Pacific Gas & Electric Company (PG&E) works every day to safely transport natural gas through its 6,600 miles of transmission and 42,000 miles of distribution pipelines. As part of that effort, the company has implemented a pipeline modernization program to ensure that its pipelines are up to the task.
Recently, the utility undertook its L-402 program in Northern California. The program involved integrity testing, as well as valve automation and the installation of launcher/receiver stations to facilitate the use of inline inspection tooling (smart pigs) that will help the utility efficiently manage its network in the future.
In order to perform the work, the gas lines needed to be taken out of service. Yet, on this particular program, near Redding, California, all the work was performed off a single 38-mile-long lateral feed, meaning that the only way to keep gas flowing to customers, was to inject gas via tanker trucks downstream of the out-of-service pipes.
In total, the L-402 program required the injection of more than 1.35 million gallons of LNG over 19 days, all transported by trucks, each on a 30-hour round trip. At peak, the contractor, Barnard Pipeline Inc., employed more than 200 craft employees with an additional 50 subcontracted employees.
“This is reportedly the largest LNG/CNG outage undertaken in the North America,” said Shane Medley, project manager for Barnard. “It may not have been a huge project in terms of the pipe size (8-, 10- and 12-in.), but the planning and preparation needed to complete the project while not impacting customers was extremely difficult.”
PG&E and the Barnard team estimate that this complex program required over 1.5 million man-hours from design, construction, inspection, gas control, management, and vendors and suppliers. Remarkably, the program finished with zero at fault dig-ins or line strikes, and zero OSHA recordable incidents. The team also received numerous customer appreciation notices.
Since 2013, Barnard has participated in PG&E’s Natural Gas Pipeline Modernization Program dedicated to strengthening and improving the integrity and safety of its natural gas transmission system in Northern California. A project within this program, L-402 included 12 contracts comprised of five valve automations, one inline inspection site, and two hydrotest sections, all spread across 38 miles of single-feed lateral transmission pipeline.
To complete this work, Barnard conducted 24 strength tests, automated 8 valves, and safely completed over 100 challenging excavations involving wet and “in the street” conditions. The project began in early March 2016 and reached substantial completion in mid-October 2016.
As with many multi-jurisdictional projects, communication with all stakeholders posed the greatest challenge. The project team, staffed with ample management, communicated daily at a foreman’s meeting an hour before crews arrived and nightly during an end-of-shift conference call to create the next day’s plan. Every evening, the team sent a document to construction management, environmental representatives, customer impacts, water specialists, land agents, inspection groups, X-ray, and project management. This document kept all stakeholders apprised of the plan and the crews’ locations for the following work day.
Barnard elected to self-perform the scheduling task, based on the belief that the team who knows the schedule best knows the project best.
Scheduling presented a challenge with many moving parts and hard deadlines. The team used Asta Powerproject to manage the macro-schedule and a web-based program to manage the micro-schedule. The micro-schedule included clearance schedules, traffic control schedules, hydrotest schedules, restoration schedules, and more.
From a permitting and regulation standpoint, the team encountered many obstacles. The project required multiple stormwater pollution prevention plans (SWPPPs), and often soil and water could not be treated the same from one excavation to the next. The team handled work-hour restrictions at many locations for various reasons, including schools, businesses and total overall hours allowed to limit impact in an area.
Barnard’s subcontractors included: Rader Excavating, Inc., Machado and Sons Inc., Material Testing Inc., Lonestar West Hydrovac, and Badger Daylighting Corp.
As a prime contractor, Barnard had the risk of selecting solid, efficient, reliable and affordable subcontractors, who integrate with the Barnard team. Barnard trained subcontractors through the PG&E required Veriforce courses. This effort brought everyone together to work toward the common goals of improving the community’s safety and making PG&E one of the safest and most reliable utilities in the nation.
All of the subcontractors provided excellent service with great communication on scheduling and performance. The challenging program was completed without encountering disputes that couldn’t be resolved by a simple phone call or face-to-face conversation. This added great benefits to the contractor team’s success, which in turn made PG&E successful in the community.
Interestingly, the project was unique for PG&E in that it combined work groups – hydrotesting/strength testing, valve automation, and inline inspection – that typically operate independently.
“To get these workstreams to work together, along with all the contractor team members, government entities, customers, etc., was a tremendous feat,” Medley said. “Everyone knew the urgency and importance of completing this project, and we were all focused on completing a common goal.”
PG&E selected Barnard as one of four alliance partners in a movement to become the safest, most reliable utility in the nation. L-402 is all about integrity of the natural gas system, and most importantly, safety of the community. With these improvements, PG&E can confidently say that its system meets the current standards mandated by the California Public Utilities Commission (CPUC) and will provide years of safe natural gas delivery to its customers.
All of the valve automation and inline inspection sites Barnard constructed for the L-402 Program add to PG&E’s overall vision of an easily testable and improved state-of-the-art gas control system. By making the line pigable, PG&E can monitor the integrity of the pipeline via smart pig runs without having to repeat the major outage performed in this program. With the valve automation, PG&E can operate the mainline valves via Gas Control centers.
Barnard joined the program in the pre-construction phase and provided many man-hours of constructability review. Barnard attended meetings with project management, engineering, construction management, environmental specialists, land agents, and city, county and state officials. This effort built an integrated team from Day 1 that was a key component to the project’s success.
“Barnard’s ability to realize efficiencies in scale on this challenging and dynamic hydrotest project made the project a success,” wrote a PG&E Northern Region construction manager. “Without their direct participation and partnering, PG&E would not have been able to address the Integrity Management Flags on the L-402 pipeline.”