C.6 Water-well casing
See Figures C.9 and C.10 and Tables C.14 and C.15.
Figure C.9 — Water-well casing with flush butt joints, according to BS 879
Figure C.10 — Water-well casing with screwed and socketed joints, according to BS 879
Table C.14 — Dimensions of water-well casings with flush butt joints
| Equipment | 4 in. | 5 in. | 6 in. | 8 in. | 10 in. | 12 in. | 13 in. | 15 in. | 18 in. | 21 in. | 24 in. | |||||||||||
| inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | |
| Casing OD | 4,50 | 114,30 | 5,50 | 139,70 | 6,62 | 168,30 | 8,62 | 219,10 | 10,75 | 273,00 | 12,75 | 323,90 | 14,00 | 355,60 | 16,00 | 406,60 | 19,00 | 482,80 | 22,00 | 558,80 | 25,00 | 635,00 |
| Nominal bore | 3,86 | 98,40 | 4,87 | 123,80 | 5,87 | 149,20 | 7,87 | 200,00 | 9,87 | 250,80 | 11,87 | 301,60 | 13,12 | 333,40 | 15,00 | 381,00 | 18,00 | 457,20 | 21,00 | 533,40 | 24,00 | 609,60 |
| Threads (inch) | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | |||||||||||
Table C.15 — Dimensions of water-well casings with screwed and socketed joints
| Equipment | 4 in. | 6 in. | 8 in. | 10 in. | 12 in. | 13 in. | 15 in. | 18 in. | 21 in. | 24 in. | ||||||||||
| inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | inch | mm | |
| Casing OD | 4,50 | 114,30 | 6,62 | 168,30 | 8,62 | 219,10 | 10,75 | 273,00 | 12,75 | 323,90 | 14,00 | 355,60 | 16,00 | 406,40 | 19,00 | 482,60 | 22,00 | 558,80 | 25,00 | 635,00 |
| Casing ID | 4,00 | 101,60 | 6,00 | 152,40 | 8,00 | 203,20 | 10,00 | 254,00 | 12,00 | 304,80 | 13,25 | 336,60 | 15,25 | 357,40 | 18,25 | 463,60 | 21,12 | 536,60 | 24,12 | 612,80 |
| Socket OD | 5,12 | 130,00 | 7,25 | 184,00 | 9,31 | 237,00 | 11,43 | 291,00 | 13,62 | 346,00 | 14,87 | 378,00 | 16,87 | 429,00 | 20,00 | 508,00 | 23,12 | 587,00 | 26,12 | 644,00 |
| Threads (inch) | 10 | 10 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | ||||||||||
C.7 Bit selection chart
See Table C.16.
Table C.16 — Bit selection chart
| Group | Rock description | Hardness abrasivity | TC | GTS | PDC | TSP | Surface set stones per carat | Impregnated type number | |||||||||
| 10/15 | 20/25 | 30/40 | 40/60 | 60/80 | 2 | 4 | 6 | 8 | 9 | 10 | |||||||
| 1 | Clay | Soft | |||||||||||||||
| Soft Shale | |||||||||||||||||
| Chalk | |||||||||||||||||
| Soft Limestone | |||||||||||||||||
| Gypsum | |||||||||||||||||
| Volcanic Tuff | |||||||||||||||||
| 2 | Sand Loose sandstone Shale Marble Medium limestone Salt |
Soft to medium | |||||||||||||||
| 3 | Soft sandstone | Med-hard low abrasivity |
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| Sandy shale | |||||||||||||||||
| Claystone | |||||||||||||||||
| Sandy limestone | |||||||||||||||||
| Soft schist | |||||||||||||||||
| 4 | Medium sandstone | Med-hard high abrasivity |
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| Siltstone | |||||||||||||||||
| Calcitic limestone | |||||||||||||||||
| Medium limestone | |||||||||||||||||
| Hard shales | |||||||||||||||||
| 5 | Hard limestone | Hard, low abrasivity |
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| Dolomitic limestone | |||||||||||||||||
| Schist | |||||||||||||||||
| Serpentine | |||||||||||||||||
| Dolomite | |||||||||||||||||
| Marble | |||||||||||||||||
| Syenite | |||||||||||||||||
| Andesite | |||||||||||||||||
| Pegmatite | |||||||||||||||||
| Hematite | |||||||||||||||||
| Magnetite | |||||||||||||||||
| 6 | Gneiss | Very hard, medium abrasivity | |||||||||||||||
| Granite | |||||||||||||||||
| Basalt | |||||||||||||||||
| Gabbro | |||||||||||||||||
| Rhyolite | |||||||||||||||||
| *** | Abrasive sandstone Pyritic formations Banded hematite Conglomerate Taconite |
Carbo- nado |
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| TC Tungsten carbide set GTS Geotechnical saw-tooth carbide set PCD Polycrystalline diamond set TSP Thermally stable polycrystalline set |
Impregnated type number: 2 for abrasive or fractured softer formations 4 for medium hard and abrasive formations 6 for hard moderately abrasive formations 8 for hard uniform non-abrasive formations 9 for hard to very hard and medium abrasive formations 10 for ultra hard non-abrasive formations |
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C.8 Core bit profiles
See Table C.17.
Table C.17 — Core bit profiles — Diamond set, impregnated, TC and PCD
| 1 |  |
Semi-round profile Profile for high penetration rate. Lower carat weight than other profiles. Standard profile for surface set thin kerf wireline drill bits. |
| 2 |  |
Full-round profile A full-round crown for thick kerf bits. |
| 3 |  |
Semi-flat profile This profile is used when coring in soft, friable or broken formation, for thin kerf bits. |
| 4 |  |
Tapert pilot profile Stronger than profile 7, but slower penetration for wireline range. Can replace profile 7 when formations are very broken. |
| 5 |  |
Pilot profile The pilot profile provides stability and directional contact for increased penetration. For thick kerf bits it helps to solve deviation problems. |
| 6 |  |
Tapered concave profile Standard profile for non-coring bits |
| 7 |  |
Multi-step profile Allows higher penetration rates than round profiles. Fragile in fractured formation, i.e. standard for surface set wireline bits. |
| 8 |  |
Concave profile Standard profile for non-coring bits. |
| 9 |  |
Pilot concave profile Used to solve deviation problems when using non-coring bits. |
| 10 a |  |
Two wide steps To be used in soft formations. |
| 10 b |  |
Two wide steps with face discharge profile To be used in soft formations with face discharge. |
| 11 |  |
W profile Standard profile for impregnated wireline bits. |
| 12 |  |
Flat profile Profile for impregnated bits. |
| 13 |  |
Sawtooth profile (side view) Sawtooth profile used mainly for Geotech bits. |
| 14 |  |
Tower profile (side view) |
| Flush alternatives CF (channel flush) standard core bit flush design ECF (expanded channel flush) Optional flush (on request) FD (face discharge flush) standard with oval holes SCAL (scallop) a combination of FD and CF NOTE Core bits with face discharge are used in loose formations where the flushing medium may destroy the core. |
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