Significant HCR from xmas tree adaptor flange

Cause & Consequence

• Uncontrolled release of a flammable gas or liquid

Incident Location

Fixed Installation

Incident Activity

Production operations

Specific Incident Equipment

Wellhead

Lessons Identified

• The importance of verifying integrity of equipment by inspection and leak testing after equipment is installed, even if the equipment supplier provides suitable and sufficient documentation in the relation to the equipment factory testing.

Incident Recommendations

• Replace gasket and torque flange to correct settings supplied by OEM. Check all other bolting on tree to ensure torque settings correspond with those supplied by OEM. Undertake pressure test of the tree.
• Review and update xmas tree commissioning procedure to ensure suitable and sufficient commissioning / pre-use checks are carried out which includes site pressure testing and bolt torque certification.
• Conduct a study to identify an improved method of physically identifying fastenings/flange torque status.
• Ensure all relevant personnel are briefed on incident and the importance of tracking equipment and following materials management procedures.
• Update Leak Testing, Service Testing and Inert Gas Purging Procedure to include section on N2/He leak test on Xmas Tree boundary prior to production start-up.