Trans Alaska Pipeline System. TAPS update: new solutions keep oil flowing in aging pipeline.

• Author: Swann, Kirsten
• Position: OIL & GAS

For more than thirty-five years, the Trans Alaska Pipeline System (TAPS) has sent North Slope crude to waiting tankers in Valdez via eight hundred miles of pipe and pump stations.

Today, the giant system operates with near-perfect reliability, but orchestrating the migration of hundreds of millions of barrels of oil is no simple task. Keeping TAPS in motion depends on careful preparation and planning.

"We spend a lot of time trying to be upfront and be proactive," says Melanie Myles, oil movements director at Alyeska Pipeline Services Company.

The company that maintains TAPS on behalf of its owners performs regular maintenance shutdowns and constant system checks to monitor pipeline valves, schedule future work, and make sure problems are fixed before they occur. These days, there are several maintenance shutdowns that occur over the course of the summer, including two long-duration shutdowns that last longer than twelve hours and involve major maintenance activities, Myles says. The first took place without a hitch earlier this season, and the second was scheduled for August 21.

During the second major pipeline shutdown of the summer, crews were to replace Remote Gate Valve 40, part of Alyeska's proactive approach to maintenance that aims to head off emergencies before they occur. Even proactive maintenance takes a lot of advance preparation, Myles says.

"It's an amazing amount of upfront planning, because once you take the line down and you make that first cut, you're at the point of no return," Myles says.

Past improvements included installing new pumping units to reduce operational costs and automating the system to allow remote control of pipeline operations. An advanced supervisory control and data acquisition system allows TAPS technicians to monitor everything from pipeline valves and pressures to tank levels, temperatures, and flow rates. These days, Myles says, the company is working on different kinds of upgrades.

Right now, her top priority is to heat the line to keep the oil flowing.

Heat for Speed

As throughput declines, heat becomes increasingly important. According to data kept by Alyeska, the amount of oil moving through the pipeline fell from a daily high of more than 2.1 million barrels in January 1988 to today's average of approximately 500,000 barrels per day. As that number falls, so does pipeline flow speed, which makes it easier for particles to separate, allowing water to freeze and wax to accumulate. At roughly...