Tag Archives: Pipeline

Oil sands critics target a new concern – pipelines

The crude oil that is pulled from Canada’s oil sands is thick and heavy, a black tar-like substance that takes large amounts of energy and effort to make into end products like gasoline and diesel. Even some people in the Alberta energy industry describe it as “nasty” stuff.

But is it also dangerous?

Over the past few months, critics of the oil sands have taken a new tack. They are now arguing that oil sands crude, which contains more contaminants than traditional sources of crude, poses a risk to pipeline safety – and they’ve linked the recent spate of North American oil pipeline spills to what they say is the corrosive content of oil sands products.

It’s an argument that began with environmental groups, but has now been taken up by legislators. Last week, for example, Alcee Hastings, a U.S. Democratic congressman, warned that “the risk of an oil spill from these tar sands pipelines is very real.”

“The oil eats away the pipelines, compromising them and leading to frequent spills,” he said during a debate on the proposed TransCanada Corp. Keystone XL pipeline, which will bring oil sands crude to the U.S. Gulf Coast if it is approved. That echoes a February report from the Natural Resources Defense Council, an influential U.S. environmental group, which called oil sands crude a “highly corrosive, acidic, and potentially unstable” substance that “may be putting America’s public safety at risk.”

That conclusion has always been contradicted by industry, which has maintained that oil sands crude is safe. TransCanada, for example, has argued that it simply would not place at risk its $13-billion Keystone line by filling it with a dangerous substance. Yet the debate highlights the political obstacles that exist for the project, a crucial piece of infrastructure for getting the ever-rising volume of Alberta oil to market.

The two sides have left little middle ground between them. So who is right?

Interviews with academics, engineers and federal officials make clear that oil sands crude does indeed appear to pose additional risks. But those risks are largely borne by refineries that have had to deal with a dirtier and more corrosive substance than industry has been accustomed to.

In pipelines, independent sources suggest that the danger is substantially lower. Indeed, in decades past, thick bitumen was actually used to coat pipelines as protection against corrosion. And pipelines are partly shielded by the fact that they operate nearer room temperatures. Refineries, in contrast, process crude at up to 400 degrees Celsius, and the fierce heat promotes a series of chemical interactions that don’t happen at lower temperatures.

The corrosion question largely surrounds the properties of diluted bitumen, also called “dilbit.”

Oil sands producers generally produce two different products. One, “synthetic crude,” has passed through a sort of pre-refinery, called an upgrader, to transform it into a lighter substance that contains far fewer impurities. Dilbit comes from producers that don’t run upgraders. Instead, they take the oil sands crude and, with minimal processing, thin it with a lighter oil and pump it into a pipeline. As a result, it contains far higher levels of numerous noxious substances, including sulphur, acids, salts and sediments.

That in itself has raised some concerns.

Take sulphur, for example. Oil sands crude contains sulphur levels up to 10 times higher than other oil. But in dilbit, the sulphur is locked up with heavy oil molecules. As a result, it is largely harmless inside a pipeline, said Harvey Yarranton, a professor of chemical and petroleum engineering at the University of Calgary.

“You’d have to put it into reaction temperatures to release that sulphur – and those are above 300 Celsius,” he said.

Acids and salts are also found in substantially elevated levels in dilbit. But both substances are “not corrosive under pipeline conditions,” according to Natural Resources Canada, whose researchers have studied the corrosiveness of different oils. Acids need temperatures above 200 Celsius for corrosion to occur, the government said in a statement.

One area of concern remains sediments – little bits of sand that are embedded in oil. Industry measures these in pounds per 1,000 barrels. Conventional oil might measure 30 to 50 pounds per 1,000 barrels. Scott Bieber, a marketing manager with oil field services giant Baker Hughes Inc., has seen oil sands bitumen hit 500.

Sediments can contribute to corrosion in pipelines – and they have become a significant menace in refineries, where they have proven difficult to remove and help foul wastewater, Mr. Bieber said.

And environmental critics say that with the expansion in the oil sands, more study needs to be done of the effects dilbit has on pipelines. In particular, the thickness of oil sands crude – it’s far more viscous than conventional oil – creates friction inside pipelines that creates higher temperatures.

With Keystone XL, TransCanada has predicted temperatures as high as 55 Celsius. That remains far from the heat in a refinery, but higher temperatures do speed corrosion, and Anthony Swift, an energy analyst with the National Resources Defense Council, said governments both in Canada and the U.S. should take notice.

“There’s enough information out there about [the risks of] this stuff that merits a study,” he said. “The government should be protecting the public, and it’s a huge concern when they turn a blind eye to a potential danger.”

SOURCE: http://www.theglobeandmail.com/report-on-business/industry-news/energy-and-resources/oil-sands-critics-target-a-new-concern-pipelines/article2116408/

Pipeline with Coating Degradation benefit from Deep Well Anode Solution

MATCOR Mini-Deep Anode
The MATCOR Mini-Deep Anode will protect the system for 20 years or more

An International Petrochemical Company contracted with MATCOR to review assessment data gathered more than 10 years earlier.  MATCOR’s initial findings showed the existing Cathodic Protection System was struggling to maintain criteria.  To determine the exact cause of the problems MATCOR launched a comprehensive survey of 20 miles of 26 inch pipeline.

From the initial review of the pipeline, it became clear that the existing Cathodic Protection system did not have the capacity to distribute DC current effectively. MATCOR’s technicians performed Close Interval Surveys (CIS), Pipeline Current Mapping (PCM), and Direct Current Voltage Gradient (DCVG) surveys.  In addition, MATCOR took soil samples and had them analyzed, measuring pH, sulfates and sulfides, chlorides and moisture content.  The results corresponded with the smart pig runs, which further validated the testing and data analysis.  The survey revealed significant coating degradation.

It was clear from the current requirement test results that a new Cathodic Protection System was necessary.  The client’s choice was MATCOR’s patented Mini-Deep Anode System, which is very easily installed without disruption to the pipeline.

In all, 15 Mini-Deep Anodes were used to protect 40-plus miles of pipeline and connecting laterals.

MATCOR strategically placed ground beds approximately one mile east and west of the rectifiers.  On a new pipeline, each MATCOR Mini-Deep Anode can protect many miles of line, but since these pipelines experienced coating degradation, MATCOR designed the system to protect the existing lines from low structure to electrolyte potentials.

Upon completion of the testing and commissioning of the rectifier and ground bed system, this pipeline system, with associated laterals, was able to achieve -850mV OFF potential throughout its entire length.

The client was concerned that the 100mV criterion would have to be used in certain areas due to poor coating conditions; however, this was not the case.  MATCOR achieved complete integrity by incorporating the correct combination of engineering, design, and cooperation from the client.

The Mini-Deep Anodes will protect the system for 20 years or more.