SPD WE HIPO & Lateral Learning Bulletin Location: Salym Oil Field, Well Pad 54 Slot 15, WS, ONR hoist 4 Date: 28/01/2010 What happened: During running a completion the Weatherford Power tong (JAM unit) got stuck on the pipe when making up a pup joint. After manual attempts to free the power tong from the pipe the hydraulic piston to adjust height position of power tong was used for extra vertical force. The extra force on the cable caused the bracket with sheave wheel to fail catastrophically. Bracket + wheel dropped to the floor from appr. 20 m. whilst 5 workers where on the floor. Nobody got injured. The power tong was still attached to the pipe after the incident, did not drop to the floor. • Facts: • Hoist was making use of OEM equipped brackets.Passports in place. • Outside temperature –25 ‘C. • Bracket certified to lift 3000 kg. • Weight of Power tong 1100 kg. • Bracket broke in the middle (not at weld). • Bracket and sheave wheel fell down some 20 m. • Sheave wheel was not secured by safety line. • Immediate cause: • Failure of bracket to hold force applied by piston. • Root cause: • Power tong getting stuck whilst making up pup, use of dedicated jaws. • Investigation ongoing. Manipulation of power tong (hydraulic piston) not in line • with allowable procedures • Suspect loading of bracket above rating. • Suspect material deficiencies. Learnings: • Similar construction on other hoists have been abolished (noticed deformation of brackets as well). • Installed sheave wheel with larger allowable working force + associated shackles on near-by pad-eye with larger operating envelope. • Application of secondary retention lines must be reviewed on site to ensure all potential dropped objects have secondary protection. • General rig/hoist Inspections should extend focus on possible failures.