AEC Pipelines Ltd operates approximately 2500 km of pipeline within Canada and the United States. The AEC Pipelines Ltd. “Pipeline Integrity Group” has responsibility for monitoring and ensuring the continuing safety and reliability of the AEC Pipelines Ltd. pipeline system network within Canada and the U.S.
In carrying out this mandate, the Integrity Group is required to develop and manage large scale pipeline rehabilitation programs involving the assessment and repair of a variety of pipeline defects, including external corrosion and stress corrosion cracking (SCC).
One such rehabilitation program involves the 435-km length Alberta Oil Sands Pipeline (AOSPL) that transports Synthetic Crude product from the Syncrude Plant located at Fort McMurray to Edmonton, Alberta.
This AOSPL pipeline is of spiral weld construction, the pipe joints are externally coated with extruded polyethylene (Shaw YJ1), and the girth welds are externally coated with polyethylene tape wrap. Pipeline outside diameter is 559 mm, nominal wall thickness is 5.16 mm (Gr. 359 and Gr. 414) and heavy wall pipe thickness is 6.35 mm or 7.92 mm (Gr. 359 or Gr. 414).
The pipeline, constructed in 1978, exhibits extensive corrosion and minor SCC at the girth weld locations due to tape wrap coating disbondment and resultant cathodic protection shielding. The four hundred and thirty five (435) km length of pipeline has been excavated and repaired at approximately twenty six hundred (2600) girth weld locations since 1986 including approximately eleven hundred (1100) sites during the last two years.
Major sections of this pipeline may be accessed and excavated only during the winter months. Several crews adhering to an intense work schedule must be utilized in order to complete the necessary number of pipeline repairs within such a short time frame. The employment of a large number of technical specialists for short duration dictates that contract personnel must be utilized within key project supervisory positions.
In 1996, in order to ensure a continuity of critical contract personnel and reduce third party costs, AEC Pipelines Ltd. initiated the formation of a three-year Integrity Alliance involving all of the major contractors working on the AOSPL rehabilitation program. The formation of this Integrity Alliance has resulted in significant program cost reductions and has promoted a “team” approach to rehabilitation projects.
In order to minimize the risk of injury to pipeline rehabilitation project personnel and to provide standards for quality control, the AEC Pipelines Ltd. Integrity Group, in concert with the Integrity Alliance, developed the “The Pipeline Integrity Group Rehabilitation Training and Certification Program”. The program applies to both on-site personnel and visitors and comprises the following individual training and certification approaches:
1. Pipeline Integrity Group Rehabilitation Program Risk Assessment and Safety Guidelines.
2. Pipeline Integrity Group Rehabilitation Training and Certification Program for NDE Personnel.
3. Pipeline Integrity Group Rehabilitation Training and Certification Program for Clock Spring™ Sleeve Applicators.
4. Pipeline Integrity Group Rehabilitation Training and Certification Program for Alberta One Call Response and Field Representation.
These quality control certification and safety training programs are in addition to the many Integrity Alliance specifications that have been developed as a guideline for carrying out critical activities on the pipeline; i.e. pipeline excavation, pipeline re-coating and pipeline grind removal of SCC.