Case Study: Hydrogenated Nitrile (HNBR) Lining for WAC Vessels in Alberta Oil Sands
Customer / Project: Applicator: Spence Corrosion
Control / End User: Nexen
Location: Alberta, Canada
Nexen Energy, a wholly-owned subsidiary of CNOOC Limited, is an upstream oil and gas company. Nexen responsibly develops energy resources in the UK North Sea, offshore West Africa, the United States and Western Canada.
One of Nexen’s core businesses is to develop Canada’s oil sands. When the company began having problems within its weak acid cation (WAC) vessels, it knew it needed a solution.
The protective linings within several water treatment WAC vessels in the Alberta oil sands were failing for a myriad of reasons, including temperatures regularly exceeding 100°C, chemical attacks from the diluent used and high levels of hydrocarbons. There was also abrasion in this application from the oil sands.
After only four months of use, the chlorobutyl linings within Nexen WAC vessels began experiencing catastrophic failures. Harsh conditions, coupled with a poor lining solution, triggered disbonding and swelling of the rubber inside the tank, eventually leading to a complete breakdown.
The chlorobutyl lining was an inadequate product for this application, resulting in significant production delays and damaged tanks. Repair work could take about eight hours assuming necessary materials were on hand, while total lining replacement could take weeks. Nexen needed a more reliable rubber lining that could withstand the environment.
Blair Rubber Co. has a strong working relationship with Spence Corrosion Services Ltd., the applicator of rubber linings for Nexen’s WAC vessels in Alberta, Canada. After examining the chlorobutyl lining on-site, a service representative at Spence Corrosion contacted Blair Rubber Co. to explore alternative lining solutions better suited for the WAC vessels. The application needed a polymer compound that would withstand high temperatures, be chemical and hydrocarbon resistant and have abrasion resistant properties.
Blair Rubber discussed the project with Spence Corrosion, received service conditions data, and studied the very aggressive environment of the vessels. We conducted immersion testing on a potential alternative material with the diluent that is used to get the bitumen out of the ground. As an added measure, Blair Rubber Co. had a third party conduct heat testing to ensure the product could withstand the high temperatures in the vessels.
After all results were in, we knew Enduraflex™ VE627BNI could outperform the competitor’s chlorobutyl product.
Enduraflex™ VE627BNI is a black, soft, hydrogenated nitrile (HNBR) lining for high abrasion and high temperature applications. The HNBR lining can withstand temperatures up to 300 F. The nitrile compound has inherit hydrocarbon resistance properties, with abrasion compounds. Blair Rubber Co. is currently the only company worldwide that offers an HNBR rubber lining.
Blair Rubber Co. offered to provide Spence Corrosion an HNBR lining as a trial for the WAC vessels. After the test run, Nexen chose to line the rest of its vessels with the VE627BNI lining. In total, four vessels were lined.
“It was a pleasure working with Blair on this project as materials were delivered on time and on budget,” said Norman Spence, president, Spence Corrosion.
“Our rubber lining applicators in the field liked working with the new VE621BNI rubber materials and we look forward to working with Blair in the future.”
The HNBR linings were applied in 2014 and continue to endure the harsh conditions of the Alberta oil sands. The superior product allowed Nexen to avoid costly production delays caused by rubber lining failure.
“The WAC vessels in the Alberta oil sands are an extremely aggressive environment,” said Tom Bogart, Blair Rubber Co. export sales manager.
“The chlorobutyl linings were just not cutting it. They were failing after only a few months, which created undesired downtime for Nexen. Our VE627BNI HNBR lining is superior to anything in the market for harsh conditions with high temperatures and hydrocarbons. We offered to line a tank as a trial back in 2014 and it’s held up against everything. The polymers used in the HNBR compound allow it to withstand high temperature situations, and is resistant to chemicals and hydrocarbons.”
Blair Rubber Co. understands the needs of users. Our vertically integrated manufacturing process ensures that we provide the shortest product lead times in the industry. For this application, we were able to manufacture the rubber lining and get it on the job site within three weeks.
The WAC vessels project has created a long-lasting relationship between Blair Rubber Co., Spence Corrosion and Nexen. The VE627BNI continues to be a viable product for this application.