Hydrocarbon and Non Hydrocarbon Compositions of the Associated Natural Gas at Different Pressures Using Gas Chromatography

The hydrocarbons and non hydrocarbon of associated natural gases from the studied western desert reservoir at ambient temperature at different pressures were studied by gas chromatography. The mol percent of iso-paraffins are generally less than that of the corresponding normal paraffin. At the pressure range up to 1500 psig the mol percent of CH4 decreases slightly with reducing gas pressure, however, the heavier hydrocarbons, up to C6+ show an opposite variation. When the pressure is reduced to 2500 psig, the percent of the heavy ends of the liberated gases sharply decrease with decrease in gas pressure. The CO2 content of the gases is much less sensitive to pressure variation. N2 and CO2 were detected as inorganic components; however, H2S was not detected in the studied samples.