Moving Heavy Oil

Demanding requirements of transporting dry bitumen in the 12-in. OD MacKay River Pipeline in Alberta led to development of an innovative coating system.

Material selection considered pipeline-operating requirements, operating temperatures of up to 130° C (266° R), environmental conditions, coating application processes in shop and field, reparability, and material costs.

An assessment of existing material testing procedures was performed and a number of standard qualification tests were modified to qualify coating materials. This qualification led to selection of a robust, cost-effective coating system.

While historical performance information is not yet available, long-term monitoring will likely validate the design and application of the insulated three-layer coating system used on the MacKay River Pipeline.

Continued development of the oilsands in the Fort McMurray area of Alberta led to a need for the pipeline, which moves bitumen production from the MacKay River area with little or no dilution (dry bitumen).

To flow without diluent, the bitumen must be heated, and heat must be retained by use of a continuous layer of insulation to ensure viscosity remains low. The high operating temperature and the environment through which the pipeline passes were major challenges for design and construction.

This article focuses on design, selection criteria, and testing of the coating system and discusses the important aspects of construction.

The 35 km (22-mile) MacKay River Pipeline moves dry bitumen from Petro-Canada’s MacKay River production facility to Enbridge Pipelines Inc.’s Athabasca terminal. There, the bitumen is blended and transported via the Athabasca pipeline to Hardisty, Alta.

Design capacity of the MacKay River Pipeline is 7, 000 cu m/day (44, 000 b/d).

Environmental and operating conditions of the pipeline posed substantial challenges for selection of a coating system.

An operating temperature of 120° C, with the possibility of short excursions up to 130° C. and a design life of 30 years substantially limited the range of feasible coating materials.

From an operational standpoint, it was necessary to design the coating system so that sufficient heat would be retained to enable the pipeline to be shutdown for 2 days and subsequently restarted while carrying an unblended product.

The right-of-way, consisting of segments of day and wet (muskeg) terrain, imposed further design constraints upon the coating system.

Coating material testing began in October 2000. Pipe coating began in July 2001. Construction began in September 2001 and was completed by mid October 2001.

Pipeline operation began in December 2002.