A recent council study looked at issues associated with the remote control operations of Alyeska Pipeline Service Company’s Valdez Marine Terminal. Alyeska controls some operations for the terminal and pipeline from its Operational Control Center in Anchorage.
By TOM KUCKERTZ
Project Manager for Terminal Operations
Some of the council’s concerns regarding the unknown condition of the crude oil piping at the Valdez Marine Terminal have been answered by inspections performed this summer by Alyeska.
In 2012, a routine inspection by Alyeska personnel of the 20-inch vertical riser pipes that feed crude oil to the loading arms on Berth 4 at the terminal revealed the existence of serious corrosion in some of the girth welds. Girth welds are welds that extend around the diameter of a pipe, typically used to join two sections of pipe.
Following this discovery in 2012, the remaining riser pipes on Berths 4 and 5 were subjected to additional inspections. More occurrences of vertical pipe girth weld corrosion were found and repaired. The cause of the corrosion in that particular region was attributed to water collecting under the pipe’s insulation in combination with a missing anti-corrosion paint coating in the vicinity of the girth weld.
As part of the right-of-way renewal of the grant and lease for the Trans-Alaska Pipeline System (TAPS), the Reliability Centered Maintenance (RCM) paradigm was used as the basis for assuring a thirty-year remaining lifetime for TAPS. Without a strong maintenance program for all of its assets, there can be no guarantee that the life of the assets will be 30 years or in accord with the assumptions underpinning the decision to renew the grant and lease for another thirty years. In 2004, The Joint Pipeline Office (JPO) found that Alyeska had deferred considerable amounts of maintenance that were required by regulations perhaps in anticipation of replacing assets in accordance with Alyeska’s Strategic Reconfiguration. Now that the Strategic Reconfiguration for the VMT is essentially dead, it is important that all maintenance deferred pending a successful Strategic Reconfiguration be completed according to the schedule required by regulation.
This project seeks to verify that the maintenance required of each facility and subsystem at the VMT of concern to PWSRCAC has been identified by means of an RCM process. Additionally, this project seeks to verify that maintenance of VMT facilities is being accomplished in accordance with the dictates of the RCM reports produced for each of the VMT’s facilities and subsystems.
Because better seismic engineering is now available for asset protection and because the 1964 earthquake is now believed to have been more severe than originally thought, the council is concerned that the seismic protection of Valdez Marine Terminal (VMT) assets may not be adequate for an earthquake of the size that occurred in 1964.
Specific concerns are the stability of containment dikes around the various types of storage tanks, slope stability, stability of earth and rock support under storage tanks, and the structural integrity of all oil handling components of the VMT, especially those weakened by corrosion.
- identify extent to which VMT may not satisfy current seismic engineering standards
- examine seismic re-engineering issues at the VMT
- recommend feasible seismic re-engineering activities for the VMT
- identify current risks of significant oil spills due to large earthquakes at or near the VMT
- coordinate with other seismic studies being conducted in Alaska
- identify if degradation of physical plant has lessened its capability to withstand earthquakes
The Joint Pipeline Office (JPO) has indicated to Alyeska that the seismic standards to which Alyeska structures and facilities must conform are those described in IBC 2003 (International Building Code -2003). It is expected that those facilities and structures not presently conforming may be fully or partially grandfathered to older standards.
Seismic Reengineering VMT (3.2 MB)
Rock Slope Stability VMT (1.7 MB)