Natural gas strain, or gas strain, refers to the variations in gas composition from different sources or geographical locations. It involves not only the presence of the primary components such as methane and ethane but also impurities and traces of other higher hydrocarbons or gases like nitrogen, carbon dioxide, and hydrogen sulfide. Understanding the variations in gas strain is crucial for optimizing gas processing, minimizing environmental impact, and ensuring safety in gas handling, transportation, and end-use applications.