Repsol Sinopec lidar camera trial advances methane emissions detection

Summary

Lidar technology proved accurate and instrumental to identifying and quantifying fugitive methane emissions at the Flotta Oil Terminal off the coast of Scotland.

Objective

Repsol Sinopec Resources UK Ltd. (Repsol Sinopec) wanted to identify and quantify methane emissions at the Flotta terminal site. Committed to lowering fugitive emissions, Repsol Sinopec initiated a trial using methane lidar camera* technology that uses tunable diode laser imaging, detection, and ranging to visualize and quantify methane emissions. The trial was jointly conducted by SLB and QLM Technology Ltd. The intent was to

detect any methane emissions at the oil terminal
enhance quantification of methane emissions in line with new emissions reporting standards
understand how straightforward deployment of a quantum gas lidar sensor can continuously and effectively monitor an entire large site
evaluate how methane emissions can be quickly detected, pinpointed, and quantified, even in a large and complex infrastructure
assess the use of methane sensing technology which could be deployed and stationed at site for longer term durations providing ongoing methane surveillance.

*Methane lidar camera is a licensed product of QLM Technology Ltd.

Results

Over the weeklong trial, two methane lidar sensing systems were deployed on platforms at heights of up to 20 m to facilitate measurements at numerous positions across the terminal. A thorough lidar scan of the terminal revealed a few methane emissions. However, the emission rates quantified by the lidar equipment were too small for detection by some conventional fugitive emission monitors.

A minor emission detected from a valve on pipework surrounding pressure control valves at ground level in the processing area. This emission was only observed for a short period of time, making it unlikely to be detected during a walkover survey. The left image shows a colorized methane plume on grayscale lidar image. The right image shows corresponding distances to solid objects, measured by the lidar simultaneously with the lidar gas imagery.

The diffuse emissions from an open-top effluent tank were able to have their flow rate quantified despite not appearing as a hot spot of methane concentration. Because the tank emissions are not from a point source, they appear as areas of higher and lower concentration across the image. The left image shows a colorized methane plume on grayscale lidar image. The right image shows corresponding distances to solid objects, measured by the lidar simultaneously with the lidar gas imagery.

The methane lidar systems achieved

successful identification and quantification of previously unknown minor emissions, all below regulatory reportable limits
characterization of highly intermittent emissions that would be difficult to identify and quantify during periodic walkover surveys
detection, localization, and quantification of point-source emissions and wide-area diffuse emissions
novel, custom mounting of the camera at the Flotta terminal
confirmation that most of the site was not emitting.

The bottom line

Technology performance was proved on a live, real-world facility.
Methane emissions, once pinpointed, provided Repsol Sinopec the data to be able to remediate emissions in priority according to size, safety, or maintenance concerns and also to compare top-down with bottom-up calculations.
Emissions at the Flotta terminal were readily detected and quantified by the technology, even for emissions too small for some conventional detection methods. The detailed information provided by the lidar equipment could be used to enable Repsol Sinopec to further reduce emissions.
The trial demonstrated that large, complex facilities such as the Flotta terminal can be continuously monitored for methane emissions using strategically positioned lidar equipment.

“Repsol Sinopec is committed to accurately measuring and quantifying our methane emissions and eager to assist in the development and trialing of new technologies in this area. We were delighted to host the successful trial of the methane lidar sensing system at Flotta terminal. Not only, we believe, did the trial provide QLM Technology Ltd. and SLB with valuable information, but the results gained provided ourselves with detail on top-down methane emissions, and also afforded further reassurance that we are operating the Flotta terminal in a manner that prioritises the safety of our people and the environment.“

Catherine Sherwin, Technology Lead, Repsol Sinopec Resources