Representation of fluid sampling at the reservoir

InSitu GOR

Reservoir fluid GOR and CGR sensor

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Greater accuracy in downhole, real-time optical determination

The enhanced composition measurements of the InSitu GOR sensor of the InSitu Fluid Analyzer system are used to determine the gas/oil ratio (GOR) and gas/condensate ratio (GCR) from the vaporizations of the hydrocarbon and CO₂ components at standard conditions for flashing a live fluid.

This method improves both the range and accuracy over those of previous-generation optical tools.

The wavelength ranges of the filter array and grating optical spectrometers are optimized for the detection and analysis of hydrocarbon and CO₂ components in crude oil and natural gas, as well as for the determination of water content and pH. The measurement of optical density (OD) is simply the base-10 logarithm of the ratio of incident light to the transmitted light through a cross-section of reservoir fluid in the flowline. OD is presented as a dimensionless unit, whereby one OD absorbance unit implies a 10-fold reduction in light intensity. For example, OD = 0 means 100% of light is transmitted, OD = 1 indicates 10% light is transmitted, and OD = 2 means 1% light is transmitted. The measurements are conducted across the entire frequency spectrum of light in the Vis-NIR range.

Why you need a GOR measurement

GOR is a fluid purity indicator because it represents the level of contamination in a reservoir fluid being extracted for DFA or sample collection. Both DFA and laboratory analysis are critically dependent on obtaining fluid that is as pure and uncontaminated as possible. However, fluid extraction must strike a balance between purity and pumping time.

When the GOR measurement levels off, contamination is no longer compromising sample quality, and analytical results can be entered into reservoir simulation models with confidence.