Drilling Contractor Safety Understanding the hazards associated with rod separation.
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Transcript of Drilling Contractor Safety Understanding the hazards associated with rod separation.
Drilling Contractor Safety
Understanding the hazards associated with rod separation
An Incident
NZ September 8 2006 two drilling contractors were using pipe wrenches to separate drill rods that were extremely tight.
During this process, the hydraulic rotation of the drill string was accidentally activated
Both men were hit by the handle of a pipe wrench and knocked to the ground.
Both men suffered severe bruising.
It could have been much worse
What Went Wrong?
Mechanical tools for rod separation were available but were not used
The drillers decided to separate the rods using manual tools
The hydraulic controls were not protected from inadvertent operation
Hydraulic rotation was accidentally applied
The plan was to break this sub
sectionAway from this
section
By holding this section with one
pipe wrench
And rotating this section with another
wrench
In this direction
With the wrench in place the drill is rotated slowly anti-
clockwise to apply tension to the wrench by bringing the
handle of the wrench against the mast of the rig
Drill string rotation is
stopped but hydraulic
power remains
Drillers work in close proximity to drill string
Drillers attach pipe wrench to secure one section of the
drill string
Rotation is accidentally applied
Drill Rig (Plan)
Common practice
Drill continues to rotate and unscrew under
power
Driller holds pipe wrench in
place
High speed rotation is
applied
Drill String
Drillers work in close proximity to drill string
Danger Zone
Danger Zone while drilling
Add a pipe wrench and area increases
significanlty
A rotating pipe wrench – Easily makes contact with anyone near the controls. Maximum speed. ~1,000rpm
Why is this a major issue?
The combination of manual tools with hydraulic rotation identified as a major contributing factor
The practice is common and widespread There is an alarming history of similar incidents
from a number of industries where drill rigs are used
The following examples did not occur on URS projects
#1 Queensland – Chest Injury (Non URS) Two large pipe wrenches were used in
conjunction with a lever block to disassemble a hammer bit on a drill rig string. The handle of the wrench broke striking the drilling operator in the chest.
This is not the first time
#2 Western Australia – Chest Injury (Non URS) A driller was struck in the chest by the
handle of a pipe wrench when rotation was released following torguing up of a joint.
This is not the first time
#3 NSW – Head injury (Non URS) Two field technicians were hit on the head
by a drill rod which was being used as a pipe wrench extension handle to break drill rods
This is not the first time
#4 Western Australia – Broken Legs (Non URS) A driller received two broken legs when
rotation was applied to the drill rods with a pipe wrench attached
This is not the first time
#5 Western Australia – Abdominal Injury (Non URS) A driller received serious injuries to the
abdomen when hit with the handle of a pipe wrench
This is not the first time
#6 Pennsylvania USA – Broken Ribs (Non URS) A drillers is hit in the chest with the handle
of a pipe wrench which was attached to a drill string. The drill was rotated at full speed instead of being inched. The driller was air lifted to hospital with chest injuries.
This is not the first time
Where practicable, use mechanical means of drill rod separation (only) at all times
Where mechanical methods of rod separation are not suitable or available, eliminate the combination of manual tools with powered rotation.
Whenever manual pipe wrenches or hand tools are used to fit or remove drill rods, this must only be undertaken once the rotational power of the drill string is isolated, de-energized or positively disengaged such that intentional or accidental rotation of the drill string while pipe wrenches or tools are attached is not possible
What can be done?
What is mechanical means of drill rod separation?
Opposing Hydraulic Control
Rod Locking Devices
Rod Spanner
Hydraulic foot clamp
Hydraulic Break-out Tool
What is manual rod separation?
The use of manual hand tools (pipe wrenches) to lock or separate rods
When should you this method be used?
Only when the rotational power of the drill string is isolated, de-energized or
positively disengaged