Current underground flow lines have safety and integrity threats that impact people and production. The flow-lines are operating in a highly corrosive environment, where corrosion inhibitor is required internally and current cathodic protection and coating are ineffective to protect the pipeline externally:
- High pressure (1350 to 1400 psig), high temperature (275 – 300°F, intermittent peak of 325°F), high velocity gas and CO2 content of around 7%-mole
- Shallow out-cropped coal seams across the field, combined with water, creates an acidic environment (pH 2 – 4)
- Underground Carbon steel with coolers
- Aboveground Carbon Steel
- Aboveground Duplex
Tools and Techniques:
- Alternatives reviewed
- Preliminary Concept Selection Study
- Qualitative Risk review
- Discussion by internal integrated team
To deliver an optimum design concept and execution strategy for the entire Pipeline System (New & Existing Wells) to mitigate current risk of system integrity because of highly corrosive environment.
Following is the result of Multi-Attributes Evaluation between alternatives:
Conclusion (Preferred Alternative):
Installing coolers is preferred solution especially on existing lines. Aboveground flowline may be applied for optimization for future flowlines and pipe replacement.
- Limits time operating with high risk of asset integrity, process safety and occupational safety
- Opportunities to optimize certain wells
- Scope of work for 3rd party FEL-1 engineering is coolers as the preferred solution.
Performance Monitoring and Post-Evaluation:
All options area are within existing plant boundary area and no land acquisition is required. It means that if there is significant discrepancy cost within the options, the evaluation must be redone.
- Sullivan, William G., Wicks, Elin M. & Koelling, C. Patrick. (2012). Engineering Economy 15th Edition, Chapter 14 – Decision Making Considering Multiattributes. Singapore: Prentice Hall, Inc.
- AACE International Recommended Practice (2003). Recommended Practice No. 16R-90 Conducting Technical and Economic Evaluations – as Applied for the Process and Utility Industries. AACE International
- Liu, Henry (2003). Pipeline Engineering. Boca Raton, Fla: Lewis Publisher
Michael Bassard & Diane Riter (2010). The Memory Jogger 2nd Edition. Canada: GOAL/QPC