END USER FEATURE / EMISSIONS
Table 1. Comparison of conventional vs. optimised GCP shutdown fuel gas management. Component Conventional practice Optimised practice Main fuel gas valve
Throttled to minimum flow( 300 MSCF per Year)
• Calibration and verification of flow monitoring instrumentation to confirm zero flow through the main fuel gas line during shutdown.
• Update of the Operating Procedures( OPs) and Management of Change( MOC) documentation.
The modifications were reviewed against the facility’ s Process Hazard Analysis( PHA) and Layer of Protection Analysis( LOPA) to confirm that no new process safety risks were introduced. The pilot valve retention was specifically validated as the mechanism maintaining turbine safety function integrity in the absence of main fuel flow( Figure 1).
Safety assurance framework
The initiative maintained full compliance with the facility’ s Safety Integrity Level( SIL) requirements. Furthermore, during the Hazop and SIL studies revalidation, the initiative related loop has been reviewed by the team and validated. Key safety considerations addressed included:
• Flame detection and turbine trip logic: verified to remain active and unaffected.
• Emergency Shutdown Device( ESD) functionality: confirmed independent of main fuel gas valve position.
• Flare Pilot valve: remained operating with lower flaring rate to maintain plant safety.
• Restart protocol validation: Hot-startup and cold-start-up sequences tested against manufacturer specifications and confirmed within acceptable parameters and have been validated by Dispatcher.
Fuel gas savings
Based on metered data collected over a 12-month post-implementation monitoring period, the initiative delivered the following primary outcomes.
Restart performance
A key operational concern prior to implementation was the potential impact on turbine restart reliability. Post-implementation monitoring confirmed that warm-start
Fully closed- zero fuel flow
Pilot valve |
Open( active combustion) |
Retained open( ready for restart, no |
|
|
active combustion) |
Combustion during standby
Continuous at minimum rate
Eliminated
Restart readiness |
Immediate( hot turbine) |
Standard warm / cold start |
|
|
( acceptable per operating envelope) |
and cold-start sequences remained within manufacturer-specified time envelopes. No increase in startup failures, turbine trips, or flame detection events was recorded over the 12-month monitoring period. This finding validates the technical premise that pilot valve retention alone is sufficient to maintain restart readiness without sustaining active combustion.
Scalability assessment
Initially, the Initiative was implemented at GCP-3 in 2024, and was then assessed for applicability across other GCP units within the facility and comparable facilities within the Eastern Province operations. The extrapolation across two similar GCP units suggests an increase in annual fuel savings in the range of 200 – 300 MMSCF and CO2 avoidance of 15,000 tons per annum. These projections are pending validation through phased rollout currently under planning, which is mainly dependent of shutdown period.
GHG emission reduction
The elimination of standby combustion directly reduces Scope 1 GHG emissions under the GHG Protocol Corporate Standard. Using an emission factor of approximately 50.61 tones CO2 per 1 MMSCF of natural gas combusted( molecular weight basis for methane-dominant gas), the estimated annual CO2 savings per unit are 15000 tones, depending on shutdown frequency and gas composition. This contributes directly to corporate GHG intensity reduction targets under DEEP. This initiative directly supports the following United Nations Sustainable Development Goals and Saudi Arabia’ s national climate commitments under its Nationally Determined Contribution( NDC) submitted to the UNFCCC.
Air quality co-benefits
In addition to CO2, the elimination of standby combustion reduces the emission of nitrogen oxides( NO x), unburned hydrocarbons( UHC), and carbon monoxide( CO) associated with low-load turbine combustion- conditions known to produce disproportionately high specific emissions relative to design-point operation. Improved local air quality in the vicinity of pipeline facilities represents a tangible co-benefit for surrounding communities and ecosystems.
Economic value
The economic value of recovered fuel gas is a function of the internal transfer price or opportunity cost assigned to fuel gas within the operating company’ s accounting framework. At Saudi Aramco, fuel gas displaced from non-productive standby combustion represents gas that may alternatively be routed to the Master Gas System( MGS) for monetisation or processing. Even at conservative internal values, the annual economic benefit per GCP unit is estimated in the range of USD 500,000, depending on gas price and shutdown frequency.
Conclusions
Based on this technically grounded and operationally validated approach to eliminating non-productive fuel gas combustion during GCP shutdown events, we can conclude:
Table 2. Key Performance Indicators- pre- and post-implementation Parameter Baseline( pre-implementation) Post-implementation
Total shutdown duration( annual)
~ 4500-5500 hours / year 4500-5500 hours / year
Standby fuel gas flow rate ~ 300 MSCF per year. 0 MSCFD Annual fuel gas saved— ~ 299.6 MMSCF / year. CO2 emissions avoided— ~ 15162.7 tons CO2 / year
Estimated annual cost saving
—
USD 500,000 / year depending on Gas price in market
46 Valve World October 2026 www. valve-world. net