Most of the maintenance activities we undertake to keep the Trans Mountain pipeline system operating safely can occur at the same time as shipping operations. But occasionally, we shut the pipeline down for a sustained period — usually 36-48 hours. These shutdowns take place about twice per year and require extensive pre-planning. They allow our crews and contractors, working in shifts around the clock, to carry out projects providing key enhancements to our infrastructure such as installation of a new valve on our mainline.

Our most recent shutdown took place in June 2019. We connected with Paul Huddleston, Vice President, Engineering and Tech Services, to learn more.

What projects were carried out during the shutdown?

During the June shutdown, the critical path project was the tie-in of a new 30-inch check valve at Kilometre Post 918 (Pine Pit, near Merritt, BC). Check valves automatically prevent backflow and reduce the volume of oil released in the unlikely event of a pipeline spill or rupture, and are installed at key locations such as an environmentally sensitive area. We had 45 personnel working at this site, including both day and night shifts.

Nitrogen is pumped into the mainline to push a “purger pig” down the line and drain pipe across the work site. This creates a safe work environment for workers to install the new check valve.

The other significant project was tie-in of a new booster pump at the Sumas Terminal where we had approximately 40 people working.

In addition to these projects, maintenance and testing work was completed at 14 other sites during the 48-hour shutdown.

Following “blow down” (depressurization of the pipe – the pipe is pressured up as part of the nitrogen purge), crews cut out a section of pipe to make room for the new check valve. This photo depicts the typical interior condition of the mainline following a nitrogen purge.

What sort of planning, coordination and teamwork does it take to get a project like this done?  

It takes an enormous effort behind the scenes to prepare for shutdown projects. This workload is shared amongst the field engineering group, field operations and maintenance personnel, as well as a large number of third-party service providers. Support is also provided by employees and contractors based in the Calgary office.

The coordination and scheduling of activities at the various sites is orchestrated by Cory Benoit who maintains the shutdown schedule and collaborates between the various project managers and the Shipper Services group to schedule outages. Careful planning and execution are needed with Scheduling and with the Control Centre to stage batches and launch pigs for pipeline purges.

The cut-out section of pipe is removed from the ditch and stored on the side for testing by Trans Mountains integrity department.

All the steps required to carry out the complex pipeline cutout jobs are detailed in job plans written by the engineers responsible for each particular job. Job plans follow a documented standard, are reviewed and approved by Raj Lalli, Manager Field Engineering, and are used to guide job hazard assessments before starting work.

Once the pipe has been removed, vapour barriers (mud plugs) are installed on the existing mainline and welders perform field cuts to ensure that the check valve will properly fit.

Work continues 24/7 during shutdowns to minimize loss of throughput. Shifts are planned in advance with relief for each role to ensure all personnel get sufficient rest time before returning to work. 

Our workforce has a fantastic track record for safely completing difficult jobs in a short time frame. The planning processes we follow were developed over the course of many years and continue to be improved.

Heavy equipment is utilized to bring the new check valve into position. Equipment is required on both sides of the cut-out to allow for manipulation of the pipe and get proper fit-up.

How does it feel when the work is complete and the pipeline’s running again? 

I feel very proud to be part of an organization that can consistently plan and execute complex projects safely and within such short time frames. It reinforces my belief that our employees and contractor resources are second to none and are ready to respond to challenges should they arise during operations.