Drives / Valves

The Beautiful Engineering of the Keystone Pipeline

Whatever Your Opinion of the Keystone Pipeline, You Have to Admire the Engineering

By Paul Studebaker

When our little company hires a new employee, we follow the usual application, resume, references and interview process, as well doing a psychological profile. But the top-level decision-makers have one more criterion they call the "train test." They ask themselves, would I want to sit next to this person on an all-day train ride.

I recently found myself on a long bus ride west from Omaha, Nebraska, with the president of Keystone Pipeline, Corey Goulet. The occasion was a press event presented by Siemens. The destination was TransCanada's Keystone Pipeline pump station near Stanton, Nebraska. The purpose was to give us a guided tour of the pump, drive and control technology of the pumping station and the pipeline, and the event included a detailed on-bus presentation of the existing Keystone and proposed Keystone XL pipelines.

Now for a brief reveal: I know that man-made greenhouse gases contribute to global warming, and that anything that makes carbon emissions cheaper and more plentiful increases the risk and problems of the following generations.

Beautiful white-enameled pipes rising out of the ground are plumbed to a row of five huge pumps, three and a half of which were humming.

Still reading? I believe we and our progeny will solve global warming, and that the Keystone XL pipeline will not make a significant difference either way.

The tour group included representatives of TransCanada and Siemens, as well as half a dozen journalists. The mid-November trip coincided with an early cold snap and snowfall. Temperatures had dropped from the 50s to single digits in a day. Slick roads led to low speeds and numerous accidents.

Goulet told us the oil moves at a "fast walking pace" through the existing 30-in. diameter pipeline, taking a couple of weeks to travel 2,200 miles from Hardisty, Alberta, to Patoka, Illinois, or Cushing, Oklahoma. Flow is kept turbulent to prevent components from dropping out or stratifying, and to keep the interfaces sharp between batches of different grades of oil.

The pipeline capacity is about 550,000 barrels per day, which you can compare to the current U.S. oil production rate of about 9 million barrels per day. The 36-in. Keystone XL offers a capacity of 700,000 barrels per day and would use a similar pumping and control architecture.

Unmanned pumping stations are located roughly every 50 miles, each with two to five 5,000- or 6,000-hp pumps, depending on the terrain. A single variable-frequency drive (VFD) is typically used to start each pump and to trim pumping capacity to match the oil grade. Operations can go on with any one pumping station off-line, and pumping stations are typically connected to different power plants. The entire system is supervised and controlled remotely from an operations center in Calgary. Local personnel can be on-site in less than an hour.

Isolation valves every mile or so can be closed to limit the amount of any leak or spill. "There's a phone number posted prominently every place a road crosses the pipeline, and we take any calls from farmers very seriously," Goulet said. Closing the valves takes a little time—even though it's moving relatively slowly, that's a lot of oil to bring to a halt.

Siemens supplied Keystone's 35 pump stations with 133 pumps, 35 control systems, 35 medium-voltage VFDs, 33 soft starters, VFD and electrical distribution shelters, and 19 substations.

About a hundred miles up U.S. 275 and a mix of state and county roads brought us to the pumping station, which occupies a couple of acres fenced out of a farmer's field. Beautiful white-enameled pipes rising out of the ground are plumbed to a row of five huge pumps, three and a half of which were humming as we donned toecaps and hard hats, and climbed out of the bus into clear, cold, biting wind.

We toured the shipping-container-sized electrical distribution enclosure (which was quite warm) where a PC-based HMI displays current operating status of the station, then walked over to the piping (which although unheated, was at about 110 F due to friction). The 6,000-hp VFD occupies its own enclosure, which we observed from afar.

As we enjoyed the equally long bus ride back to Omaha, I thought, while I'm not enthusiastic about Keystone XL, it's good to know it would be built with integrity and safeguards, and the pumping stations would be works of engineering art.

I think it would be better than putting all that oil on long train rides.