NAGREP PG&E Interface Project

In 2014, a natural gas transmission/distribution company determined that their primary natural gas supply pipeline, to a major oil and gas refinery, had the potential of being shut down for an extended period of time as a result of pipeline integrity issues. The shutdown of natural gas supply would immediately result in an extended shut down of that major US refinery. As a result of this risk, the refinery initiated a project to develop a mitigation plan that would provide the refinery with an alternative natural gas supply. Total natural gas consumption at the refinery ranged from 120 MMSCFD to 200 MMSCFD.

This $16 million project required natural gas supply improvements two (2) facilities. The first facility improvement would involve the connection of an existing 18-inch natural gas pipeline, owned by the refinery, to a second source of natural gas where natural gas reliability was much greater. The second facility improvement would involve the installation of a new pressure regulation station (connection to the 18-inch pipeline above), three (3) 16-inch parallel meter runs, and an automated piping manifold to distribute natural gas to the refinery from two sources of natural gas. The automation of the natural gas distribution manifold involved the detection natural gas supply issues (loss of pressure – caused by any number of reasons) from either of the two supply pipelines, and the automatic actuation of valves to mitigate the loss of natural gas. The actuation of the manifold valves, to align the refinery processing units to the pipeline with continued integrity, would prevent a refinery wide shut down.

NAGREP Project

EDM’s experience with system hydraulic modeling, and pipeline automation systems, allowed us to define a workable solution for the refinery to improve natural gas reliability into the plant. We were able to model the interaction between the two large volume natural gas supply pipelines, and the refinery’s processing units (gas consumption points). This allowed us to engineer an automated natural gas distribution system to prevent a refinery shut down in the event of a pipeline failure. Beyond the process design, our vast experience with mechanical, structural, civil, electrical, and controls engineering allowed us to execute the entire project engineering work scope. Beyond the challenge of providing a reliable natural gas supply, the project site required complex deep foundations, work within an environmentally sensitive area, coordination with multiple third parties, and other challenges.
EDM Services was responsible for all aspects of engineering management, front end engineering, project planning, process design, hydraulic modeling and simulations, detailed engineering, and as-built completion drawing preparation for the work at both sites. Our total engineering fees for this project were $730,000 (4.5% of project cost).