The goal of reducing anthropogenic methane emissions, in particular those arising from oil and gas operations, will require the implementation of routine and effective monitoring, both to detect repairable emissions and to reliably report emitted quantities. This will mean a transition from research investigations to more formal requirements for monitoring which will be the responsibility of industry. Methane emissions are particularly challenging to measure as the sources are highly inhomogeneous in terms of the ranges of their emission characteristics such as emission rate, temporal behaviour, and the wide variety of potential sources of emissions (ducted emissions, vents, fugitive leaks from components, storage tanks, flares, onshore and offshore facilities). To enable baselining and reliable reporting from across different parts of the oil and gas industry, and to address the different needs from detection to quantification, a range of different methods based on different measurement technologies are needed. This has resulted in a large number of available and developing approaches. Industry will need confidence in the emissions data they report as they will be used to guide emission reduction activities and to report into international frameworks such as the IMEO. In future there will be increasing regulatory pressure. To support these growing requirements, and to support the selection of appropriate methods, there is therefore a need for a metrology framework to ensure the quality, reliability, comparability and suitability of measurement methods. It is important that the measurement uncertainties associated with methods are well understood including key sources of uncertainties, and the impact of the use of methods in different conditions and locations. This will not only support the selection of appropriate methods, but also enable the interpretation and comparison of data between sources and over different scales (both temporal and spatial).This talk will outline these issues, review the requirements for defining clear measurement objectives and performance requirements and provide an illustration of what such a metrology quality framework would look like. The talk will discuss the issues around determining the uncertainties in methane emission measurements and in particular in derived data such as emission rates, and the use of validation studies and controlled releases will be discussed. It will also provide an overview of current activities to develop standardised methods for monitoring methane emissions and to develop the tools to support the evaluation of such methods.

The quickly developing drone technology can be used efficiently in the field of pipeline leak detection. The aim of this article is to provide drone mission concepts for detecting releases from pipelines. It provides an overview of the current applications of natural gas pipeline surveys, it considers environmental conditions by plume modelling, it discusses suitable commercially available sensors, and develops concepts for routine monitoring of pipelines and short term missions for localising and identifying a known leakage. Suitable platforms depend on the particular mission and requirements concerning sensors and legislation. As an illustration, a feasibility study during a release experiment is introduced. The main challenge of this study was the variability of wind direction on a time scale of minutes, which produces considerable differences to the plume simulations. Nevertheless, the leakage rates derived from the observations are in the same order of magnitude as the emission rates. Finally the results from the modeling, the release experiment and possible drone scenarios are combined and requirements for future application derived.

Industries, governments, and regulators need trustworthy emissions data to enable them to make informed decisions regarding methane abatement strategy and policies. There are many differing data reporting metrics, as well as a diverse range of both emission sources and methods for monitoring emissions. Different data structures and terminologies can be used to describe similar objects, activities, or characteristics associated with methane monitoring. There is no currently accepted definition of what constitutes a methane monitoring method. Since there is no common basis to describe this information, confusion concerning language, definitions, and terminology can arise which can undermine confidence in data. This paper describes a framework, based on a set of taxonomies and a common lexicon, which aims to address these issues by providing a common structure in which data requirements, emission sources and monitoring methods can be described. The principles of metrology and quality assurance are embedded into this framework along with a means to define the temporal and spatial scales of the reporting and monitoring. It is envisaged that this framework will be developed into a standard to help facilitate more reliable transfer of information between stakeholders internationally. Usage examples for this framework include: to aid the development of test standards (between test laboratories, site operators, and standards bodies); to help ensure the most cost-effective monitoring methods are deployed for a specific purpose; to help identify technological and methodological gaps between what monitoring is needed and what is available, or to help drive more focused innovation in this field.

Atmospheric ethane can be used as a tracer to distinguish methane sources, both at the local and global scale. Currently, ethane can be measured in the field using flasks or in situ analyzers. In our study, we characterized the CRDS Picarro G2201-i instrument, originally designed to measure isotopic CH4 and CO2, for measurements of ethane-to-methane ratio in mobile-measurement scenarios, near sources and under field conditions. We evaluated the limitations and potential of using the CRDS G2201-i to measure the ethane-to-methane ratio, thus extending the instrument application to simultaneously measure two methane source proxies in the field: carbon isotopic ratio and the ethane-to-methane ratio. First, laboratory tests were run to characterize the instrument in stationary conditions. Subsequently, the instrument performance was tested in field conditions as part of a controlled release experiment. Finally, the instrument was tested during mobile measurements focused on gas compressor stations. The results from the field were afterwards compared with the results obtained from instruments specifically designed for ethane measurements. Our study shows the potential of using the CRDS G2201-i instrument in a mobile configuration to determine the ethane-to-methane ratio in methane plumes under measurement conditions with an ethane uncertainty of 50 ppb. Assuming typical ethane-to-methane ratios ranging between 0 and 0.1 ppb ppb−1, we conclude that the instrument can accurately estimate the “true” ethane-to-methane ratio within 1σ uncertainty when CH4 enhancements are at least 1 ppm, as can be found in the vicinity of strongly emitting sites such as natural gas compressor stations and roadside gas pipeline leaks.

(10/12/2018) Validation of landfill methane measurements from an unmanned aerial system: Project SC 160006 Landfill gas is made up of roughly equal amounts of methane and carbon dioxide. Modern UK landfills capture and use much of the methane gas as a fuel. But some methane escapes and is emitted to the atmosphere. Methane is an important greenhouse gas and controls on methane emissions are a part of international and national strategies to limit climate change. Better estimates of methane emissions from landfills and other similar sources would allow the UK to improve the quantification and control of greenhouse gas emissions.

Area sources are a key contributor to overall greenhouse gas emissions but present a particular challenge to emission measurement techniques due to the heterogeneous nature of the sources. A new Controlled Release Facility (CRF) has been developed that is able to recreate in the field both the distribution and rate of emissions seen in actual industrial applications. The results of a series of field validation experiments involving this facility and an infrared differential absorption Lidar (DIAL) facility are presented, which have demonstrated the capability of the CRF to generate controlled methane emissions from 1.8 kg/h to 11 kg/h with a typical expanded (k = 2) uncertainty of ~0.3 kg/h, and established that any underlying systematic uncertainty in the DIAL measurements across this range of methane emissions is less than 4% (or 0.2 kg/h).