Rig AD-48 Substructure Raising Cylinder Failure (ODS)

Oct, 2021 on AD-48, the operation was raising sub-base via 2 hydraulic cylinders. After raising it to approximately 50 %, the hydraulic manifold of the ODS mast raising cylinder failed which led to the loss of hydraulic oil. The cylinder rested back to its initial position while the cylinder on DS held in place due to activation of its safety check-valve. The substructure & mast leaned towards the ODS. No personnel were injured and there was only property damage. Stopped all rig-up

activities after the event. Rig recovery & incident investigation are currently ongoing.

• Operation suspended immediately and held safety stand down.
• Assessment of the situation and planning for the further action is in progress.
• Areas around the MAST is fully secured and all entries to the location are restricted
• Joint investigation is ongoing by ADC and Saudi Aramco.
• Alert all ADC rigs across the fleet that use these cylinders to ensure that their cylinders are certified as well as visual inspection is carded out prior to each use.

• Operation suspended immediately and held safety stand down.
• Assessment of the situation and planning for the further action is in progress.
• Areas around the MAST is fully secured and all entries to the location are restricted
• Joint investigation is ongoing by ADC and Saudi Aramco.
• Alert all ADC rigs across the fleet that use these cylinders to ensure that their cylinders are certified as well as visual inspection is carded out prior to each use.