Hydrocarbon Gas Release during Maintenance on Chemical Injection Point

Cause & Consequence

• Uncontrolled release of a flammable gas or liquid

Incident Location

Fixed Installation

Incident Activity

Maintenance

Incident Info Source

Fiona Gibson, Chevron Upstream Europe

Specific Incident Equipment

Low pressure retractable chemical injection quill.

Lessons Identified

• The blowout preventer was missing as it had not been installed on the bottom of the injection quill to stop the qull from ejecting from the packing gland body.
• The vendor procedure did not require a quill retraction tool ** to be used in standard sized systems (0.625") below 150psi. However, the equipment being serviced was once inch larger than standard size; consequently the procedure as written was not sufficient.
• The escaping gas prevented vendor personnel from reaching the double block and bleed isolation valves to stop the release. The valves were intended to isolate the injection point once the quill is retracted, but the valve handles were in a limited-access location that was no longer accessible to the vendors.

** Retraction tool - a mechanical device to help maintain control of the quill during online removal through the packing gland assembly.

Incident Recommendations

Other facilities are encouraged to consider the following issues and associated procedures when conducting maintenance on low pressure chemical injection equipment.

• Maintenance personnel should verify that the blow out preventer is correctly installed prior to reassembling the equipment.
• Maintenance procedures should be specific to the equipment being services, including when the retractor tool is necessary.
• Manual isolation valves for chemical injection points should be located where readily accessible in case of a release.