Safety Learning: Could This Happen in Your OC? Anadarko, Dropped Blocks June 2, 2009

1. Safety Learning: Could This Happen in Your OC?Anadarko,Dropped Blocks June 2, 2009 Brief Description: A well servicing pole unit was on the Wayne Cleveland “C” 5 to change out the wellhead. At 1730 hrs the job task was completed and the crew began the rig down process to move to the next well location. The guy wires were disconnected and the upper pole section was scoped into the lower pole section. Then the traveling block hook was connected to the eye hook located on the lower pole section and the drill line pulled tight. The tension caused the eye hook to fail due to metal fatigue. The operation was suspended to develop a plan to lower the pole. A decision was made to use a chain to attach the traveling block hook. The drill line was pulled tight to break the pole over from its vertical position. The winch line was then used to control the descent of the pole as it’s lowered to the headache rack. At the same time, while maintaining tension, the drill line slack must be taken out as the pole is lowered. This tension prevents the upper pole section from scoping out as the pole is lowered. When the pole was approximately 1’ away from the headache rack, the chain used to secure the traveling block failed unexpectedly. The pole slowly descended to the headache rack due to the winch line moving through the cable pulley system. Due to the release of tension on the drill line the upper pole section scoped out approximately 1.5’. This caused the traveling blocks to move forward. The Driller observed the situation and stepped away from the Operator controls as the traveling blocks fell from its road position. The traveling blocks rolled off the pole, struck the base of the carrier, and finally came to rest on the ground next to the service unit. As discussed, personnel observed the buffer zone and were not in harms way of the dropped blocks. 1 • Lessons Learned: • This was the first time that the operator had rigged down using double sheave deadline (usually operates on double line). • Operator was using too low of a gear for this operation – second gear, high - which significantly increased the amount of pulling force. • Inadequate rig down procedure. Procedure lacked detail of what gear should be used when rigged up on double sheave deadline. • Chain should not have been used as an attachment point to secure block assembly • Establishing a secure buffer zone eliminated the risk of injury to personnel Damaged eye hook and chain Road position of blocks Upper pole section scoped out 1.5’ Damaged control panel cover 3 2 Operator position at controls Traveling block assembly Fall path