Methane Conference 2019

Industrial Methane Measurement Conference 2019 - Abstract

Abstract Title: The Lacq controlled release experiment: detection and quantification of controlled gas leaks using CRDS (cavity ring down spectroscopy) measurement with a local-scale dispersion model
Presenter Name: Dr Susan Gichuki
Co-authors:Dr Pramod Kumar
Dr Ford Cropley
Dr Gregoire Broquet
Dr Camille Yver
Dr Olivier Laurent
Company/Organisation: Laboratoire des Sciences du Climat et de l'Environnement(LSCE)/Universite de Versailles St. Quentin en Yvelines(UVSQ)
Country: France

Abstract Information :

With the signing of the Paris Climate agreement there are now increased efforts to mitigate greenhouse gas emissions from the oil and gas industry for safety reasons and to comply with requirements in an increasingly regulated environment. One of the major challenges in mitigating emissions in oil and gas facilities is being able to detect and quantify fugitive leaks in a timely manner in order to repair them, and as part of the long-term monitoring of sites. A controlled release experiment was carried out by TOTAL to evaluate the ability to detect and quantify such leaks. We deployed CRDS (cavity ring down spectroscopy) analyzers in a hybrid SUV and from fixed points to make measurements of simulated leaks of different magnitudes at TOTAL’s facility in Lacq, France. Over the course of 4 days, controlled releases were emitted ranging from 0.1 to 300 g/s for methane (CH4) and 0.2 g/s to 150 g/s for carbon dioxide (CO2). To complement the fixed sampling points, transects were made around the site for mobile measurements. In order to estimate the emission rate, a local-scale Gaussian dispersion model is adopted with necessary input meteorological and turbulence parameters from the available observations. The dispersion model was trained using releases for which the emission rate was known. We used an atmospheric transport inverse modeling approach relying on CH4 concentration, fixed measurement points, and mobile transects across the plumes, and local scale dispersion modeling.