1. Northern Pipelining & Practical Experience
Presentation to:
APEGGA
April 21, 2005
Calgary
APEGGA Northern Pipelining

2. Topics Enbridge (NW) Pipeline System Overview
“Northern” Pipeline Challenges and Successes
Maintenance and Monitoring
Inspection and Integrity Management
Reporting
The people that make it possible
APEGGA Northern Pipelining

3. Quick Facts Enbridge (NW) Pipeline System Constructed: 1983 – 1985
Diameter: mm
Length: 869 km
Design: Limit States
Features:
140 defined water crossings
2 major rivers
150 significant slopes
ambient temperature pipeline
Design Pressure: 9930 kPa
Inuvik
Norman Wells
Zama
Ft. Simpson
Wrigley
APEGGA Northern Pipelining

4. Quick Facts Enbridge (NW) Pipeline System
Throughput: 30,000 BPD (4,800 m3/d)
One shipper from Norman Wells to KP Two shippers from there to KP 869 (Zama)
Three (3) Pump Stations:
1 natural gas powered (NW)
2 diesel powered (WG & MC)
Crude Characteristics:
Density = 827 kg/m3
Pour Point = -50° Celsius
RVP < = 103 kPag
Viscosity = 2.0 cSt.
Remote Operations from Edmonton
Aerial View of Norman Wells
APEGGA Northern Pipelining

5. “Northern” Pipeline Challenges
Unique “Northern” P/L Issues
Capital Cost
Geography and Remote Access
Permafrost
Enbridge Experience Applied to
Future Development
Proven sub-surface construction in permafrost
Proven methods of monitoring pipeline integrity
Inuvik
Norman Wells
Zama
Ft. Simpson
Wrigley
APEGGA Northern Pipelining

6. Norman Wells Successes: Design Innovation
Operating temperatures
Limit States Design
lower cost
strain limit 0.5%
Integrity monitoring
One of the key design considerations was the operating temperature for the Norman Wells pipeline. The crude oil is chilled leaving the Imperial Oil Resources processing facilities at Norman Wells before entering the pipeline and it soon establishes equilibrium temperatures with the surrounding soils. The pipeline then has minimal impact on the ground temperature and does not materially affect thaw or freeze cycles.
After the first few years of operation and monitoring the pipeline, Enbridge experimented with higher operating temperatures leaving Norman Wells. It was determined that, at times of the year, warmer oil could be transported without affecting pipeline performance in the permafrost areas. This finding will be of great benefit for the design of the next pipeline system.
Probably the most innovative approach taken with this pipeline design was the concept of Limit States design. Limit States design is, simply put, designing the pipeline to meet the conditions expected rather than designing to some arbitrary code requirement. Knowing that the pipeline would be subject to movement in areas of discontinuous permafrost, this design approach allowed the pipeline to actually deform slightly under certain external loads and still stay within safe operating limits. The strain limit was conservatively set at 0.5%. Norman Wells pipeline was the first on-shore pipeline in North America to take this design approach.
Key to this approach is the need to monitor pipe movement throughout the pipeline’s operating life. A tool was developed specifically for this pipeline to accomplish this and I will describe this approach later
APEGGA Northern Pipelining

7. Norman Wells Successes: Permafrost Challenges Met
Design
Environmental/ Geotechnical
Right of Way
trenching
Ice Rich
APEGGA Northern Pipelining

8. Norman Wells Successes: Slopes – Then and Now
1984
1997
Design
Environmental/ Geotechnical
Right of Way
trenching
slope stabilization
The slopes have performed exceptionally well during the 16 years of operation.
This slide shows the right of way with wood chip insulation 13 years after installation. There is no appreciable degradation of the wood chip cover.
Wood chip insulation may also be the appropriate solution for slope stabilization for the upcoming pipelines from either the Mackenzie Delta or Alaska Highway routes along the more southerly areas. However, in more northerly areas, availability of wood chips could become an issue. Other methods of insulation may prove more effective.
APEGGA Northern Pipelining

9. Experience: Permafrost
Region requiring design consideration for permafrost
Conventional pipeline design and construction
Area of sporadic permafrost that requires minimal pipeline design and construction considerations for permafrost
Map and Diagram from Geological Survey of Canada website
APEGGA Northern Pipelining

10. Norman Wells Successes: Dealing with Ice
Design
Environmental/ Geotechnical
Right of Way
trenching
slope stabilization
thaw settlement / frost heave
Ice lens
As I indicated earlier, a certain amount of pipe movement due to settlement or frost heave is to be expected in the design of any northern pipeline.
This slide shows an example of an ice lens exposed during the trenching of the Norman Wells pipeline. Ice lens can either be thawed or created by the operation of a pipeline in northern environments and create the potential for pipe movement.
To ensure design limits are not exceeded, it is imperative to monitor pipe movement.
APEGGA Northern Pipelining

11. Inertial Inspection Runs – GEOPIG
APEGGA Northern Pipelining

12. Integrity Management in Permafrost
Geo-Pig
In 1997 and 1998 large deflections were occurring as shown in the 3D graph produced from the Geopig data.
A scheduled repair of the pipeline was performed in February, 1999 with the exposed pipeline wrinkle exactly matching the results of the GeoPig
The use of an in-line inspection tool such as this one will be critical to the design and operation of any gas pipelines in the north.
APEGGA Northern Pipelining

13. Maintenance Activity – Pipe Replacement
APEGGA Northern Pipelining

14. Maintenance Activities
APEGGA Northern Pipelining

15. Maintenance Activities to Present
APEGGA Northern Pipelining

16. Monitoring Activities
APEGGA Northern Pipelining

17. Reporting to Regulators
Annual Reports
Operations & Maintenance Activities
Condition of Pipeline
Terrain Monitoring
Slope Monitoring and Performance
Operations & Monitoring Program
Right-of-way Assessment
In 1985, Enbridge completed construction of an 870-km pipeline from Norman Wells, Northwest Territories to Zama, Alberta. It is the first pipeline to be constructed through permafrost in Canada's north.
Because of the sensitive nature of the area, Enbridge undertook monitoring to determine the effects of the pipeline construction and operation on the environment, the condition of the right-of-way including river crossings and slopes and the condition of the pipeline. The monitoring program and schedule were approved by the National Energy Board in October, 1984.
The results of the 1985 monitoring programs indicated that the pipeline did not realize any excessive stresses and that no significant environmental impacts resulted from pipeline construction or operations. While pipeline development did generate several minor terrain problems, overall terrain performance was satisfactory. Post-construction restoration and maintenance programs were overwhelmingly effective and mitigated any such problems.
Nevertheless, continuing conscientious monitoring was deemed necessary to identify terrain changes and allow for early restorative works. Annual reports such as this, describe the results of the monitoring activities and restoration and maintenance programs Enbridge has undertaken over the past 20 years.
APEGGA Northern Pipelining

18. Pipeline Maintenance Hauling propane to remote area valve sites.
These are tracked carriers that utilizes vulcanized rubber tracks for minimal environmental disturbance. They are recommended for use over snow and ice and are most commonly used in oilfield and geophysical operations in environmentally sensitive areas like northern terrain.
Enbridge uses several different models: Nodwell, Chieftian, Hidebrand
APEGGA Northern Pipelining

19. Field Personnel
Employees are permanent residents of the communities of Norman Wells and Ft. Simpson.
They provide significant contributions to the quality of life in the communities through their volunteer activities.
Successful and enduring positive northern relationships are built and maintained on the basis of mutual honesty, respect and trust.
APEGGA Northern Pipelining

20. Questions
APEGGA Northern Pipelining