Reconfiguration work on the trans-Alaska oil pipeline began last summer during scheduled maintenance shutdowns of the pipeline and that work is continuing and will wrap up in mid-2006 when the new equipment is brought online.
Two things will be accomplished: the pipeline will be right-sized to its present throughput of about a million barrels a day, half of its peak 1980’s throughput, and operating efficiencies will be gained through installation of modern, more efficient, equipment.
Equipment that is being replaced is some 30 years old, Ian Livett, Alyeska Pipeline Service Co.’s pipeline reconfiguration project manager, told Petroleum News May 11: It’s high-maintenance and is becoming obsolete.
In addition to being more efficient the new equipment is “a lot more highly automated … because we’re taking advantage of automation capabilities that didn’t exist 30 years ago.” The new equipment is generally smaller and fits into truckable modules, he said. The 58 modules being build now include control modules, pump station control modules, power distribution control modules, pump modules and diesel generation modules.
Module construction is under way in Anchorage and pilings for the modules are being installed at four pump stations along the pipeline.
The work includes the $250 million work at pump stations 1, 3, 4 and 9 approved last year, and with additional work along the pipeline the total will be in the $250 million to $300 million range, Livett said.
Alyeska also is working on plans to reconfigure the Valdez Marine Terminal to modernize and size it for present throughput.
Design modular and scaleable
The design is both modular and scaleable: Alyeska will be able to downsize or upsize as needed in the future, Livett said.
Contracts have been let for 58 truckable modules, plus access platforms and skids. “All those modules are in various stages of construction” in Anchorage, Livett said. In addition to the truckable modules, five large power generation buildings will be built at the pump stations, basically arctic enclosures to protect equipment and workers in Alaska’s harsh environment. Turbine generators for power generation are complete and are being shipped to Anchorage and will arrive in June for installation at the pump stations.
A lot of existing buildings at pump stations 1, 3, 4 and 9 will no longer be used, although some structures, such as manifold buildings where the pipeline comes into the pump station will stay in service “and we tie the new facilities into those buildings,” Livett said.
There are four remaining pump stations and a relief station which doesn’t have pumping capabilities.
It takes three pump stations (1, 3 and 4) to get the oil to the top of the Brooks Range, with pumps pressurizing the oil at each station. Only one additional pump station, number 9, is needed to get the oil the rest of the way, because it’s pretty much downhill from Atigun Pass at the top of the Brooks Range. Pump station 5 at the bottom of the Brooks Range is a relief station, Livett said, with tankage to store oil in the event of a pipeline upset.
Pump stations 3 and 4 are very remote, between the North Slope and the Brooks Range, and Alyeska will continue to generate its own power at those stations, using natural gas coming off the North Slope in an eight-inch pipeline, but with new turbine generators.
At pump station 9, in Delta Junction, Alyeska will hook into the existing Golden Valley Electric Association power grid. “Today we have to haul diesel from the North Pole refinery to pump station 9 every day,” he said. Hooking into the Golden Valley grid eliminates the cost of hauling diesel, as well as the potential for spills and the possibility of accidents on the highway.
At pump station 1, on the North Slope, Alyeska is tying into the electricity grid at Prudhoe Bay, although it is keeping a power generation package at that station.
There is no electric grid at pump station 5 on the southern side of the Brooks Range, and no natural gas. Diesel will continue to be hauled to that station, but the new diesel power generators are much more efficient, so a lot less diesel will be needed.
Having less equipment and more efficient equipment will reduce air emissions by more than 50 percent Livett said.
Alyeska Pipeline spokesman Mike Heatwole said reduction in transfer of liquid fuel is the other key environmental benefit of the pipeline reconfiguration, because fuel transfer is where the company has a lot of its smaller spills.
Automation and condition monitoring
New equipment is only part of the story.
That new equipment will be connected to a new SCADA, system control and data acquisition, Livett said.
The reconfigured pipeline will be “totally remotely controlled,” initially from the existing operations center in Valdez, but eventually from a new operations center in Anchorage, with no operators needed in the field.
“And that is how just about every other pipeline in the world operates,” he said.
In addition to remotely controlling the pipeline, the new system will remotely monitor, “constantly acquiring performance data for all of the new equipment.”
This allows a change in maintenance from “reactive, fix it as soon as it breaks” to “proactive, planned maintenance.” And it allows maintenance to be centralized, replacing maintenance shops at each pump station which are staffed to react to problems.
“You couldn’t have even conceived of doing this 30 years ago,” Livett said. Because of the computing capabilities available today, “condition monitoring” will be available for all the new equipment “and our maintenance folks will be able to plug into that and figure out what’s going on and proactively maintain in the future.”
Moving toward mid-2006
Field work began last summer. Module construction began over the winter and continues. And foundation piles, more than a thousand, are being installed now for the new equipment. Modules and platforms will be shipped to the pump stations over the summer, “and we want to install as much as we can outside this summer before the weather deteriorates,” Livett said. In October and November, work will move inside. That is “mostly control system upgrades” including upgrading all of the fire and gas systems to current technology, making facilities safer. That will involve fairly limited crews over the winter.
Next spring work will move back outside. The interconnecting work between the new facilities and the existing facilities will be finished, followed by functional checkouts of new equipment, followed by commissioning.
The functional checkout and commissioning will be done as the old system runs, “so one of our big challenges is to do all this and not impact the existing operation,” Livett said.
The commissioning work will be finished sometime in mid-2006, and then Alyeska will switch from the old facilities to the new. No problems are anticipated, but if any occur, “the system is designed to allow us to revert back to the existing system,” Livett said.
