Petroleum Pipeline Case Studies

Petroleum Pipeline Case Studies

Petroleum Pipeline, State of Washington

The Olympic Pipe Line Company, operated by BP Pipelines, North America, is a 400-mile interstate pipeline system that runs along a 299-mile corridor from Blaine, Washington to Portland, Oregon. The system transports gasoline, diesel, and jet fuel that originates at four Puget Sound refineries, and is delivered to Seattle’s Harbor Island, Seattle-Tacoma International Airport, Olympia and Vancouver, Washington, and Portland, Oregon. It is a vital component of the infrastructure in the northwest United States.

About 3:28 p.m., Pacific daylight time, on June 10, 1999, a 16-inch-diameter steel pipeline ruptured and released about 237,000 gallons of gasoline into a creek that flowed through Whatcom Falls Park in Bellingham, Washington. About 1 ½ hours after the rupture, the gasoline ignited and burned approximately 1 ½ miles along the creek. Tragically, three persons were fatally injured and more that $45 million in damages were sustained.

This important pipeline has been returned to service without further incident, but has been continuously scrutinized by numerous parties since the unfortunate accident.

In early 2007, changes were being made in the operation of the pipeline, and the consulting pipeline engineer requested the services of Pipetech International to monitor the pipeline pressure at a point near Bellingham. This monitoring would verify the hydraulic modeling of the operational changes, and would provide third-party documentation of the results for various interested parties.

The monitoring was accomplished early on a Sunday morning, and pressures recorded are shown in the graph below, covering a period of 4 hours and 45 minutes. The graph depicts steady state pressures in blue, while transient pressures are in red. Seven distinct transient events are shown:

  • Pressure is applied to the transducer
  • Flow commences
  • 1st Valve closure test
  • Pressure drop
  • Flow resumes
  • 2nd Valve closure test
  • Flow resumes

Pipetech International’s report provided accurate and complete detail of the transient pressures within the pipeline in graphic and tabular form; and served the intended purposes of informing the pipeline owner, hydraulic engineer, local officials, Office of Pipeline Safety, and the general public of the operational results.

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