See the unseen and protect the pipeline: those objectives underpin contemporary gas-quality assurance. Industry practice has long relied on a single parameter—hydrocarbon dewpoint—to certify a stream as dry. However, when Hydrocarbon Dewpoint (HCDP) is determined by gas Chromatography. The heavier hydrocarbons are combined and measured as one figure (C6+). While this is adequate for Btu calculations, the exact makeup of these heavier hydrocarbons can significantly change the HCDP. For example, when the HCDP of a typical gas sample is calculated using one of six commonly accepted equations of state, the calculated dewpoints range from –92.9 °F (–69.4 °C) to +93.5 °F (+34.2 °C), this spans 186.4 °F (103.6 °C) making the result little more than conjecture.
The financial and operational consequences of that uncertainty are significant. A liquid-volume fraction of 0.1% in a gas flow of 100 MMSCF/day can discharge more than 10,000 US gal (approximately 37 900 L) of natural-gas liquids each day, impairing throughput and contaminating turbines, compressors and catalyst beds while gas chromatography and conventional analysers continue to indicate dry gas.
To add to the uncertainty, the conditions in a gas pipeline are far from the equilibrium required for good measurements to be obtained. Observations in the field show that when gas is flowing over stratified liquid flow at the bottom of the pipe, low HCDP are reported (indicating a dry gas) that change when the gas flow slows and significantly increase when the gas flow stops and the volatile liquids vaporise into the stationery gas.
Recognising these limitations, Process Vision created, LineVu. This ATEX and IECEx certified camera is installed on standard tapping points and transmits high-definition video of the flowing gas. Image-processing algorithms identify mist or stratified liquid in real time and generate immediate alarms, transforming an otherwise invisible threat into actionable information. Field recordings obtained at custody-transfer locations on three continents have revealed persistent mist, ribbons of natural-gas liquids and compressor oil migrating through pipework, none of which were detected by chromatographic measurements carried out in parallel.
The meta data from images and process data can then be correlated in PhaseVu AI, a machine leaning model that can be used as a diagnostic tool to determine the route cause of the liquid carryover problem.
Natural-gas operators obtain direct confirmation of gas stream quality while production continues uninterrupted. Regional managers can present unequivocal visual evidence during performance reviews, thereby expediting approval for remedial investment. Metering managers, whose reputations depend on the integrity of custody-transfer data, benefit from a continuous, independent verification of pipeline. Local operating teams respond more quickly to separator or heater adjustments because they act on clear images. Asset-integrity engineers obtain early warning of conditions that could compromise compressors or gas turbines, while observing lower risk exposure, accelerated pay-back and enhanced confidence.
Leading networks therefore retain dewpoint modelling for design and planning purposes but complement it with continuous visual confirmation at critical nodes such as import and export at gas processing units, compressor inlets, gas turbine inlets and LNG feed lines. When the camera exhibits the characteristic shimmering heat-haze of a dry stream, standard control logic is maintained; when any indication of aerosol or film appears, targeted sampling, separator inspection or a controlled reduction in flow rate can be initiated to prevent escalation.
Every frame transmitted by LineVu carries a precise time stamp, allowing seamless integration with SCADA and DCS platforms. Machine-learning applications convert the video data into quantitative key-performance indicators, including liquid-volume fraction, liquid flow and frequency of contamination events.
The ongoing transition to blended hydrogen, biomethane and CO2 capture increases the variability of phase behaviour and complicate traditional dewpoint calculations. A camera, being composition-agnostic, registers liquid presence irrespective of molecular mixture, thus providing future-proof assurance. In an operating environment that demands higher availability, lower emissions and rigorous commercial transparency, continuous visual monitoring offers a single, objective point of reference that supports decision-makers across technical and financial functions.
Gas quality, once inferred indirectly, can now be verified in real time. Reliable evidence, demonstrable results and trustworthy data become attainable outcomes when a pipeline can be observed rather than assumed.
