Natural gas that comes from oil wells is typically termed “Associated Gas (AG)” or “Hot natural Gas (HNG)”. HNG contains methane, ethane, propane and other heavier hydrocarbons such as butanes, pentanes, hexanes and etc. In addition, raw natural gas contains water vapour, hydrogen sulphide (H2S), carbon dioxide (CO2), nitrogen (N2) and other compounds. Typically HNG is very high in heating value and low in methane number. After removing the acid gas and excess moisture, this gas is often used for power generation. If the methane number is too low and heating value is high, this gas is not suitable for most gaseous fuel reciprocating engines (or gas engines). Excessive amounts of the heavier hydrocarbons leads to potential issues like detonation, carbon deposits, and gumming eventually causing permanent damage and loss of productivity. Furthermore, engines are required to operate at lower power settings when running on associated gas lead ing to incr ease oil consumption, higher exhaust temperatures, increased wear and tear resulting in higher maintenance cost. When engines are running derated, this leads to increased exhaust temps, increased oil consumption, excessive wear, and higher maintenance cost, not the other way around.