ROLLER CONE MINING BIT CATALOG MANUAL

TABLE OF CONTENTS ROLLER CONE MINING BIT CATALOG 3 ROCK BIT DESIGNATION AND DESIGN FEATURES 3 8 Roller bit designation system (product lines, prefixes, suffixes) The IADC roller bit classification system 9 SPECIFICATIONS 9 11 11 12 12 Tungsten carbide insert bits (Chart C-1) Milled tooth bits (Chart C-2) Standard nozzle list (Chart C-3) Stabilizers (Chart C-4) Roller cone bit subs (Chart C-5) MANUAL 14 SECTION 1. ROCK FAILURE 14 15 18 1.1 Rock failure mechanics 1.2 Drilling practices selection 1.3 Practical use of bit runs results 19 SECTION 2. AIR CIRCULATION SYSTEM 19 20 21 21 22 2.1 Bottom hole cleaning 2.2 Required drilling rig compressor output 2.3 Nozzles selection 2.4 Nozzles replacement 2.5 On-site compressor output measurement 24 SECTION 3. GUIDELINES TO ROCK BIT OPERATION 25 33 SECTION 4. DULL BIT ANALYSIS SECTION 5. SELECTION OF EFFICIENT ROCK BIT DESIGNS 33 33 34 34 34 35 35 5.1 Mining and geological drilling conditions analysis 5.2 Technological drilling conditions analysis 5.3 Rock bit performance statistics analysis 5.4 Dull bit analysis and reasons bit failed 5.5 Rock bit cutting structure and bearing design features analysis 5.6 Analysis of techno-economic indicators of rock bits performance basing on bit test results 5.7 Training at Volgaburmash Training Center 36 SECTION 6. ROCK BITS STORAGE AND TRANSPORTATION 37 APPENDICES 42 CONTACT INFORMATION 2

ROCK BIT DESIGNATION AND DESIGN FEATURES ROLLER BIT DESIGNATION SYSTEM 250.8 V - ALS 74 Y R824-1 Bit diameter, mm Product line Modification by bit and leg (prefixes) Design number Modification by cone (suffixes) First two IADC code figures PRODUCT LINES (series by bearing types) АUL N V sealed bearing: radial journal bearing elastomer seal floating split bushing ball bearing thrust journal bearing with a thrust washer radial journal bearing open bearing: roller bearing ball bearing thrust journal bearing radial journal bearing thrust journal bearing open bearing: roller bearing ball bearing thrust journal bearing roller bearing thrust journal bearing PREFIXES SUFFIXES A АС jet circulation center circulation X Y Z chisel inserts conical inserts other shape inserts L shirttail and leading edge hardfacing T P enhanced teeth hardfacing near gauge of tungsten carbide inserts LL S leg leading edge hardfacing and enhanced shirttail hardfacing leg protection with tungsten carbide compacts G GG W single gauge of tungsten carbide compacts double gauge of tungsten carbide compacts enhanced heel row АUL PRODUCT LINE Radial journal bearing Elastomer seal Floating split bushing Ball bearing Thrust journal bearing with a thrust washer Tungsten carbide insert bit 9 7/8 AUL-ALS72Y-R976 Radial journal bearing ROLLER CONE MINING BIT CATALOG 3

ROCK BIT DESIGNATION AND DESIGN FEATURES ROLLER BIT DESIGNATION SYSTEM N PRODUCT LINE Roller bearing Ball bearing Thrust journal bearing Radial journal bearing Tungsten carbide insert bit 6 N-A51Y-R281 Milled tooth bit 6 1/4 N-ALS21-R256 Thrust journal bearing V PRODUCT LINE Roller bearing Ball bearing Thrust journal bearing Roller bearing Tungsten carbide insert bit 9 7/8 V-ALS42Y-R430 Thrust journal bearing Milled tooth bit 12 5/8 V-A31-R198M 4 ROLLER CONE MINING BIT CATALOG

ROCK BIT DESIGNATION AND DESIGN FEATURES ROLLER BIT DESIGNATION SYSTEM V-CONFIGURATION BEARING Tungsten carbide thrust button Air cooling passages Thrust bearing Air exit Ball plug PREFIXES PREFIXES USED FOR VARIOUS CIRCULATION TYPES A jet circulation АС center circulation PREFIXES USED FOR VARIOUS SHIRTTAIL AND LEG PROTECTION CONFIGURATIONS L leg leading edge and shirttail hardfacing LL leg leading edge and enhanced shirttail hardfacing www.vbm.ru 5

ROCK BIT DESIGNATION AND DESIGN FEATURES ROLLER BIT DESIGNATION SYSTEM S leg protection with tungsten carbide compacts SUFFIXES X chisel inserts Y conical inserts Z other shape inserts T enhanced milled tooth hardfacing Р near gauge of tungsten carbide inserts G single gauge of tungsten carbide compacts GG double gauge of tungsten carbide compacts 6 ROLLER CONE MINING BIT CATALOG

ROCK BIT DESIGNATION AND DESIGN FEATURES ROLLER BIT DESIGNATION SYSTEM BEARING PROTECTION Valve assembly The air passes through the bit bearing for proper cooling and maximized bearing life. Compressed air Air tubes Snap ring Valve washer Washer peripheral slots Return spring Retaining ring with inner clamp OPEN VALVE Compressed air Circular contact ledge Elastic coating Seat Pin bore Pin thread Pin ledge While drilling the air flows into the bit shank, the valve washer is moved down by the air inside the shank cavity allowing the air to flow through the washer peripheral slots to the bottom hole through special replaceable nozzles and through air tubes to the bearing air passages. CLOSED VALVE Bearing air passages Ball plug Leg air passages When the air flow stops, the valve washer is returned to its original position by the return spring, thus preventing rock cuttings from running into the bit body cavity. www.vbm.ru 7

ROCK BIT DESIGNATION AND DESIGN FEATURES THE IADC ROLLER BIT CLASSIFICATION SYSTEM The classification system of the International Association of Drilling Contractors is based on a 4-character code which describes a bit design and formation types that the bit is designed for. First three characters are numeric and the 4 th character is alphabetic. The sequence of numeric characters is defined as «series, type, bearing / gage». The 4 th alphabetic character describes «features available». Х Х Х Х Bit cutting structure series (1-8) Features available (A-Z) Bit cutting structure type (1-4) Bearing design features (1-7) CUTTING STRUCTURE SERIES first character: Eight categories of cutting structure series correspond to general formation characteristics. Series 1 through 3 refer to milled tooth bits. Series 4 through 8 refer to tungsten carbide insert bits. Within steel tooth and insert bit groups, formations become harder and more abrasive as the Series numbers increase. А FEATURES AVAILABLE forth character: Sixteen (16) alphabetic characters are used to indicate special cutting structures, bearings, hydraulic configurations and body gage protection. Some bit designs may have more than one of optional features. In such cases the most critical feature is indicated. air application Each Series is divided into 4 types depending on degrees of formation hardness. Type 1 refers to bits designed for the softest formation within the Series. Type 4 refers to the hardest formation within the Series. 1 open (non-sealed ) bearing 2 open bearing for drilling with air circulation 3 open bearing + tungsten carbide compacts on cone gage 4 sealed roller bearing 5 sealed roller bearing + tungsten carbide compacts on cone gage 6 sealed journal bearing 7 CUTTING STRUCTURE TYPES second character: BEARING DESIGN third character: sealed journal bearing + tungsten carbide compacts on cone gage 8,9 standby for future use В C D E G H J L M S T W X Y Z sealed bearing, special bearing seal allowing for higher RPM center jet special cutting structure design for deviation control extended jets enhanced gage/body protection with hardfacing or tungsten carbide compacts horizontal/steering application jet deflection lug pads with tungsten carbide compacts motor application standard steel tooth bit two cone bit enhanced cutting structure mostly chisel inserts conical inserts other shape inserts EXAMPLES OF IADC CODE: 212G a milled tooth rock bit designed to drill medium formations (21), an open bearing for air application (2), enhanced leg and shirttail protection with hardfacing and tungsten carbide compacts (G). 742Х a tungsten carbide insert bit designed to drill hard formations (74), an open bearing for air application (2), mostly chisel inserts (X). 8 ROLLER CONE MINING BIT CATALOG

Diameter Inch mm Bit Description Volgaburmash System SPECIFICATIONS TUNGSTEN CARBIDE INSERT BITS GOST 20692-2003 IADC GOST 50864-96 Pin Size API 7-2 Recommended Drilling Parameters RPM WOB, kn Net Weight Weight, kg Chart C-1 Gross Weight Wooden Box* 1. 5 1/8 130.2 N-A61X-R291 ТЗ-ПГН 612X З-76 2 7/8 Reg 115-60 40-110 10.4 13.4 10.9 2. 5 1/8 130.2 N-AC61X-R236 ТЗ-ПН 612CX З-76 2 7/8 Reg 115-60 40-110 8.0 11.0 8.5 3. 5 1/4 133.4 N-AC51Y-R260 МЗ-ПН 512CY З-76 2 7/8 Reg 115-60 20-90 7.0 10.9 7.5 4. 5 3/8 136.5 N-A51Y-R298 МЗ-ПГН 512Y З-76 2 7/8 Reg 115-60 20-90 11.7 15.6 12.4 5. 5 3/8 136.5 N-AC51Y-R265 МЗ-ПН 512CY З-76 2 7/8 Reg 115-60 20-90 8.5 12.4 9.2 6. 5 5/8 142.9 N-AC54X-R274 СЗ-ПН 542CX З-88 3 1/2 Reg 115-60 20-100 10.0 13.9 10.7 7. 5 7/8 149.2 N-A51Y-R266 МЗ-ПГН 512Y З-88 3 1/2 Reg 115-60 20-100 15.0 18.9 15.9 8. 5 7/8 149.2 N-A61Y-R259 ТЗ-ПГН 612Y З-88 3 1/2 Reg 115-60 40-120 15.0 18.9 15.9 9. 5 7/8 149.2 N-AC62X-R243 ТЗ-ПН 622CX З-88 3 1/2 Reg 115-60 40-120 13.0 16.9 13.9 10. 6 152.4 N-A51Y-R281 МЗ-ПГН 512Y З-88 3 1/2 Reg 115-60 20-100 15.0 19.5 15.7 11. 6 152.4 N-A61Y-R277 ТЗ-ПГН 612Y З-88 3 1/2 Reg 115-60 50-130 15.0 19.5 15.7 12. 6 1/4 158.7 V-ALS61Y-R406 ТЗ-ПГВ 612Y З-88 3 1/2 Reg 115-60 20-110 19.0 23.5 19.7 13. 6 3/4 171.4 V-ALS41Y-R830 МЗ-ПГВ 412Y З-88 3 1/2 Reg 115-60 30-120 19.0 23.5 19.7 14. 6 3/4 171.4 V-ALS51XY-R246M1 МЗ-ПГВ 512XY З-88 3 1/2 Reg 115-60 30-120 19.0 23.5 19.7 15. 6 3/4 171.4 V-ALS62X-R237М1 ТЗ-ПГВ 622X З-88 3 1/2 Reg 115-60 50-140 19.0 23.5 19.7 Cardboard Box** 16. 6 3/4 171.4 V-ALS62Y-R278M ТЗ-ПГВ 622Y З-88 3 1/2 Reg 115-60 50-140 19.0 23.5 19.7 17. 6 3/4 171.4 V-ALS63Y-R408 ТКЗ-ПГВ 632Y З-88 3 1/2 Reg 115-60 50-140 19.0 23.5 19.7 18. 6 3/4 171.4 V-ALS72Y-R247M1 К-ПГВ 722Y З-88 3 1/2 Reg 115-60 80-150 18.8 23.3 19.5 19. 7 3/8 187.3 V-ALS52Y-R426 МЗ-ПГВ 522Y З-88 3 1/2 Reg 115-60 30-130 30.0 35.0 31.1 20. 7 1/2 190.5 V-ALS52Y-R426М МЗ-ПГВ 522Y З-88 3 1/2 Reg 115-60 30-130 31.0 36.0 32.1 21. 7 7/8 200 V-ALS41Y-R834 МЗ-ПГВ 412Y З-117 4 1/2 Reg 115-60 30-140 35.0 40.0 36.1 22. 7 7/8 200 V-ALS51Y-R458 МЗ-ПГВ 512Y З-117 4 1/2 Reg 115-60 30-140 35.0 40.0 36.1 23. 7 7/8 200 V-ALS62Y-R244 ТЗ-ПГВ 622Y З-117 4 1/2 Reg 115-60 60-170 35.0 40.0 36.1 24. 7 7/8 200 V-ALS63Y-R808-1 ТКЗ-ПГВ 632Y З-117 4 1/2 Reg 115-60 60-170 35.0 40.0 36.1 25. 7 7/8 200 V-ALS72Y-R407 К-ПГВ 722Y З-117 4 1/2 Reg 115-60 90-180 31.0 36.0 32.1 26. 8 1/2 215.9 V-AS42Y-R938 МЗ-ПГВ 422Y З-117 4 1/2 Reg 115-60 60-180 32.7 37.7 34.3 27. 8 1/2 215.9 V-ACS61X-R235M ТЗ-ПВ 612CX З-117 4 1/2 Reg 115-60 60-180 38.0 43.0 39.6 28. 8 1/2 215.9 V-AS61X-R895 ТЗ-ПГВ 612X З-117 4 1/2 Reg 115-60 60-180 35.0 40.0 36.6 29. 8 1/2 215.9 V-ALS63Y-R980 ТКЗ-ПГВ 632Y З-117 4 1/2 Reg 115-60 60-180 35.0 40.0 36.6 30. 9 228.6 V-ALS51Y-R268 МЗ-ПГВ 512Y З-117 4 1/2 Reg 115-60 110-220 49.0 45.3 41.6 31. 9 228.6 V-ALS42Y-R429 МЗ-ПГВ 422Y З-117 4 1/2 Reg 115-60 70-190 41.0 46.3 42.6 32. 9 228.6 V-ALS41YP-R900 МЗ-ПГВ 412YP З-117 4 1/2 Reg 115-60 30-150 40.0 54.3 50.6 33. 9 228.6 V-ALS52Y-R436 МЗ-ПГВ 522Y З-117 4 1/2 Reg 115-60 70-190 40.5 45.8 42.1 34. 9 228.6 V-ALS61Y-R431-1 ТЗ-ПГВ 612Y З-117 4 1/2 Reg 115-60 70-190 40.5 45.8 42.1 35. 9 228.6 V-ALS63Y-R554 ТКЗ-ПГВ 632Y З-117 4 1/2 Reg 115-60 70-190 40.5 45.8 42.1 36. 9 3/16 233.0 V-ALS63Y-R554М ТКЗ-ПГВ 632Y З-117 4 1/2 Reg 115-60 70-190 41.7 47.0 43.3 37. 9 5/8 244.5 V-ALS42Y-R509 МЗ-ПГВ 422Y З-121 4 1/2 FH 115-60 40-150 50.0 56.0 51.4 38. 9 5/8 244.5 V-ALS63Y-R981 ТКЗ-ПГВ 632Y З-121 4 1/2 FH 115-60 120-220 45.0 47.0 42.4 39. 9 5/8 244.5 V-AS74Y-R901 К-ПГВ 742Y З-121 4 1/2 FH 115-60 110-220 41.0 47.0 42.4 www.vbm.ru 9

Diameter Inch mm Bit Description Volgaburmash System SPECIFICATIONS TUNGSTEN CARBIDE INSERT BITS GOST 20692-2003 IADC GOST 50864-96 Pin Size API 7-2 Recommended Drilling Parameters RPM WOB, kn Net Weight Weight, kg Chart C-1 Gross Weight Wooden Box* 40. 9 5/8 244.5 V-ALS83Y-R261У ОК-ПГВ 832Y З-121 4 1/2 FH 115-60 120-240 52.4 58.4 53.8 41. 9 7/8 250.8 V-ALS51Y-R257-1 МЗ-ПГВ 512Y З-152 6 5/8 Reg 115-60 40-170 62.0 69.6 64.7 42. 9 7/8 250.8 V-ALS41Y-R801 МЗ-ПГВ 412Y З-152 6 5/8 Reg 115-60 40-170 62.0 69.6 64.7 43. 9 7/8 250.8 V-ALS42Y-R430 МЗ-ПГВ 422Y З-152 6 5/8 Reg 115-60 40-170 62.0 69.6 64.7 44. 9 7/8 250.8 V-ALS51Y-R580 МЗ-ПГВ 512Y З-152 6 5/8 Reg 115-60 110-230 62.0 69.6 64.7 45. 9 7/8 250.8 V-ALS52Y-R968 МЗ-ПГВ 522Y З-152 6 5/8 Reg 115-60 110-230 60.8 68.4 63.5 46. 9 7/8 250.8 V-ALS62Y-R484 ТЗ-ПГВ 622Y З-152 6 5/8 Reg 115-60 80-210 63.0 70.6 65.7 47. 9 7/8 250.8 V-ALS63Y-R833-1 ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 80-210 62.0 69.6 64.7 48. 9 7/8 250.8 V-ALS63Y-R907 ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 80-210 62.0 69.6 64.7 49. 9 7/8 250.8 V-ALS72Y-R482 К-ПГВ 722Y З-152 6 5/8 Reg 115-60 110-230 62.0 69.6 64.7 50. 9 7/8 250.8 AUL-ALS72Y-R976 К-ПГАУ 727Y З-152 6 5/8 Reg 115-90 150-280 62.0 69.6 64.7 51. 9 7/8 250.8 V-ALS74Y-R824-1 К-ПГВ 742Y З-152 6 5/8 Reg 115-60 110-230 62.0 69.6 64.7 52. 10 3/16 258.0 V-ALS63Y-R833-1M ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 80-210 63.0 70.6 65.7 53. 10 3/16 258.0 AUL-ALS72Y-R976М К-ПГАУ 727Y 3-152 6 5/8 Reg 115-90 150-280 63.0 70.6 65.7 54. 10 3/16 258.0 V-ALS74Y-R824-1М К-ПГВ 742Y З-152 6 5/8 Reg 115-60 120-240 64.5 72.4 67.5 55. 10 3/16 258.0 V-ALS72Y-R482М К-ПГВ 722Y З-152 6 5/8 Reg 115-60 120-240 64.8 72.1 67.2 Cardboard Box** 56. 10 5/8 269.9 V-ALS42YGG-R889 МЗ-ПГВ 422Y З-152 6 5/8 Reg 115-60 40-180 78.0 87.5 81.0 57. 10 5/8 269.9 V-ALS43Y-R271M МЗ-ПГВ 432Y З-152 6 5/8 Reg 115-60 40-180 78.0 87.5 81.0 58. 10 5/8 269.9 V-ALS52Y-R921 МЗ-ПГВ 522Y З-152 6 5/8 Reg 115-60 40-180 78.0 87.5 81.0 59. 10 5/8 269.9 V-ALS52Y-R531 МЗ-ПГВ 522Y З-152 6 5/8 Reg 115-60 40-180 78.0 87.5 81.0 60. 10 5/8 269.9 V-ALS61Y-R880 ТЗ-ПГВ 612Y З-152 6 5/8 Reg 115-60 80-220 78.0 87.5 81.0 61. 10 5/8 269.9 V-ALS62Y-R423 ТЗ-ПГВ 622Y З-152 6 5/8 Reg 115-60 80-220 78.0 87.5 81.0 62. 10 5/8 269.9 V-ALS63Y-R919 ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 80-220 78.0 87.5 81.0 63. 10 5/8 269.9 V-ALS63Y-R817 ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 80-220 78.0 87.5 81.0 64. 10 5/8 269.9 V-ALS72Y-R424 К-ПГВ 722Y З-152 6 5/8 Reg 115-60 120-240 76.0 85.5 79.0 65. 11 279.4 V-ALS62Y-R428 ТЗ-ПГВ 622Y З-152 6 5/8 Reg 115-60 80-230 76.0 85.5 79.0 66. 11 279.4 V-ALS63YGG-R899 ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 80-230 76.0 85.5 79.0 67. 11 279.4 V-ALS73Y-R433 К-ПГВ 732Y З-152 6 5/8 Reg 115-60 130-250 76.0 85.5 79.0 68. 12 1/4 311.1 V-ALS52Y-R425 МЗ-ПГВ 522Y З-152 6 5/8 Reg 115-60 50-210 100.0 110.0 104.2 69. 12 1/4 311.1 V-ALS62Y-R470 ТЗ-ПГВ 622Y З-152 6 5/8 Reg 115-60 90-260 100.0 110.0 104.2 70. 12 1/4 311.1 V-ALS62Y-R950 ТЗ-ПГВ 622Y З-152 6 5/8 Reg 115-60 90-260 100.0 110.0 104.2 71. 12 1/4 311.1 V-ALS63Y-R868 ТКЗ-ПГВ 632Y З-152 6 5/8 Reg 115-60 90-260 100.0 110.0 104.2 72. 12 1/4 311.1 V-ALS72Y-R466 К-ПГВ 722Y З-152 6 5/8 Reg 115-60 140-280 100.0 110.0 104.2 73. 12 1/4 311.1 V-ALS74Y-R462 К-ПГВ 742Y З-152 6 5/8 Reg 115-60 140-280 100.0 110.0 104.2 74. 12 1/4 311.1 V-ALS74YGG-R594 К-ПГВ 742Y З-152 6 5/8 Reg 115-60 140-280 100.0 110.0 104.2 75. 13 3/4 349.2 V-ALS52Y-R530 МЗ-ПГВ 522Y З-152 6 5/8 Reg 115-60 50-240 154.0 168.0 160.0 76. 13 3/4 349.2 V-ALS62Y-R491 ТЗ-ПГВ 622Y З-152 6 5/8 Reg 115-60 100-290 154.0 168.0 160.0 77. 13 3/4 349.2 V-ALS74Y-R489 К-ПГВ 742Y З-152 6 5/8 Reg 115-60 160-310 154.0 168.0 160.0 78. 15 1/2 393.7 V-ALS63Y-R434 ТКЗ-ПГВ 632Y З-177 7 5/8 Reg 115-60 120-320 190.0 208.5 195.7 10 ROLLER CONE MINING BIT CATALOG

SPECIFICATIONS MILLED TOOTH BITS Chart C-2 Bit Description Pin Size Recommended Drilling Parameters Weight, kg Diameter Inch mm Volgaburmash System GOST 20692-2003 IADC GOST 50864-96 API 7-2 RPM WOB, kn Net Weight Gross Weight Wooden Box* Cardboard Box** 1. 5 1/8 130.2 N-AC12T-R264 М-ПН 122C З-76 2 7/8 Reg 115-60 30-80 8.0 11.0 8.5 2. 5 7/8 149.2 N-AC21-R422 С-ПН 212C З-88 3 1/2 Reg 115-60 40-110 13.0 16.9 13.9 3. 6 1/4 158.7 N-ALS21-R256 С-ПГН 212 З-88 3 1/2 Reg 115-60 20-120 16.0 20.4 16.7 4. 8 1/2 215.9 V-ACS31-R234 Т-ПВ 312C З-117 4 1/2 Reg 115-60 100-180 36.0 41.0 37.6 5. 9 7/8 250.8 V-ALS21-R452 С-ПГВ 212 З-152 6 5/8 Reg 115-60 110-210 55.0 62.6 57.7 6. 12 5/8 320.0 V-A31-R198M Т-ПГВ 312 З-152 6 5/8 Reg 115-60 140-260 105.0 115.0 109.2 * ** The weight of bits packed into wooden boxes may differ from values shown on the list depending on kinds of the wood used and its moisture content. The weight of bits packed into cardboard boxes may differ from values shown on the list depending on the quantity of sealing elements used. STANDARD NOZZLE LIST Chart C-3 Nozzle description Bit diameter, mm Nozzle outlet hole diameter, mm 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 24 25 26 28 30 32 R4803 130.2-154.2 * * * * * * * * * * R4166 155.6-171.4 * * * * * * * * * * * R4117 187.3-228.6 * * * * * * * * * * * * * * R3381 R11010* 244.5-311.1 * * * * * * * * * * * * * R8519 349.2-393.7 * * * * * * * * * * * * * * * * R11010 nozzle is made of plastic. www.vbm.ru 11

SPECIFICATIONS STABILIZERS Above-bit stabilizers are designed to decrease radial runouts and bit shocks while drilling. Stabilizer 9 7/8 CНД 167х12х1/4/152 Description: С - stabilizer НД - above-bit Description Configuration Weight, Thread connection kg Н М 1. 250.8 СНД 167х12х1/6/152 with 68 tungsten carbide inserts 67 167х12х1/6 3-152 2. 250.8 СНД 167х12х1/4/152 with 68 tungsten carbide inserts 67 167х12х1/4 3-152 3. 250.8 СНД 167х12х1/6/121 with 68 tungsten carbide inserts 74 167х12х1/6 3-121 4. 250.8 СНД 167х12х1/4/121 with 68 tungsten carbide inserts 74 167х12х1/4 3-121 Chart C-4 ROLLER CONE BIT SUBS Subs are designed to connect the bit to the drilling assembly. Bit sub ПСП 165х10/152 Н ПСП Н/М А Description Configuration Description: П - sub СП - special thread Н - pin М - box В - extended А - protected ПСП Н/М М ПСП Н/М ВА Chart C-5 Overall dimensions, mm Thread Weight, connection D L d S b kg Н М 1. ПСП 165 х 10 / 121 w/o tungsten carbide inserts 197-1 250±2 70 170-1 105±1 22 165х10 З-121 2. ПСП 165 х 10 / 152 w/o tungsten carbide inserts 197-1 290±2 93 170-1 145±1 20 165х10 З-152 3. ПСП 167 х 12 / 121 А with 48 tungsten carbide inserts 197-1 300±2 80 +5-0,3 170-1,9 90±0,5 39 167х12 З-121 4. ПСП 167 х 12 / 152 А with 48 tungsten carbide inserts 197-1 300±2 80 +5-0,3 170-1,9 90±0,5 31 167х12 З-152 5. ПСП 167 х 12 / 121 ВА with 104 tungsten carbide inserts 197-1 450±2 80 +5-0,3 170-1,9 170±1 70 167х12 З-121 6. ПСП 167 х 12 / 152 ВА with 104 tungsten carbide inserts 197-1 450±2 80 +5-0,3 170-1,9 170±1 62,5 167х12 З-152 12 ROLLER CONE MINING BIT CATALOG

SECTION 1. ROCK FAILURE 1.1 ROCK FAILURE MECHANICS Efficient rock drilling requires an optimum combination of many factors, one of which is dynamic load or an impact energy that the bit cutting structure is subjected to. Area of optimal loads The depth of insert penetration depends on the load applied to it. Figure 1 illustrates this regularity in a form of a polygonal line with 4 main areas of rock failure (a, b, c, d) under it. Figure 2 illustrates the rock failure schematics in the process of penetration of one insert. Figure 1 When only minor impact energy is applied there is only minor fragmentation made by the insert on the rock surface (residual deformation). This results in the rock cracking around the insert contour. With further increase in impact energy the rock commences to chip away from the insert contour. This is the first phase of rock failure. The force resulting in the insert contour chipping is called the load of the first phase of rock failure. The further increase in the impact energy up to the load of the second phase of failure results only in an insignificant increase in the volume of failure. When maximum load is applied the volume of destruction increases proportionately. This type of failure is called the second phase of destruction. Figure 2 Figure 2 illustrates: 1 Insert -rock contact surface; 2 Rock failure crater; 3 Cutting cross-section. 14 ROLLER CONE MINING BIT MANUAL

SECTION 1. ROCK FAILURE 1.2 DRILLING PRACTICES SELECTION Conditions for a phase in rock failure b, d (Figure 1) depend on the properties of the rock, weight on bit, rotation speed and bottom hole cleaning conditions. Optimization of drilling parameters is attained via experimental selection of WOB and RPM. Specifications shown for WOB and RPM of the bit type should not be exceeded. In order to determine the most suitable bit cutting structure selection please refer to Chart M-1 Rocks Classification. The Chart shows a variety of formations and their classification per IADC code, GOST 20692-2003, strength coefficient as per the scale of professor M. Protodjakonov, drillability category, ultimate uniaxial compression strength, etc. A relation between the bottom hole penetration δ per one rotation and WOB while drilling with a roller cone bit is illustrated. Figure 3 illustrates the relation as a curve. Three main areas of rock failure are illustrated under it. Figure 3 Area I Abrasion rock failure. Micro chipping, crushing and movement of some very small rock chips. The initial chart illustrates insufficient WOB. ROP is not more than 3m/hr. Area II - Fatigue failure. Deeper insertion of the inserts and rotation result in rock fatigue and resultant spalling of cuttings or rock chips. Very hard formations are drilled mainly in this area. ROP is not more than 10 m/hr. Area III A bulk failure area where specific power inputs per one unit of rock volume are considerably lower than in the first two areas but ROP is higher. www.vbm.ru 15

SECTION 1. ROCK FAILURE ROCKS CLASSIFICATION Chart M-1 16 ROLLER CONE MINING BIT MANUAL

SECTION 1. ROCK FAILURE www.vbm.ru 17

SECTION 1. ROCK FAILURE When bit RPM is altered, the quantity of inserts impacts against the bottom hole per a time unit changes. As this takes place the penetration per one rotation δ can be expressed by ROP: ROP = n δ Figure 4 Figure 4 illustrates how the volume of bit penetration per one rotation δ and ROP depend on rotation speed of the bit. With increased RPM in n n 1 section, the values of ROP and δ increase. With increased RPM in n 1 n n 2 section, δ decreases, but ROP continues to grow. With the further increase in RPM of the bit in n>n 3 section, the values of δ and ROP decrease considerably. ROP decreases after the point n 3 due to: - reduced insert-rock contact time; - decreased impact energy applied to an insert; - increased drilling rod misalignment; - changed mode of the air flow motion at the bottom hole; - increased power consumption. Continuous air circulation in the process of drilling ensures the bottom hole cleanness, the bit bearing cooling and contributes to the effective formation penetration. An optimum ratio of the value of a bit penetration per one rotation δ and ROP on Figure 4 corresponds to bit RPM n оpt. A further increase in the RPM will result in erosion of the bit cutting structure and bearing with no further performance benefit. 1.3 PRACTICAL USE OF BIT RUNS RESULTS The maximum ROP is determined experimentally for each bit type and size in given mining and geological conditions. Therefore an optimum ratio of WOB and RPM is theoretically reached, when the insert penetration into the rock is around 80% of protrusion. 20% remain for efficient cuttings removal. In practice the recommended drilling parameters for a particular bit type and size shall be determined using Charts C-1 and C-2. The target is to determine the maximum ROP with the given WOB and RPM. Excessive WOB at which an insert penetration into the rock is over 80% results in the following: - cuttings will not be completely removed from the area of failure; - rock is milled again; - ROP decreases; - bit cutting structure and bearing wear intensively; - load on the drilling rig spinner increases. 18 ROLLER CONE MINING BIT MANUAL

SECTION 2. AIR CIRCULATION SYSTEM 2.1 BOTTOM HOLE CLEANING An optimum air circulation assurance in up-to-date drilling with mining bits boils down to the following tasks: 1. To ensure efficient cuttings removal from the bottom hole to the surface. 2. To reduce the cutting structure and bearing erosive wear by means of efficient bottom hole cleaning. 3. To cool the bearing and to keep the bearing clean. An effective bottom hole cleaning objective comes to obtaining the required annular return velocity. The annular return velocity produces a lifting force that ensures cuttings removal. It can be controlled by: - selection of a compressor and its adjustment to the optimum air capacity; - rock bit size and drill rod OD selection; - selection of replaceable nozzles with an optimum flow area and their installation into the bit. Actual compressor output changes depending on the throttle flap position, wear of the screw pair and the compressor body, altitude above the sea level and manifold leakage. Factors that affect the value of the annular return velocity for cuttings removal: - correlation between a bit diameter and a drill pipe OD; - drill rod gage loss as a result of their wear; - rock specific weight; - sizes and shapes of cuttings; - water in the hole. They can be expressed by the following formula: Q = 47 V (DB 2 DP 2 ) where Q air flow, m 3 /min; DB Bit Diameter, m DP Pipe Diameter, m V desired air velocity, m/sec; It should be noted that: - the air velocity for light weight rock drilling is to be not lower than 25 m/sec; - the air velocity for heavy weight rock drilling is to be not lower than 35 m/sec; - the air velocity for drilling of formations with high water content is to be not lower than 50 m/sec. www.vbm.ru 19

Bit diameter Recommended drill rod diameter mm Inch mm Inch SECTION 2. AIR CIRCULATION SYSTEM 2.2 REQUIRED DRILLING RIG COMPRESSOR OUTPUT Chart M-2 illustrates the required value of a compressor output versus air velocity, rock bit diameter and drill rod diameter. Chart M-2 Compressor output, m 3 /min for desired air velocity: 25 m/sec 35 m/sec 50 m/sec 76 3 60 2 23/64 3 4 5 93 3 2/3 60 2 23/64 6 9 12 65 2 9/16 6 8 11 60 2 23/64 7 10 14 98.4 3 7/8 65 2 9/16 6 9 13 73 2 7/8 5 7 10 65 2 9/16 10 15 21 114.3 4 1/2 73 2 7/8 9 13 18 89 3 1/2 6 8 12 60 2 23/64 13 18 26 65 2 9/16 12 17 24 120.6 4 3/4 73 2 7/8 11 15 22 89 3 1/2 8 11 6 102 4 5 7 10 73 2 7/8 14 19 27 130.2 5 1/8 89 3 1/2 11 15 21 102 4 8 11 15 73 2 7/8 16 22 31 136.5 5 3/8 89 3 1/2 13 18 25 102 4 1/64 10 14 19 89 3 1/2 14 19 27 139.7 5 1/2 102 4 1/64 11 15 21 114 4 31/64 8 12 17 73 2 7/8 18 25 35 142.9 5 5/8 89 3 1/2 15 21 29 102 4 1/64 12 17 24 114 4 31/64 9 13 19 102 4 1/64 14 19 28 149.2 5 7/8 114 4 31/64 11 15 22 127 5 7 10 14 102 4 1/64 15 21 30 152.4 6 114 4 31/64 12 17 24 127 5 8 12 17 89 3 1/2 20 28 41 158.7 6 1/4 102 4 1/64 17 24 35 114 4 31/64 14 20 29 127 5 11 15 21 102 4 1/64 22 31 45 171.4 6 3/4 114 4 31/64 19 27 38 127 5 16 22 31 140 5 33/64 12 16 23 114 4 31/64 26 36 52 127 5 22 31 45 187.3 7 3/8 140 5 33/64 18 26 37 152 5 63/64 14 20 28 159 6 17/64 12 16 23 140 5 33/64 24 34 48 200 7 7/8 152 5 63/64 20 28 39 159 6 17/64 17 24 35 168 6 39/64 14 19 27 Bit diameter Recommended drill rod diameter mm Inch mm Inch 215.9 8 1/2 228.6 9 233.0 9 3/16 244.5 9 5/8 250.8 9 7/8 269.9 10 5/8 279.4 11 295.3 11 3/5 311.1 12 1/4 320.0 12 5/8 349.2 13 3/4 393.7 15 1/2 Compressor output, m 3 /min for desired air velocity: 25 m/sec 35 m/sec 50 m/sec 140 5 33/64 32 44 63 152 5 63/64 27 38 55 159 6 17/64 25 35 50 168 6 39/64 21 30 43 168 6 39/64 28 39 56 178 7 24 34 48 180 7 3/32 23 33 47 191 7 33/64 19 26 38 197 7 3/4 16 22 32 168 6 39/64 31 43 61 178 7 27 37 53 180 7 3/32 26 36 51 191 7 33/64 21 29 42 197 7 3/4 18 25 36 178 7 33 46 49 180 7 3/32 32 44 48 191 7 33/64 27 38 41 197 7 3/4 25 34 37 203 8 22 30 33 178 7 37 51 74 180 7 3/32 36 50 72 191 7 33/64 31 44 62 197 7 3/4 28 40 57 203 8 25 36 51 219 8 5/8 18 25 35 203 8 37 52 74 219 8 5/8 29 41 58 229 9 24 34 48 203 8 43 61 86 219 8 5/8 35 50 71 229 9 1/64 30 42 60 203 8 54 76 108 219 8 5/8 46 65 92 229 9 1/64 41 57 82 235 9 1/4 38 53 75 219 8 5/8 57 80 115 229 9 52 73 105 235 9 1/4 49 68 98 254 10 38 53 76 273 10 3/4 26 37 52 229 9 1/64 59 82 118 235 9 1/4 55 78 111 254 10 45 62 89 254 10 67 94 135 273 10 3/4 56 78 111 305 12 34 48 68 305 12 73 102 145 311 12 1/4 68 96 137 330 13 54 76 108 The above calculation gives a preliminary estimate of required compressor output. The final data can be obtained only after a test drilling. 20 ROLLER CONE MINING BIT MANUAL

SECTION 2. AIR CIRCULATION SYSTEM 2.3 NOZZLES SELECTION Optimum combination of drilling equipment on a drilling rig, i.e. bit diameter, drill rod OD, actual compressor output for given mining and geological conditions makes it possible to gain the required annular return velocity and satisfactory bottom hole cleaning and cuttings removal. The better the bottom hole cleaning and cuttings removal, the less the erosive wear of the cutting structure and the bearing at maximum ROP. However it is very important to realize that an air circulation system of a bit is to ensure not only the required annular return velocity but to provide conditions for the best cooling and keeping the bearing clean. This problem is solved solely by the choice of bit nozzles diameter because only nozzles selection makes it possible to gain an air pressure drop in a bit which is required for successful drilling. Recommended air pressure in a bit is determined in each case experimentally by making measurements with a special measuring tool as illustrated in the photo. The long-term experience in drilling of blast holes at mines reveals that the air pressure in a bit is to be within the range of not less than 0.20 0.22 MPa (29.7-32.6 psi) and has to correspond to physical-mechanical properties of formations and drilling conditions. Non-observance of the recommended values of air pressure in a bit will inevitably result in premature bearing failure. 2.4 NOZZLES REPLACEMENT Nozzles are fixed with a nail-shaped retaining pin. The nail is installed through a hole in the leg and fills in the ring groove made in the nozzle recess in the leg and in the nozzle. Such method of retention is the most reliable and facilitates nozzles replacement. Nozzles replacement procedure: 1. Remove the retaining pin to remove the nozzle 2. Remove the nozzle 3. Install a new nozzle 4. To fix the nozzle install the retaining pin with a hammer www.vbm.ru 21

SECTION 2. AIR CIRCULATION SYSTEM 2.5 ON-SITE COMPRESSOR OUTPUT MEASUREMENT The subject method makes it possible to measure an actual drilling rig compressor output on-site taking into account its wear, air circulation system leakage and other factors stated above. Values obtained with the method are true only for Volgaburmash bits when their air passages are free from cuttings. It is recommended to measure compressor output in the following order: 1. Determine the bit type and size and its condition. Only new or effective bits can be used. 2. Determine what the nozzles flow area is. Be sure that all three nozzles are the same. 3. When the compressor is switched on check the air flow under the cones in order to make sure that all air passages are empty. The compressor shall operate with a nominal working temperature and with water supply switched on. 4. Determine air temperature with the instruments in the operator s cabin. 5. Install a pressure gage into one of the nozzles and measure the pressure. 6. Basing on the corresponding bit and nozzle diameter find compressor output on the chart. 7. For your calculation use correction factors in Charts M-4, M-5, M-6: working level altitude above the sea level, temperature of air pumped into the bit, ambient temperature. Chart M-3 COMPRESSOR OUTPUT (m 3 /min) for 244.5 269.9 mm (9 5/8 10 5/8 ) bits МРа NOZZLES DIAMETER, mm 11 12 14 16 17 19 22 24 0.1 10 12 14 16 19 21 28 31 0.11 11 12 14 17 20 22 29 32 0.12 11 13 15 18 20 23 30 34 0.13 12 14 16 19 21 24 32 35 0.14 12 14 16 20 22 25 33 37 0.15 13 15 17 20 23 26 34 38 0.16 13 15 18 21 24 27 36 40 0.17 14 16 18 22 25 28 37 41 0.18 14 17 19 23 26 29 39 43 0.19 15 17 20 24 27 31 40 45 0.20 15 18 20 24 28 32 41 46 0.21 16 18 21 25 29 33 43 48 Chart M-4 ALTITUDE ABOVE SEA LEVEL CORRECTION FACTOR МРа ALTITUDE ABOVE SEA LEVEL, m 0 500 1000 1500 2000 2500 3000 3500 4000 4500 0.1 1 1.03 1.06 1.09 1.13 1.17 1.21 1.27 1.33 1.41 0.11 1 1.03 1.06 1.09 1.13 1.17 1.22 1.28 1.35 1.43 0.12 1 1.03 1.06 1.10 1.14 1.18 1.23 1.29 1.36 1.45 0.13 1 1.03 1.06 1.10 1.14 1.19 1.24 1.30 1.38 1.46 0.14 1 1.03 1.06 1.10 1.15 1.19 1.25 1.31 1.39 1.48 0.15 1 1.03 1.07 1.11 1.15 1.20 1.26 1.32 1.40 1.49 0.16 1 1.03 1.07 1.11 1.15 1.21 1.26 1.33 1.41 1.50 0.17 1 1.03 1.07 1.11 1.16 1.21 1.27 1.34 1.42 1.52 0.18 1 1.03 1.07 1.11 1.16 1.21 1.28 1.35 1.43 1.53 0.19 1 1.03 1.07 1.12 1.16 1.22 1.28 1.35 1.44 1.54 0.20 1 1.04 1.07 1.12 1.17 1.22 1.29 1.36 1.44 1.55 0.21 1 1.04 1.08 1.12 1.17 1.23 1.29 1.36 1.45 1.55 22 ROLLER CONE MINING BIT MANUAL

SECTION 2. AIR CIRCULATION SYSTEM Chart M-5 BIT TEMPERATURE (t 0 С) CORRECTION FACTOR t 0 С in bit Factor - 20 1.08-10 1.06 0 1.04 10 1.02 20 1.00 30 0.98 40 0.97 50 0.95 60 0.94 70 0.92 80 0.91 90 0.90 100 0.89 110 0.87 120 0.86 130 0.85 140 0.84 Chart M-6 AMBIENT TEMPERATURE (t 0 С) CORRECTION FACTOR Ambient t 0 С Factor - 40 0.80-30 0.83-20 0.86-10 0.90 0 0.93 10 0.97 20 1.00 30 1.03 40 1.07 50 1.10 60 1.14 70 1.17 80 1.20 Example 1: Selection of air circulation parameters for efficient rock bit operation on СБШ-250МНА-32 drilling rig. Basic Data: 250.8 V-ALS74Y-R824 rock bit; Bit nozzles: 19 mm x 3 nozzles; Altitude above sea level: 500 m; Air temperature in bit: +30 0 C; Ambient temperature: -10 0 C; Drill rod diameter: 203 mm; Formations: ferruginous quartzite; Holes contain no water. 1. Measure the pressure with the pressure gage included into the set. 0.18 MPa 2. 3. 4. 5. Chart M-3: 244.5-269.9. Find the corresponding compressor output basing on the changed pressure (0.18 MPa) and nozzles sizes ( 19 мм x 3 nozzles) Chart M-4. Find correction factor for the altitude above sea level (500 m). According to the chart it is 1.03: Chart M-5. Find correction factor for the air temperature in the bit (+ 30 0 C). According to the chart it is 0.98: Chart M-6. Find correction factor for the ambient temperature (-10 0 C). According to the chart it is 0.90: 29 m 3 /min 29 x 1/03 = 29.87 m 3 /min 29.87 x 0.98 = 29.27 m 3 /min 29.27 x 0.90 = 26.34 m 3 /min 6. Actual compressor output on СБШ-250МНА-32 drilling rig is 26.34 m 3 /min. 7. 8. Basing on Chart M-2 we determine that the required air velocity (35 m/s) is not ensured (with 203 mm drilling rod, with the actual compressor output of 26.34 m 3 /min, when drilling in heavy, no water formations). However, when the drilling rod is replaced by a 219 mm one, the compressor with 26.34 m 3 /min output ensures the required air velocity (35 m/sec). In order to extend the bit bearing life time it is required to have pressure in the bit not lower than 0.2 MPa. Replace the three nozzles by 17.5 mm ones. 9. The second measurement of the pressure in the bit. 0.21 MPa Therefore, we have selected nozzles and air velocity required for an effective bit operation. www.vbm.ru 23

SECTION 3. GUIDELINES TO ROCK BIT OPERATION Our recommendations will allow you to obtain good bit performance. BEFORE DRILLING 3.1. Inspect the drill pipe spinner spindle thread condition. If the thread condition is unsatisfactory the spindle is to be replaced. 3.2. Inspect the drill rods condition. Do not use curved rods or a worn thread. 3.3. Inspect the bushings condition. Do not use worn bushings. 3.4. Inspect compressor functionality basing on the pressure gage reading on the outlet as compared to its specification data. Adjust the flap position if necessary. 3.5. Inspect the air ducts and hoses for leakage. Fix the leakage found in the system. 3.6. Inspect the operability of control instrumentation. 3.7. Inspect operability of hoisting jacks. Do not allow loosing the drilling rig horizontalizing while drilling. 3.8. Inspect the bit condition and completeness, reliability of the fixture and operation of the relieve valve, availability and size of nozzles, connection thread condition. 3.9. Do not make unauthorized changes to the bit design. 3.10. Flush the drilling assembly with air before the bit screwing on. 3.11. Screw the bit on with no impacts and shifts. 3.12. Select nozzles so that the pressure in the bit would not be less than 0.2 MPa. WHILE DRILLING 3.13. Fill in the Bit Record Card for each bit. (Appendix No.1). 3.14. Break in a new bit for 15 minutes with the drill rod rotation at 30 RPM and WOB of 10% of the upper limit recommended in the bit specification. Break in a new bit in a new hole (except for the first row holes) with the compressor on. 3.15. Smoothly apply the operation parameters recommended in the bit specification. Do not exceed the WOB and RPM indicated in the specification. 3.15.1 If with sequential increase in WOB the ROP does not increase or decreases then the WOB shall be reduced to the earlier registered level at which the maximum ROP was obtained. 3.15.2 If the drill rod starts vibrating then the bit RPM or WOB shall be reduced to the level at which the vibration stops. 3.16. Optimum drilling parameters shall be determined only by experiment. The most critical factor is the maximum ROP. 3.17. Perform drilling only with the compressor on. 3.18. Do not apply weight on the bit when it does not rotate. 3.19. Do not drill when the bit cones are balled up and do not rotate. 3.20. Do not drill when the bit air ducts are blocked. 3.21. Do not complete an old hole with a new bit. It can result in shirttail and hill row inserts cracking and cones locking. 3.22. Perform tripping and hole conditioning only with the drilling assembly rotating and the compressor on. 3.23. Do not use new or test bits to clean out collapsed holes. Always apply a used bit for this purpose. 3.24. Emergency drilling stop and leaving a bit at the bottom hole with the compressor off may result in plugged bearing and locked cones. 3.24.1 Lift the bit above the bottom hole by 1.5 2 meters with no rotation. Turn on the compressor and flush the bit. While doing so, control the pressure increase in the drilling rig air line with a pressure gage. 3.24.2 Trip the bit out of the hole, clean the bit, control cones rotations by hand, turn the compressor on, visually check flushing air through the cones. 3.24.3 You can continue drilling with the bit if the bit examination results are satisfactory for the drilling rig operator. 3.24.4 If the bit examination results are not satisfactory for the drilling rig operator then the bit shall be removed for its repair at the bits preparation shop. 3.25. Before the bit starts to drill a new hole clean, flush and examine it. 3.26. Use bits till they have obvious failure symptoms: - locking of bearing at least in one cone; - big play resulting in cones jamming and interference; - rollers and balls come out of at least of one cone bearing; - teeth (inserts) from one cone interfere with other cones. - excessive wear of the cones cutting structure; - bit failure (bearing failure, welding seams cracking, cones cracking and other); AFTER DRILLING 3.27. Dull bits intended for repair and drilling of not completed holes or for cleaning of backfilled holes shall be flushed and cleaned from mud, their bearing and thread shall be lubricated. It is not recommended to use new bits in repair operations. 3.28. Dull bits intended for utilization shall be: 3.28.1 Examined by the drilling rig operator, and registered in bit registry and in the Dull Bit Condition Report (Appendix No.2). 3.28.2 Disassembled in order to have a stock of effective parts, i.e. relieve valves and nozzles on site. 3.29. Bit Records and Dull Bit Condition Report shall be delivered to the engineer in charge of rock bit record keeping for Bit Run Statistics review (Appendix No.3). 3.30. A normative indicator of the bit work is determined basing on Bit Run Statistics for a specific mine by an average performance of no less than 50 bits of the similar size and type and designation, with a Report issued. 3.31. A report on dull bit run statistics including meters drilled, hours and ROP shall be delivered to the manufacturer. 24 ROLLER CONE MINING BIT MANUAL

BROKEN TEETH (ВТ) SECTION 4. DULL BIT ANALYSIS Teeth break flush to cone steel. Cause: - Too high RPM of the spinner; - Broken, desintegrated formation either while drilling or spudding a hole; - Improper rock bit; - Alteration of formations including very hard ones. Remedy: - Reduce the spinner RPM; - Drill sections interbedded with very hard formations with reduced WOB and RPM; - Select a bit with the cutting structure features fitting the drilling conditions. CHIPPED TEETH (СТ) Chipped tungsten carbide inserts. Cause: - Excessive WOB; - Broken, desintegrated formation either while drilling or spudding a hole; - Wrong tungsten carbide inserts grade; - Cone interference. Remedy: - Revise the drilling conditions and WOB; - Reduce WOB and gradually reduce RPM; - Select a bit with more wear resistant tungsten carbide inserts. LOST TEETH (LТ) Tungsten carbide inserts came out of the cone. Very often a reason for that is junk at the bottom hole. Cause: - Metal on the bottom hole; - Cone shell erosion; - A crack in the cone that loosens the grip on the insert. - Excessive WOB. Remedy: - Reduce WOB and RPM (as an option you can use both actions in complex). - Select a bit with features that are more suitable for the application. www.vbm.ru 25

WORN TEETH (WT) SECTION 4. DULL BIT ANALYSIS Inserts wear blunt. Slow penetration rates. Cause: - Excessive WOB; - Carbide grade does not match the rock properties; - Formations changed and are interbedded with hard abrasive stringers; - Excessive RPM; - This dulling characteristic can be considered as a standard one if the values of meters drilled and hours are high. Remedy: - Reduce WOB and RPM (as an option one can use both actions in complex); - Select a bit with another shape of inserts and with a more wear resistant carbide grade. - Select a bit with features that are more suitable for the application. HEAT CHECKING (HC) Inserts surface is worn specifically and looks like a snake skin. It very often results in inserts breakage. Cause: - Carbide grade does not correspond to formations drilled; - Inserts are heated in the process of drilling and at the same time they are cooled with water injected into the hole with air and by underground waters. Remedy: - Select a bit with carbide grade which is less prone to heat checking (higher cobalt content or bigger grain size); - Reduce RPM and water supply. ROUNDED GAUGE (RG) The gage inserts are rounded towards the center of the bit. Slow penetration rates. Cause: - Excessive RPM; - Carbide grade does not match the formation hardness. Remedy: - Reduce RPM; - Use a bit with a more wear resistant carbide grade; - Use a bit with a lesser offset and a bigger journal angle. 26 ROLLER CONE MINING BIT MANUAL

SECTION 4. DULL BIT ANALYSIS TRACKING (ТR) Inserts are worn mainly on one side. This is a dulling characteristic which occurs when the inserts mesh like a gear into the bottom hole formation. Cause: - Usually caused by improper WOB and RPM; - Improper bit selection; - Changes in the formation. Remedy: - Adjust WOB and rotation so that the proper rock shattering within a particular time period is achieved; - Select a bit better suited for the application or a bit with an irregular skip pitch. SELF-SHARPENING WEAR (SS) This is a dulling characteristic which occurs when inserts wear in a manner such that they retain a sharp crest shape. This dulling characteristic indicates proper bit selection and operating parameters. EROSION (ER) Cone steel erodes away from inserts and results in inserts loss. Also, excessive leg erosion can result in inserts loss on the bit leg and in shirttail wear. Cause: - High abrasiveness of the formation drilled; - Inadequate air volume passing through the nozzles to the bottom hole; - Wet (from either ground water or excessive water injection), sticky, and abrasive formations; - Excessive air circulation speed. Remedy: - Select WOB and RPM to achieve maximum ROP ; - Inspect air delivery system of the drilling rig for leaks; - If using water dust control reduce water supply. Make sure that the nozzles are not plugged. - Inspect cuttings removal efficiency; - Increase nozzle size to reduce air pressure; - Proceed with drilling and do not change drilling parameters if high ROP. www.vbm.ru 27

CRACKED CONE (СС) SECTION 4. DULL BIT ANALYSIS The cone cracks either axially or circumferentially. Cause: - Cone steel fatigue; - Cone interference causing the cone to heat and generate cracks; - Excessive WOB; - Dropped drill rod. Remedy: - This dulling characteristic can be allowed if the drilling is long; - Reduce WOB; - Review the drilling conditions and make sure that the bit drills the bottom hole smoothly with no impacts; - Monitor and control wear of drill rod threaded joints. LOST CONE (LC) Cones are left at the bottom hole. Cause: - The bit overdrilled the bottom hole. - Bit hitting bottom; - Bearing failure (all rollers and balls came out). Remedy: - Observe instructions in the bit manual; - Monitor and control wear of drilling rod threaded joints. CONE INTEFERENCE (CI) Bearing wear results in the teeth (inserts) from one cone interfering with another cone. It often results in intermittent cone locking and inserts deterioration and radial cone breakage. Cause: - Excessive WOB resulting in exaggerated bending moment of journals; - Plugged air to bearing passage resulting bearings being starved of coolant; - Roller bearing wear, excessive thrust or eccentric drilling caused by bent steel, the thread wear or drilling rig table bushing resulting in thrust flange breakage; - Insufficient air volume transferred to the bearing; - Running a bit down an undersized hole; - Rollers and balls come out of one cone. Remedy: - Reduce WOB; - Inspect drilling rods condition, their diameter wear and deviation; - Inspect drilling assembly bushings for wear; - Check the relieve valve availability as well as availability and proper selection of bit nozzles. 28 ROLLER CONE MINING BIT MANUAL

CONE DRAGGED (CD) All three cones are locked. The cones have typical tracks (flats) caused by inserts sliding at the bottom hole. Cause: - Drilling with an air compressor switched off or failed; - Air supply stopped or is insufficient due to air hose tear or big air leakage in the circulation system; - A foreign object jammed between the cones; - Bit balling up. Remedy: - Repair and adjust the compressor; - Eliminate air leakage in the system; - Follow the instructions in the bit manual. SECTION 4. DULL BIT ANALYSIS CORED BIT (CR) Nose parts of the cones are missing or worn. Cause: - Excessive WOB resulting in the cone body being in contact or heating the bottom hole; - Inadequate hole cleaning causing cone erosion; - Nose parts of the cones of center jet bits badly wear while drilling of abrasive formations due to sand blasting effect resulting in lost inserts and worn nose parts; - Junk at the bottom hole. Remedy: - Reduce WOB; - Select inserts projection, shape, diameter and quantity on the rows so that the cone body would not be in contact and would not hit the bottom hole; - Measure the actual compressor output, drill rod diameter and control the nozzles selection; - Replace the center jet bit by a jet bit. BALLED-UP BIT (BU) Formation is packed between the cones. (It can be erroneously considered as the bearing locking). Cause: - Inadequate hydraulic cleaning of the bottom hole. - Forcing the bit into formation cuttings with the compressor off; - Drilling a sticky formation. Remedy: - Increase the speed of air flow by nozzles selecting; - When you plan a blackout inform the drilling rig operator in advance; - Examine the bit after each drilled hole. www.vbm.ru 29

SECTION 4. DULL BIT ANALYSIS BROKEN LEG (BL) One or all three legs are missing. It often happens as a result of the operator s error or failed equipment. Cause: - The drill rod lost in the hole while tripping or repair. Remedy: - Periodically examine the thread on the spinner spindle sub. In case of a wear or damage of turn of thread replace the sub. PINCHED BIT (PB) (mechanically damaged bit) On inner rows the inserts are chipped. Between the rows of one cone there are traces of the adjacent cone. Cause: - Hole redrilling with a new bit; - Cleaning out of an existing holes with a new bit. Remedy: - Use a worn bit to clean out or redrill a hole; - If there are no worn bits drill a new hole adjacent to old hole; - Order undersized bits for hole cleaning; - Have a stock of dull bits good for hole redrilling or cleaning. PLUGGED NOZZLE (PN) A nozzle plugged with cuttings or rubber hose scraps. The compressor discharges air through the valve. Significant erosion of the bit shirttails and legs. Cause: - The bit was left at the bottom hole with air off for workover and for power transmission line switching; - The valve protecting from cuttings failed or is missing in the bit; - The compressor failed, the air hose fell off. Remedy: - Use a dull bit for workover; - When you plan a blackout inform the drilling rig operator in advance; - Periodically examine the relieve valve in the bit, its operability and the fixture reliability. Replace the valve by an effective one if it is necessary; - Forbid using bits that have no valve protecting from cuttings; - Adjust the compressor, eliminate air leakage in the system, clean the bit from cuttings (nozzles and air tubes in the legs); - Flush the drill rod with air before screwing the bit on. 30 ROLLER CONE MINING BIT MANUAL

LOST NOZZLE (LN) A plugged nozzle usually results in a sharp pressure drop while drilling and requires an immediate trip out of the hole. Cause: - Breaking the rules of nozzle installation; - Mechanical damage of nozzles or their retention system; - Nozzles or their fixture erosion; - Bit balling up. Remedy: - Examine the bit after each drilled hole. SECTION 4. DULL BIT ANALYSIS OFF-CENTER WEAR (ОС) Excessive wear of one or two legs (legs, shirttails); of one or two cones (gage and hill rows), along with bearings failure; cones locking and lost rollers and balls. Cause: - The drill rod is bent resulting in off center bit rotation (radial runout); - The bit is screwed on the sub with a warp, the bit thread is damaged. Remedy: - Inspect the drill rod rotation for eccentricity; - Inspect the bit for damaged thread; - Inspect and replace the bit sub if its thread is damaged. SHIRTTAIL DAMAGE (SD) Leg shirttail that protects bearing rollers is broken. Cause: - Axial part of the load on the bearing results in the shirttail bearing a part of the load; - Axial runout when the bit rotates; - Erosion weakens the shirttail structure. Remedy: - Reduce WOB and select a bit with a smaller journal angle and bit axis; - Inspect the bit for off center wear and the drilling rods for a bent; - Inspect the bit thread and the sub thread for damage; - Inspect the drill rod, compressor and the air line for leakage. www.vbm.ru 31

BEARING SLUDGING (BS) Sludge in the bit bearing. (It can be erroneously considered as the bearing locking). Cause: - Insufficient compressor output; - Improper nozzles selection; - Drilling with a relieve valve removed; - The bit was left at the bottom hole for a long time with a compressor off. Remedy: - Select nozzles following the recommendations; - When you plan a blackout inform the drilling rig operator in advance; - Run the bit with a relieve valve available. SECTION 4. DULL BIT ANALYSIS PLAY (PL) Play. Cause: - Insufficient compressor output; - Improper nozzles selection; - Roll and ball bearings wear, bearing overheating resulted in journal bearing failure. Remedy: - Repair the compressor or replace it to a more efficient one; - Select nozzles according to the recommendations; - Examine the bit after each drilled hole. 32 ROLLER CONE MINING BIT MANUAL

SECTION 5. SELECTION OF EFFICIENT ROCK BIT DESIGNS More than 84 rock bit types and sizes have been developed and can be manufactured for mining companies. It is important to select effective rock bit designs for particular mining and geological drilling conditions and to provide rock bit services to ensure the best performance including: - reduced expenses for drilling equipment and drilling operations; - increased drilling rigs productivity; - reduced time for blast blocks preparation. Our specialists give all recommendations on the optimum bit types and sizes selection and analyze the efficiency of bit runs. Efficient bit selection at each mining company is made basing on a complex assessment of mining, geological and technological drilling conditions; rock bit performance statistics; dull bit analysis; cutting structure and design features; technical and economic indexes of bits performance basing on test results. We can design and manufacture rock bits basing on our customer s specific requirements. 5.1 MINING AND GEOLOGICAL DRILLING CONDITIONS ANALYSIS A critical factor that affects a bit performance is the mining and geological drilling conditions analysis. Rock properties, namely ultimate uniaxial compression strength, alteration, inclusions, attitude of beds, water cut, abrasiveness, broken ground formations, etc. determine rock bit specification and design features. Since geology may alter with a mine contour deepening and widening it is important to consider the drilling volume as per Long Term Drilling Operations Plan. 5.2 TECHNOLOGICAL DRILLING CONDITIONS ANALYSIS Intensive mining complex development is directly related to technical re-equipment and replacement of existing drilling rigs to the state-of-the-art equipment. Such technical characteristics of drilling rigs as productivity, drilling rod assembly, jointing thread, compressor output shall correspond to design features of bits. It is obvious that it is impossible to achieve a considerable economic effect in drilling using the state-of-the-art bits on an old and worn drilling rig. At the same time it is well possible to reduce drilling expenses by selection of bits which efficiency would correspond to actual drilling rig technical parameters. www.vbm.ru 33

SECTION 5. SELECTION OF EFFICIENT ROCK BIT DESIGNS 5.3 ROCK BIT PERFORMANCE STATISTICS ANALYSIS The evaluation database for an efficient rock bit design selection is Rock Bit Performance Statistics Analysis (Appendix 3). Modern drilling companies usually use a few bit types of different manufacturers and it is important to make a comparative assessment of their efficiency not taking into account the bits cost. Example 2: A and B rock bits comparison assessment with the following statistics: A rock bit, Bit Life (BL A ) = 60 meters drilled, Bit Hours (BH A ) = 10 hrs; B rock bit, Bit Life (BL B ) = 40 meters drilled, Bit Hours (BH B ) = 8 hrs. Let s determine the average ROP of A and B bits performance: Example 3: C and D rock bits comparison assessment with the following statistics: C rock bit, Bit Life (BL C ) = 60 meters drilled, Bit Hours (BH C ) = 10 hrs; D rock bit, Bit Life (BL D ) = 60 meters drilled, Bit Hours (BH D ) = 12 hrs. Let s determine the average ROP of C and D bits performance: ; ; Conclusion: Rock bit A is more effective than rock bit B, because BL A > BH A, ROP A > ROP B. Conclusion: Rock bit C is more effective than rock bit D, because ROP C > ROP D. If the meters drilled and ROP of two bits are equal then the bits are equal in their efficiency. 5.4 DULL BIT ANALYSIS AND REASONS BIT FAILED After assessment of bits efficiency basing on statistics it is necessary to make a comparative analysis of each bit type dulling and reasons. The analysis results are important because it is critical to very precisely determine what bit design features are required for the application. The evaluation database for dull bit analysis is Dull Bit Grading Report (Appendix 2). 5.5 ROCK BIT CUTTING STRUCTURE AND BEARING DESIGN FEATURES ANALYSIS As a rule for the optimization of a rock bit design features selection specialists in drilling at mines use a method for bits identification basing on the information provided by manufacturers. It is a list of products at web-sites and in catalogues with bits specification. The information contains alphabetic characters as per GOST 20692-2003 and the designation as per IADC code. 34 ROLLER CONE MINING BIT MANUAL

SECTION 5. SELECTION OF EFFICIENT ROCK BIT DESIGNS 5.6 ANALYSIS OF TECHNO-ECONOMIC INDICATORS OF ROCK BITS PERFORMANCE BASING ON BIT TEST RESULTS A bit design efficiency is determined basing on comparative test results in equal mining and geological conditions. An efficient bit design shall be considered the one that ensures the minimum value of operational expenses for drilling of one running meter of a hole which is determined by the formula: ; Example 4: Calculation of А and В bits efficiency: Indexes A Rock bit B Rock bit % Diff Bit Cost $4,500 $4,500 Bit Life (meters) 5,000 4,500-10% Bit Hours 200 150-25% ROP 25 30 +20% Rig Cost/hour $500 $500 Bit Cost /metre $0.90 $1.00 +10% TDC/metre $20.90 $17.70 TDC Savings/metre $3.20 TDC/Bit $104,500 $79,650 Total Savings $24,850 +24% Therefore the drilling with rock bit B is more economic as the total savings are $24,850. 5.7 TRAINING AT VOLGABURMASH TRAINING CENTER Specialists of mining companies are challenged to optimize drilling as rock bits nomenclature broadens and old drilling rigs are replaced by the-state-ofthe-art ones. In order to assist in solving the problems Volgaburmash, JSC set up a Training Center where the specialists of the Mining Products Engineering Group provide a 3 days training course on Up-to-Date Miming Bits: Production and Operation program. www.vbm.ru 35

SECTION 6. ROCK BITS STORAGE AND TRANSPORTATION 6.1. Rock bits shall be stored in a dry and enclosed facility. 6.2. Rock bits shall be stored at a warehouse in cardboard or wooden boxes placed on pallets. 6.3. The transportation shall be made either on pallets or in boxes (without pallets). 6.4. The transportation shall be made by all modes of transport in conformity with cargo transportation rules for each mode of transport subject to protection from atmospheric precipitations and mechanical damage. 6.5. Storage and transportation of bits in bulk is borbidden. 6.6. Bits shall not hit each other or other solid objects while handling. 6.7. Gloves shall be used when handling rock bits. 8 1/2 bits and bigger diameter bits shall be handled using a mechanized equipment. 6.8. Rock bits shall be stored at drilling rigs in the manufacturer s package or with their shanks upwards and the thread and the relief valve protected by a cap. 36 ROLLER CONE MINING BIT MANUAL

CONVERSION TABLE LENGTH mm m inch foot mm 1 mm 1 0.001 0.03937 0.003281 m 1 m 1000 1 39.3701 3.2808 inch (in) 1 inch 25.4 0.0254 1 0.08333 foot (ft) 1 foot 304.8 0.3048 12 1 WEIGHT kg tn lb kg 1 kg 1 1000 2.2046 t 1 tn 1000 1 2204.6 lb 1 lb 0.45359 4.5359*10-4 1 PRESSURE bar atm MPa kg/cm 2 psi (lb/in 2 ) bar 1 bar 1 0.98692 0.1 1.01972 14.504 atm 1 atm 1.01325 1 0.10132 1.03323 14.696 MPa 1 MPa (N/m 2 ) 10 9.8692 1 10.197 145.0377 kg/cm 2 1 kg/cm 2 0.98067 0.96784 0.09806 1 14.2233 psi (lb/in 2 ) 1 psi (lb/in 2 ) 0.06895 0.06805 6.89*10-3 0.07031 1 VOLUME l m 3 cf l 1 l (dm 3 ) 1 0.001 0.03531 m 3 1 m 3 1000 1 35.3146 cf (ft 3 ) 1 cf (ft 3 ) 28.3168 0.02831 1 CIRCULATION RATE l/min m 3 /min cfm l/min 1 l/min 1 0.001 0.03531 m 3 /min 1 m 3 /min 1000 1 35.3146 cfm (ft 3 /min) 1 cfm (ft 3 /min) 28.3168 0.02831 1 VELOCITY m/s km/h m/h ft/min m/s 1 m/s 1 3.6 3600 196.85 km/h 1 km/h 0.2778 1 1000 54.68 m/h 1 m/h 2.778*10-4 0.001 1 0.05468 ft/min 1 ft/min 0.00508 0.01828 18.2879 1 www.vbm.ru 37

Appendix 1

Appendix 2

Appendix 3 Appendix 4

Appendix 5

CONTACT INFORMATION VOLGABURMASH, JSC 1, Groznenskaya Str., Samara, 443004, Russia GENERAL DIRECTOR Phone: +7 (846) 330-30-70, 300-31-63 Fax: +7 (846) 330-27-52 E-mail: general@vbm.ru COMMERCIAL DEPARTMENT Phone: +7 (846) 330-30-79, 330-31-56, 300-80-34 Fax: +7 (846) 330-31-06 E-mail: market@vbm.ru SERVICE AND BIT RESEARCH DEPARTMENT Phone: +7 (846) 300-80-34, 330-29-90 E-mail: mining@vbm.ru www.vbm.ru 42

FOR NOTES