Injury – A drillers assistant was disconnecting an inner tube from the overshot when the tube dropped, pinching their left hand against the drill string and causing a laceration.
In February 2025, a medically treated injury occurred at a surface drill. During a routine tube retrieval task, a driller’s assistant sustained a laceration to their left hand when the inner tube dropped, pinching it against the drill string. The injury required medical treatment, including sutures.
The incident occurred when the drillers assistant disengaged the overshot latches while they were holding the inner tube, which was still suspended on the wireline. This led to the tube dropping and pinching assistants’ hand between the butterfly pin and the end of the drill rod.
The tube retrieval process is designed to follow a controlled sequence, ensuring that the butterfly pin is inserted, and the inner tube is lowered with the wireline to a stable position on top of the drill rod before the overshot is disengaged. This method is intended to minimise the risk of unexpected movement and reduce the potential for equipment damage. Additionally, clear communication between the driller and assistant is a key aspect of the process, ensuring that each step is completed safely before progressing to the next.
The assistant had prior experience in different drilling conditions (underground), where shallow hole angles meant gravity had less impact on tube stability. This past familiarity may have contributed to the expectation that the tube would remain stable. However, in this case, the steeper angle contributed to the unexpected movement, resulting in the injury.
Use of Impact-Resistant Gloves – The highest-rated protective gloves available were in use at the time of the incident. While the drillers assistant sustained an injury in this event, it is likely that the gloves significantly reduced the severity of the injury.
Key points from this:
Secondary restraints on over shots (typically we don’t accept the butterfly pin as a secondary restraint but rather the secondary safety sling is mandated.)
Suspended loads, Take 5, Tube handling SWP etc