Drill Collars 4.125inch 4.75inch
Non-Magnetic Drill Collars
Command Tubular’s non-magnetic drill collars are an integral heavy
duty joint that are constructed from a solid bar of austenitic
stainless steel. Our non-magnetic drill collars are supplied with a
machined surface finish condition.
All non-magnetic collars are hot/cold worked in order to provide
them with the necessary mechanical properties. The bars are then
trepanned, hot spot inspected and machined. An internal bore
treatment is performed on the full length in order to achieve the
proper compressive status of the internal diameter.
This provides the collar with optimal resistance to stress
corrosion cracking. All of our drill collars are manufactured in
accordance with API spec 7, Q1 and recommended practice 7G as
applicable.
Spiral Drill Collars
The spiral cut is added to a drill collar to prevent the likelihood
of differential wall-sticking by reducing wall contact between the
drill collar and the wall of the hole. The spiralling starts 22”
from the bottom of the slip recess or 79” from the box end and ends
30” from the pin end. Adding spiralling to drill collars reduces
the weight by approximately 4%.
Short nonmagnetic drill collars (SNMDCs):
SNMDCs are used between a mud motor and a mud collar to neutralize
magnetic interference from the following.
Connections
All connections are precision-machined to API Spec 7-2
requirements. API relief groove pin and bore back box stress relief
are available on request. Thread roots are cold-worked to offer a
greater resistance to fatigue. At Command Tubular all connections
are phosphate coated to minimize galling during makeup and thread
storage compound is applied. Thread protectors are installed to
ensure adequate joint protection during shipment.
Drill Collars in Drilling Application
Drill collars play a vital role in drilling process. Due to the
structural features, drill collars can provide weight for drilling
purpose, which is drill collar’s one and foremost specialty.
Gravity works on a number of drill collars to offer enough downward
force needed to break rocks with the drill bit.
Apart from providing weight on the bit (WOB), drill collars also
work as a shock absorber to dampen the vibration and shaking when
drilling takes place. In this way, the drilling process can be
carried out in a much steadier state.
Thirdly, the presence of the drill collars allows the pipelines to
stay in the tensile state, while guarantees the rigidity of the
drill string under great compression. Thus, the drill efficiency
and quality are greatly improved.
In addition to the above applications, drill collars can help to
control the direction of the bottom hole assembly, avoiding the
problem of hole deviation and enhancing the performance of
drilling.
For more information please contact:
Skype: ROSCHEN.TOOL , ROSCHEN_GROUP
WeChat: +86-137 6419 5009 ; +86-135 8585 5390
WhatsApp: +86-137 6419 5009 ; +86-135 8585 5390
Email: roschen@roschen.com ; roschen@roschen.net
Website: http://www.roschen.com ; http://www.roschen.net
