Interrogating Emissions Using the Qube Platform

Author: Ben Montgomery, Andrew Walsh

TL;DR 

• Platform Overview: Qube’s platform provides continuous emissions monitoring, using wind data, gas concentration, and source identification algorithms to detect methane leaks. However, users must verify alerts, as the algorithm benefits from operational input to ensure accurate source identification. 

• Key Strategies for Verification: 

  • Wind Field Visualizations: Use wind direction data to cross-check if emissions originate from the identified source. 

  • Gas Concentration Roses: Visualize wind direction during detection to confirm the source. 

  • Heatmaps: Review long-term heatmaps to assess the probability of emission sources for better accuracy. 

• Continuous Improvement: Qube’s platform is constantly refined through collaboration with clients, helping to optimize emissions detection and reduce false identifications. 

---

At Qube, we’ve built a platform that clearly visualizes emissions data, continuously improving it to help our customers quickly detect and address methane leaks. While our continuous emissions monitoring system efficiently identifies potential leaks, it is important to note the underlying algorithms – though effective – are not flawless. These algorithms rely on data from known sources (e.g., tanks and flares), wind readings, and gas concentration levels. Although they generally perform well, the identified source may sometimes be inaccurate. That’s why it’s essential to interrogate each alert on the Qube platform to enhance field follow-ups. 

How Clients Use the Platform 

Most clients incorporate our software into their alert response workflow by setting a threshold for methane rate and leak duration. When this threshold is exceeded, the platform generates an alert and displays the most likely emissions source, prompting a field response. However, since the localization algorithm can occasionally misidentify the source, we recommend verifying each alert before taking action. This proactive approach minimizes time spent by field personnel inspecting incorrect sources. 

Years of close collaboration with our clients have driven us to continuously learn, innovate, and refine our approach. These partnerships have helped us develop three key strategies for more effective emissions interrogation. 

Key Strategies for Emissions Identification 

1. Wind Field Visualizations 

• Why It Helps: Each device is equipped with an anemometer, allowing for detailed wind field visualizations across the site. This adds a critical layer of analysis to the heat map, validating the identified source.  

• How to Do It:  

1. Open the raw device readings and gas concentration data for the emission event. 

2. Activate the wind-field animation on the platform. 

3. Identify gas concentration peaks and locate the device registering those peaks. 

4. Check the wind direction in the animation to confirm it was blowing toward the device from the identified source.  

5. Use this information to confirm whether the localization algorithm correctly identified the source. 

If the wind was blowing toward the device from the identified source, it’s a good indication the algorithm is correct.  

Wind Field Visualizations 

2. Use Gas Concentration Roses 

• Why This Helps: Gas concentration roses display the wind direction at a device when methane is detected. If the petals point toward the source during an emission, this suggests the algorithm performed correctly. 

• How To Do It:  

1. Turn on the gas concentration rose feature 

2. Zoom in on the emission of interest.  

3. Observe the direction of the petals to ensure they point toward the identified source. 

This feature typically works better under shorter timescales than longer ones. 

Gas Concentration Roses

3. Use the Emissions Source Heatmap 

• Why This Helps: Qube’s localization algorithm is constantly being optimized to better handle multiple source emissions. Currently, it calculates probabilities for each source but displays only the most likely one. By zooming out over a longer time scale, you can view a probability heat map for each potential source, improving source identification. 

• How to Do It:  

1. Zoom out on the time scale to view the data over a longer period. You effectively get a probability heat map of the sources at each site. 

2. Review the probability heat map that shows potential sources and their likelihood. 

3. Check for repeated emissions from the same equipment over time to confirm the accuracy of the algorithm. If an emission has an extended duration, it’s likely that the localization algorithm has pinpointed the correct equipment.

While an alert is generated almost instantly, zooming out accounts for the fact that the algorithm is usually correct over time, reducing the risk of relying solely on the single alert event. 

Emissions Source Heatmap 

By applying these techniques, you can more effectively verify emissions and ensure faster, more accurate responses to methane leaks. Additionally, consider using available facility data, such as SCADA systems, for further validation before deploying field teams. If you have any questions about interrogating emissions sources or need further support, feel free to contact the team at Qube Technologies.