Symmetric Casing System with reamer Symmetric Bit for Overburden Drilling
The Symmetric Casing Drilling system consists of three parts: central pilot bit, casing shoe and symmetrical ring bit. The central pilot bit drills away the center part of the hole and guides the drill string, incorporated with a sacrificable symetrical ring bit make a full face drill bit.
Advantages of Symmetric Drilling
Specification
Casing OD (mm) | Casing wall max (mm) | Ring bit ID (mm) | Ring Bit OD (mm) | Pilot Bit OD (mm) | Hammer |
114.3 | 6/10 | 91/78 | 128/124 | 100/92.5 | ND35 |
126.7 | 7 | 99 | 140 | 110 | ND35 |
139.7 | 7/10 | 116/94 | 154/150 | 124/117.5 | ND45/NOL4 |
168.3 | 8/12.7 | 142/121 | 182/178 | 150/140 | ND55/NQL5 |
178.3 | 10 | 145 | 195 | 156 | ND55/NQL5 |
193.7 | 6/12.7 | 167/148 | 212/203 | 180/167 | ND65/NQL6 |
219.1 | 7/12.7 | 186/167 | 234 | 203/191 | ND65/NQL6 |
273 | 8/12.7 | 232/219 | 292 | 255/246 | ND85/NQL8 |
323.9 | 8/12.7 | 281/270 | 342/342 | 306/297 | ND85/NQL8 |
406.4 | 12.7 | 328 | 419 | 374 | NSD10/N125 |
508 | 15 | 412 | 526 | 470 | ND475/SD15 |
609.6 | 15 | 513 | 637 | 570 | ND525/SD18 |