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

Away from this section By holding this section with one pipe wrench The plan was to break this sub section In this direction And rotating this section with another wrench

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 Rig (Plan)

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

Common practice

Driller holds pipe wrench in place High speed rotation is applied Drill continues to rotate and unscrew under power

Danger Zone

Drillers work in close proximity to drill string Drill String 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

This is not the first time



#1 Queensland – Chest Injury (Non URS)

 Two large chest.

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

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

hospital with chest injuries. at full speed instead of being inched. The driller was air lifted to

What can be done?

 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 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