FIXED DIAMETER HOLE OPENER

1. When drilling of a big hole is not possible because of rig capacity. 

2. When a satisfied penetration rate is not obtained when drilling a big hole, it is  used after drilling is completed with a smaller bit. 

3. When the hole direction must be controlled.

● Hole size; 

● Pilot hole size; 

● Top and bottom connections;

● Fishing neck and bottom neck O.D and length; ●

 Type of cutters.