ISO/TR 14749:2016

Overview - ISO/TR 14749:2016 (Online gas chromatograph for upstream area)

ISO/TR 14749:2016 provides guidance for using an online gas chromatograph (GC) to determine hydrocarbon components up to C7+ in natural gas within the upstream petroleum industry. The Technical Report explains the GC principle, sampling and sample-conditioning requirements, selection and evaluation of analysers, calibration and verification procedures, maintenance, alarm/diagnostic practices, and data handling for custody transfer and process monitoring.

Key topics and technical requirements

• Principle of measurement: continuous, automated separation and detection of volatile hydrocarbons using carrier gas, columns and detectors with integrated data processing.
• Gas composition scope: major (methane to C7+), minor and trace components; emphasis on representative sampling for accurate energy/calorific calculations.
• Sampling and conditioning:
  • Properly designed sample probe, pressure regulation and short, insulated sample lines to avoid condensation and liquid carryover.
  • Recommendations on probe location (preferably 20 pipe diameters downstream of disturbances, minimum accepted 5 diameters in constrained upstream situations) and tip placement (top of horizontal pipe).
  • Heat tracing when ambient temperature is below hydrocarbon dew point - maintain sample line ~10 °C above dew point; unit energy thresholds (≈38.73 MJ/SCM or 1 040 btu/scf) often indicate need for heat tracing.
  • Materials: stainless steel common; duplex stainless considered for high H2S (>50 ppm).
• Pressure management: account for high upstream pressures (example figures cited: >4 137 kPa / 600 psi) and low GC inlet pressures (