Drill collars |
 |
 Drill
collars are heavy drill string members used as weight thus forcing
the bit to penetrate the formation being drilled. The collars are
made from selected bars of chromium molybdenum alloy steel AISI
4145 H bored by trepanning to ensure close tolerance of bore alignment.
All drill collars are full length heat trated to obtain the best
physical properties and to provide a combination of hardness strength
and ductility.
Size |
O.D. (mm.) |
I.D. (mm.) |
Weight Kg./m. |
4 |
101 |
45 |
51 |
4  |
114 |
45 |
68 |
5 |
127 |
50 |
82 |
6 |
152 |
71 |
113 |
6 |
165 |
71 |
137 |
7 |
178 |
71 |
163 |
8 |
203 |
71 |
223 |
8 |
216 |
71 |
250 |
9 |
225 |
71 |
290 |
|
