High Performance Trenchless Drilling Equipment Drill Collar
Drill collar is a component of a drill string that provides weight
on bit for drilling. This kind of trenchless tool is a thick-walled
tubular piece that is machined from a solid bar of steel, usually
plain carbon steel but sometimes of nonmagnetic nickel-copper alloy
or other nonmagnetic premium alloys. The solid bar is quenched and
tempered to obtain the required mechanical properties, then
trepanned, drifted and threaded. Located at the bottom of the drill
string, drill collar is a major component of bottom hole assembly.
The main characteristic of this trenchless tool is thick wall (It
is generally between 38 mm to 53 mm and is equivalent to 4 to 6
times of that of drill pipe), larger gravity and stiffness.
It is usually classified into spiral type, non-magnetic type and
integral drill collars. Our company is able to supply 18T-800T
drilling machines for both home and foreign drilling rig factories.
Customers can choose the most appropriate trenchless tools
according to their specific demands.
Functions of Drill Collar
In the process of well drilling, it plays an important role as
1. It provides pressure on drill bit for drilling.
2. It can guarantee the necessary strength under a certain
3. Drill collars can reduce the vibration, swinging and beating of
drill bits, making the drill bit work smoothly.
4. This type of trenchless tool can control well deflection or well
To prevent a lower drill collar from burning and for optimal usage
in straight drilling, three different
Methods can be used:
1. They can be selected that are as wide as possible and installed
in the lower section, leaving enough space between the collars and
the borehole walls to permit debris and drilling mud to pass.
2. A stabilizer or reamer may be installed in the drill collar
3. Blades can be welded to this trenchless tool so that its
diameter is nearly the same as the borehole diameter.
4. The diameter and the male and female ends of the drill collars
need to be monitored as they are more exposed to wear.