuracy, hole straightness, and hole length, shape, and diameter accuracy, is a prerequisite for quality and efficient blasting. The influences of the variation of these parameters on effective specific charge for a rock volume are examined. Total effects of poor drilling quality are assessed. Instrumental methods of monitoring the sensitive parameters and equipment selection to minimise their variation are described.
931315 COPROD - a revolution in rock-drilling technology Shelhammer, D Quarry Manage July 1992, P29-31 The COPROD concept combines the speed of top hammer drilling with the accuracy, equipment life, and hole dimension control of downhole drilling. It is based on a new drillstring design, with centre rods stacked one on top of each other inside tubes. The centre rods, which no not rotate, transfer impact energy to the bit, the tubes transfer rotational energy. The COPROD head, rockdrill, and drill rig are illustrated. Field test results on gabbro, limestone and copper ore demonstrate the combination of qualities of the COPROD system.
931316 Drilling induced pyrometamorphism of elastic sediments in the Lavo-1 well,Denmark Pedersen, A K; Nygaard, E; Ronsbo, J G; Koch, C B; Buchwald, V F
Sci Drilling V3, N4, 1992, P127-137 One of the primary aims of drilling is to identify a lithologic sequence. The thermal impact of techniques such as turbodrilling hampers lithological assessment by cuttings analysis, but thermal effects in traditional drilling are less common. Glassy rock was, however, seen in cores from depth 2.1km in Upper Triassic-Lower Jurassic sediments in the Lavo-I well. Detailed microscopic examination indicates extreme heating to 1000 deg C followed by rapid cooling.
Blasting See also." 931275. 931401 931318 Non-electric blast initiation. How to select the right system
Engng Min J 1/193, N5, May 1992, P16D-16E Safety, versatility, and simplicity are three reasons why nonelectric initiation systems are widely used in surface and underground mining. The five major categories and their attributes are described: cap and fuse, detonation cord, flash tube, low-energy cord, and gas mixture. The various hole configurations are illustrated: single downline, multiple downlines, loop-back downlines, downline with slides, and redundant downline with slides. The combinations to be selected on the basis of geology, hole depth, blast design, and vibration limitation are examined. 931319 Simulation of blasting induced rock motion using spherical element models Taylor, L M; Preece, D S
Engng Comput Vg, N2, April 1992, P243-252 Blasting-induced motion of rock controls the final shape and location of the muckpile. Discrete element methods with polygonal elements have been used to model blasting, but are computationally intensive due to the necessity to consider interactions of corners and sides of elements. Spherical elements were introduced to lower computing costs but the shortcoming existed of inability to treat bulking of the rock mass. This has been overcome by introducing bulking mechanisms which allow spherical elements to exert a torque on other spherical elements with which contact is made. The new code DMC (Distinct Motion Code) has been developed along these lines to take advantage of supercomputer vector processing capabilities. 931320 Water-based glycol systems acceptable substitute for oil-based muds Bland, R
Oil Gas J 1/90, N26, 29 June 1992, P54-59 Oil-based muds formulated to reduce shale swelling and maintain the stability of hydratable shales and prevent enlargement or collapse of the borehole have become environmentally unacceptable in some oil drilling areas. Water-based polypropylene glycol (PPG) systems are one alternative under investigation. Laboratory evaluation of these fluids as to their effects on shale swelling, lubrication, equilibrium gas hydrate formation,differential sticking, and sticking coefficient is described. Initial field applications confirm their suitability for use.
931317 Application of ultrahigh pressure water jet for rock drilling Yasuda, N; Hoshina, M Proc ISRM International Symposium on Static and Dynamic Considerations in Rock Engineering, Swaziland, 10-12 September 1990 P367-373. Publ Rotterdam: A A Balkema,
1990 The development of a high pressure water jet-assisted rock drill rig is described. Cutting tests with a single nozzle were first used to evaluate the structure of the jet and cutting parameters (width and depth of cut). Bits with 6 carbide inserts and 6, 8, or 10 nozzles were tested in the laboratory on andesite, rhyolite, and hard sandstone rocks. Field evaluation was against rhyolite. Performance comparisons with diamond and steel bits are made.
931321 Drilling the first horizontal well in the Gulf of Mexico: a case history of East Cameron Block 278 Well B-12 Fisher, E K; French, M R
S P E Drilling Engng V7, N2, June 1992, P86-92 The first horizontal well in the Gulf of Mexico had as a target high permeability, shallow, unconsolidated gas sands some 450m below mudline. The cost was less than that of an extended reach development well drilled from an offshore platform, increased drilling costs being more than compensated for by lower completion costs. The problems confronting the drilling engineers are described. Planning, equipment selection, and implementation of the project, including the control required to remain within the payzone, are discussed.
© 1993 Pergamon Press Ltd. Reproduction not permitted
Quarry Manage July 1992, P23-27 Quality drilling, characterised in terms of control of collaring and alignment accuracy, hole straightness, and hole length, shape, and diameter accuracy, is a prerequisite for quality and efficient blasting. The influences of the variation of these parameters on effective specific charge for a rock volume are examined. Total effects of poor drilling quality are assessed. Instrumental methods of monitoring the sensitive parameters and equipment selection to minimise their variation are described.
931315 COPROD - a revolution in rock-drilling technology Shelhammer, D Quarry Manage July 1992, P29-31 The COPROD concept combines the speed of top hammer drilling with the accuracy, equipment life, and hole dimension control of downhole drilling. It is based on a new drillstring design, with centre rods stacked one on top of each other inside tubes. The centre rods, which no not rotate, transfer impact energy to the bit, the tubes transfer rotational energy. The COPROD head, rockdrill, and drill rig are illustrated. Field test results on gabbro, limestone and copper ore demonstrate the combination of qualities of the COPROD system.
931316 Drilling induced pyrometamorphism of elastic sediments in the Lavo-1 well,Denmark Pedersen, A K; Nygaard, E; Ronsbo, J G; Koch, C B; Buchwald, V F
Sci Drilling V3, N4, 1992, P127-137 One of the primary aims of drilling is to identify a lithologic sequence. The thermal impact of techniques such as turbodrilling hampers lithological assessment by cuttings analysis, but thermal effects in traditional drilling are less common. Glassy rock was, however, seen in cores from depth 2.1km in Upper Triassic-Lower Jurassic sediments in the Lavo-I well. Detailed microscopic examination indicates extreme heating to 1000 deg C followed by rapid cooling.
Blasting See also." 931275. 931401 931318 Non-electric blast initiation. How to select the right system
Engng Min J 1/193, N5, May 1992, P16D-16E Safety, versatility, and simplicity are three reasons why nonelectric initiation systems are widely used in surface and underground mining. The five major categories and their attributes are described: cap and fuse, detonation cord, flash tube, low-energy cord, and gas mixture. The various hole configurations are illustrated: single downline, multiple downlines, loop-back downlines, downline with slides, and redundant downline with slides. The combinations to be selected on the basis of geology, hole depth, blast design, and vibration limitation are examined. 931319 Simulation of blasting induced rock motion using spherical element models Taylor, L M; Preece, D S
Engng Comput Vg, N2, April 1992, P243-252 Blasting-induced motion of rock controls the final shape and location of the muckpile. Discrete element methods with polygonal elements have been used to model blasting, but are computationally intensive due to the necessity to consider interactions of corners and sides of elements. Spherical elements were introduced to lower computing costs but the shortcoming existed of inability to treat bulking of the rock mass. This has been overcome by introducing bulking mechanisms which allow spherical elements to exert a torque on other spherical elements with which contact is made. The new code DMC (Distinct Motion Code) has been developed along these lines to take advantage of supercomputer vector processing capabilities. 931320 Water-based glycol systems acceptable substitute for oil-based muds Bland, R
Oil Gas J 1/90, N26, 29 June 1992, P54-59 Oil-based muds formulated to reduce shale swelling and maintain the stability of hydratable shales and prevent enlargement or collapse of the borehole have become environmentally unacceptable in some oil drilling areas. Water-based polypropylene glycol (PPG) systems are one alternative under investigation. Laboratory evaluation of these fluids as to their effects on shale swelling, lubrication, equilibrium gas hydrate formation,differential sticking, and sticking coefficient is described. Initial field applications confirm their suitability for use.
931317 Application of ultrahigh pressure water jet for rock drilling Yasuda, N; Hoshina, M Proc ISRM International Symposium on Static and Dynamic Considerations in Rock Engineering, Swaziland, 10-12 September 1990 P367-373. Publ Rotterdam: A A Balkema,
1990 The development of a high pressure water jet-assisted rock drill rig is described. Cutting tests with a single nozzle were first used to evaluate the structure of the jet and cutting parameters (width and depth of cut). Bits with 6 carbide inserts and 6, 8, or 10 nozzles were tested in the laboratory on andesite, rhyolite, and hard sandstone rocks. Field evaluation was against rhyolite. Performance comparisons with diamond and steel bits are made.
931321 Drilling the first horizontal well in the Gulf of Mexico: a case history of East Cameron Block 278 Well B-12 Fisher, E K; French, M R
S P E Drilling Engng V7, N2, June 1992, P86-92 The first horizontal well in the Gulf of Mexico had as a target high permeability, shallow, unconsolidated gas sands some 450m below mudline. The cost was less than that of an extended reach development well drilled from an offshore platform, increased drilling costs being more than compensated for by lower completion costs. The problems confronting the drilling engineers are described. Planning, equipment selection, and implementation of the project, including the control required to remain within the payzone, are discussed.
© 1993 Pergamon Press Ltd. Reproduction not permitted