Analyzing Greenhouse Gas Emission Leading Indicators: Case Study of Compressor Profile Optimization
Suradech Kongkiatpaiboon, Asit Apornsupavit, Songkiet Manoharn, Chawanin Phetket, Sasiwan Nimanong, Saranya Prabhasawasdi, Worasak Charungrattanapong
SPE Asia Pacific Oil & Gas Conference and Exhibition (APOGCE), Perth, Australia, 2024 · SPE-221211-MS
Most emissions dashboards report fuel burned and gas emitted, which only tells you about a problem after it has happened. The team benchmarked fuel use across similar equipment and found that the gas compressors were running against a design pressure profile that was far higher than the sales pipeline now needs. They picked out three valve positions as early-warning indicators of wasted compression energy. They then re-tuned the compressors and their control set points, and built a dashboard with alerts so that operators act on these indicators before the fuel is spent.
Key results
- Gas compressors accounted for more than 50% of facility energy use
- More than sixty instrument set points were re-adjusted to widen the compressors' allowable operating range
- On one platform, compressor discharge pressure was brought close to sales-pipeline pressure so the back-pressure valve no longer throttled flow; on another, the recycle valves were closed down by cutting compressor speed. Both changes gave significant fuel-gas and GHG savings (the paper does not give tonnage or percentages)
Approach
- Ranked equipment by energy use through workshops and subject-matter-expert interviews, which identified gas compressors as the dominant fuel consumers
- Benchmarked fuel use and recycle-valve opening across similar compressor packages using box plots, alongside Sankey-style fuel-flow analysis
- Defined three leading indicators: anti-surge valve opening, train recycle valve opening and discharge back-pressure control valve opening
- Checked equipment adequacy and adjusted shutdown and alarm set points so compressors could run at lower speed and closer to pipeline pressure
- Deployed a leading-indicator dashboard that estimates potential CO2 savings, with automated e-mail alerts when an optimization opportunity goes unaddressed
The problem
Gas compressors, the largest fuel users on the facilities, were wasting energy through recycling and throttling because sales-pipeline pressure had fallen well below original design while compression ratios stayed unchanged.
Tools & methods
Summary written for this site from the published paper. For figures, data and the full method, read the paper on OnePetro.