Cause & Consequence
- Uncontrolled release of a flammable gas or liquid
Incident Info Source
Fiona Gibson, Chevron Upstream Europe
Specific Incident Equipment
Low pressure retractable chemical injection quill.
- 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.
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.