Emissions from gas processing platforms to the atmosphere-case studies versus benchmarks

This study compares oil and gas industry benchmark non-methane volatile organic compounds emission data with predicted and reported emissions from a number of recent case studies. Specifically, we contrast predicted emissions from the Tamar and Leviathan processing platforms in the Eastern Mediterranean with actual emissions where available, and with a compilation of industry benchmarks. This work reveals a series of flaws in the adopted EIA practices in the case studies discussed, starting from the emissions model that grossly underestimates intermittent NMVOC and benzene emissions relative to available data from other sites, and the unrealistic assumption of a constant and uniform emission profile in contrast to real world emission scenarios that are characterized by discrete large emission events. Furthermore, the dispersion model used in the EIAs as part of the request for a business (emissions) permit has a number of significant failings, including the use of an unsuitable model, use of over-simplistic meteorological inputs, and lack of consideration of critical dispersion phenomena. This study highlights the need to rethink the currently used environmental impact assessment and atmospheric permit request methodologies in the oil and gas industry, which rely on unrealistic uniform emission models.