Study of Natural Gas Quality Specifications and Testing Methods at Receiving Terminals in Lagos

Natural gas quality control at receiving terminals is essential for protecting downstream equipment, ensuring consumer safety, and maintaining contractual gas specifications. This study examines the gas quality specifications applied at natural gas receiving terminals in Lagos, including the Egbin Power Plant gas receiving facility and commercial industrial reception terminals in Ikorodu and Apapa. The research employs a technical review methodology combining laboratory analysis of gas samples, review of quality test certificates from NLNG Bonny and Escravos Gas Processing Plant, and interviews with terminal quality assurance engineers. Quality parameters assessed include higher heating value (HHV), Wobbe Index, hydrogen sulphide content, carbon dioxide content, water dewpoint, and hydrocarbon dewpoint, compared against the Gas Transportation Agreement (GTA) specifications and international standards including ISO 13686. The study investigates the frequency and nature of quality specification non-conformances, their causes, and the contractual and operational consequences. Findings reveal that water dewpoint exceedances and elevated hydrogen sulphide episodes are the most frequently occurring non-conformances, attributable to inadequate dehydration unit performance at upstream processing plants. The study recommends enhanced upstream quality monitoring, automated quality alarm systems at terminal entry points, and revised contractual off-specification gas handling procedures. These findings support the strengthening of gas quality governance across Nigeria's gas supply chain. Keywords: gas quality, receiving terminal, Lagos, Wobbe Index, gas specifications.