Diluted bitumen, heavy crudes are similar, NAS panel told

Diluted bitumen (dilbit) from Alberta’s oil sands is so similar to heavy crude oils, which US pipelines have handled for years, that it is unlikely to pose corrosion problems, experts told a National Academies of Science panel on July 23. “Once processed, dilbit is simply oil,” said Peter T. Lidiak, pipelines director at the American Petroleum Institute. “It’s made of the same components in any mixture of crudes.”

Crude from Canada’s oil sands has been delivered to US refiners by pipeline since 1968, he told the committee studying pipeline transportation of dilbit at the request of the US Pipeline and Hazardous Materials Safety Administration. Tariff specifications from the US Federal Energy Regulatory Commission limit impurities in pipeline crude, including total water and solids, which must be less than 0.5%, Lidiak said.

“Pipelines are high-value assets intended for operation over many years,” he added. “Operators have no incentive to accept shipments which could damage their systems.”

John Zhou, of Alberta Innovates Energy and Environment Solutions, part of the provincial government’s technology arm, said the group’s comparison of sour crudes and dilbits found no significant differences, although solids in both instances need to be better characterized.

“For me, dilbit is just another crude,” said Oliver Moghissi, president of NACE International in Houston and director of the materials and corrosion technology center at DNV Columbus (Ohio) Inc. “We just put back into it some of what comes from other crudes.”

Sources of problems

Problems mainly arise when water that has not been removed from a crude before it goes into a pipeline begins to separate and collects at points along the bottom of the pipe’s interior, he explained. Dissolved gases—primarily carbon dioxide—and oil extracts such as organic acids also can influence corrosion rates, Moghissi said. Running a pig through the pipeline probably is the most effective corrosion inhibiter, although chemicals also can help, he told the panel.

“For new pipelines, design, manufacturing, and construction will be more important than preventing internal corrosion in preventing releases,” Moghissi said. “It’s also important to sample under live conditions. You can’t do it in a tea cup or mayonnaise jar because the atmosphere will have changed.”

But Jeffery Gilliam, PHMSA’s engineering and research director, said the US Department of Transportation agency concentrated on internal corrosion because it’s the single most likely risk factor since it involves the interaction of a transmitted product on the pipeline’s interior.

Although concern has been expressed about possible problems from pipelines shipping crudes that may be more corrosive because they contain abrasives, lines transmitting dilbits have had only nine corrosion incidents in the last 10 years, he told the NAS committee. Naphtha normally is used as a diluting agent, although gas condensates and similar light products also work, Gilliam said.

“As a starting point, the committee might want to reference similar types of crudes,” suggested Linda Daugherty, PHMSA’s deputy associate administrator for policy and programs. “Age also is a definite factor. Many pipelines were installed 40 years ago and have sharp turns where water which has separated from dilbit would tend to collect and start corrosion.”

Operators’ strategies

Officials from two pipeline companies that ship Canadian crude to US refineries also said preventing water accumulation is the major weapon against interior corrosion. Both Canada’s National Energy and FERC in the US limit allowable sediment and water to 0.5%, according to Scott Ironside, Enbridge Inc.’s integrity programs director. The pipeline firm regularly runs pigs where its lines are susceptible to water or solids accumulation, he said. “Enbridge has never had a release caused by internal corrosion on its piggable pipelines,” he reported.

“US refineries can handle heavy, sour crude we’re shipping from Canada because they’ve been handling it from Venezuela and California for years,” maintained Jenny Breen, who helped Alberta Innovates conduct its study before joining TransCanada Corp. as a pipe integrity corrosion specialist 6 weeks ago. Fully turbulent dilbit flow will prevent suspension of sediment and water, she said.

Bruce Dupuis, TransCanada’s liquid pipeline integrity manager, said the carrier ships multiple crude grades in 100,000 bbl minimum batches on its existing Keystone pipeline from Hardesty, Alta., to US refineries. “We sample every batch that comes into our system, and begin prerequisite testing when one doesn’t meet our specifications,” he said. “We’re also seeing the velocity products travel basically clean the line.”

But Anthony Swift, an attorney in the Natural Resources Defense Council’s international program, urged the committee to question assurances that dilbit is so similar to sour crudes that it won’t cause additional problems for pipelines. He also criticized PHMSA’s decision to emphasize corrosion, noting that poor planning and response were bigger culprits when crude oil leaked from a rupture in an Enbridge crude pipeline near Kalamazoo, Mich., in 2010.

Swift also questioned comparisons of dilbit to imported sour crudes that are partially refined at their ports of entry before entering pipelines; to California heavy crude because it travels a much shorter distance to specially configured refineries than dilbit moving through TransCanada’s proposed Keystone XL pipeline would; and to Canadian synthetic crudes produced since the 1960s that were upgraded near mine mouths.

“It would be better to compare dilbit to lighter crudes which historically have been shipped on US pipelines,” he said. “The argument that this is similar to conventional crudes doesn’t bear out. There are major hydrocarbon differences.”

Contact Nick Snow at nicks@pennwell.com.

Related Articles

NCOC lets $1.8-billion pipeline contract for Kashagan field

02/06/2015 North Caspian Operating Co. (NCOC) has let a $1.8-billion engineering and construction contract to ERSAI Caspian Contractor LLC, a subsidiary of Sa...

AOPL releases 2015 safety performance and strategic planning report

02/06/2015 The Association of Oil Pipe Lines is committed to further improvements despite a 99.99% safe petroleum liquids delivery rate, AOPL Pres. and Chief ...

PAA to expand Delaware basin crude pipeline systems

02/05/2015 Plains All American Pipeline LP (PAA) plans to build two Delaware basin crude oil pipelines and related gathering systems, to expand its existing B...

Alberta’s premier seeks more North American energy integration

02/05/2015 Better policy integration and cooperation will be needed for Canada, Mexico, and the US to fully realize the North American energy renaissance’s po...

Oil, gas infrastructure investments essential, House panel told

02/04/2015 Investments in oil and gas transportation and storage should move ahead because they are essential in continuing the US economic recovery and North...

Inpex starts development drilling at Ichthys field

02/04/2015

Inpex Corp. has started development drilling in Ichthys gas-condensate field in the Browse basin, about 200 km offshore Western Australia.

BG’s 2015 budget ‘significantly lower than 2014’

02/03/2015 BG Group plans capital expenditures on a cash basis of $6-7 billion in 2015, a range it says is “significantly lower than 2014” due to “a lower oil...

Live Oak LNG to build Calcasieu Ship Channel liquefaction, export site

02/03/2015 Live Oak LNG LLC, a subsidiary of Parallax Energy LLC, Houston, will invest $2 billion to develop a 5-million tonne/year liquefaction plant and LNG...

EPA suggests DOS reconsider Keystone XL climate impact conclusions

02/03/2015 The US Department of State might want to reconsider its conclusions regarding potential climate impacts from the proposed Keystone XL crude oil pip...
White Papers

Pipeline Integrity: Best Practices to Prevent, Detect, and Mitigate Commodity Releases

Commodity releases can have catastrophic consequences, so ensuring pipeline integrity is crucial for p...
Sponsored by

AVEVA’s Digital Asset Approach - Defining a new era of collaboration in capital projects and asset operations

There is constant, intensive change in the capital projects and asset life cycle management. New chall...
Sponsored by

Transforming the Oil and Gas Industry with EPPM

With budgets in the billions, timelines spanning years, and life cycles extending over decades, oil an...
Sponsored by

Asset Decommissioning in Oil & Gas: Transforming Business

Asset intensive organizations like Oil and Gas have their own industry specific challenges when it com...
Sponsored by

Squeezing the Green: How to Cut Petroleum Downstream Costs and Optimize Processing Efficiencies with Enterprise Project Portfolio Management Solutions

As the downstream petroleum industry grapples with change in every sector and at every level, includin...
Sponsored by

7 Steps to Improve Oil & Gas Asset Decommissioning

Global competition and volatile markets are creating a challenging business climate for project based ...
Sponsored by

The impact of aging infrastructure in process manufacturing industries

Process manufacturing companies in the oil and gas, utilities, chemicals and natural resource industri...
Sponsored by

What is System Level Thermo-Fluid Analysis?

This paper will explain some of the fundamentals of System Level Thermo-Fluid Analysis and demonstrate...
Available Webcasts


The Alternative Fuel Movement: Four Need-to-Know Excise Tax Complexities

When Thu, Jun 4, 2015

Discussion on how to approach, and ultimately embrace, the alternative fuel market by pulling back the veil on excise tax complexities. Taxes may be an aggravating part of daily operations, but their accuracy is crucial in your path towards business success.

register:WEBCAST



On Demand

Prevention, Detection and Mitigation of pipeline leaks in the modern world

Thu, Apr 30, 2015

Preventing, detecting and mitigating leaks or commodity releases from pipelines are a top priority for all pipeline companies. This presentation will look at various aspects related to preventing, detecting and mitigating pipeline commodity releases from a generic and conceptual point of view, while at the same time look at the variety of offerings available from Schneider Electric to meet some of the requirements associated with pipeline integrity management. 

register:WEBCAST


Global LNG: Adjusting to New Realities

Fri, Mar 20, 2015

Oil & Gas Journal’s March 20, 2015, webcast will look at how global LNG trade will be affected over the next 12-24 months by falling crude oil prices and changing patterns and pressures of demand. Will US LNG production play a role in balancing markets? Or will it add to a growing global oversupply of LNG for markets remote from easier natural gas supply? Will new buyers with marginal credit, smaller requirements, or great need for flexibility begin to look attractive to suppliers? How will high-cost, mega-projects in Australia respond to new construction cost trends?

register:WEBCAST


US Midstream at a Crossroads

Fri, Mar 6, 2015

Oil & Gas Journal’s Mar. 6, 2015, webcast will focus on US midstream companies at an inflection point in their development in response to more than 6 years shale oil and gas production growth. Major infrastructure—gas plants, gathering systems, and takeaway pipelines—have been built. Major fractionation hubs have expanded. Given the radically changed pricing environment since mid-2014, where do processors go from here? What is the fate of large projects caught in mid-development? How to producers and processors cooperate to ensure a sustainable and profitable future? This event will serve to set the discussion table for the annual GPA Convention in San Antonio, Apr. 13-16, 2015.

This event is sponsored by Leidos Engineering.

register:WEBCAST


Emerson Micro Motion Videos

Careers at TOTAL

Careers at TOTAL - Videos

More than 600 job openings are now online, watch videos and learn more!

 

Click Here to Watch

Other Oil & Gas Industry Jobs

Search More Job Listings >>
Stay Connected