5 Questions to Ask When Evaluating Methane Emissions Detection Technologies

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The Questions You Need to Ask Your Methane Detection Technology Partner

There is a lot to consider when evaluating methane emissions detection technologies and providers. From aerial methods to those on the ground, careful thought must go into your choice.  

It is difficult to know what to ask technology providers if you don’t do this every day. To help get conversations started, we’ve put together a list of five important questions to ask when weighing various methane detection technologies to meet your leak detection and repair (LDAR) and sustainability goals. These questions will help you better understand what performance you should expect, confirm the products you will receive from the scans and equip yourself to weigh benefits and drawbacks between technologies. For perspective, we’ve included how Bridger Photonics would answer each of these questions. 

1. What is Your Detection Sensitivity, and How Does it Relate to Minimum Detection Limit? 

Detection sensitivity refers to the size of a leak (i.e. the emission rate, or how much of a gas flows over time) that can be detected by a given technology. Detection sensitivity is a critical indicator of the effectiveness of methane emission detection technology for achieving your sustainability goals. Yet detection sensitivity can be stated in so many ways, it can be incredibly confusing. It’s important to understand the different ways detection sensitivity can be stated so different technologies can be compared “apples to apples”. 

The first confusing aspect of detection sensitivity is that so many different units are used (e.g. scfh, Mscfd, kg/hr, m³/d, l/m). Our recommendation is to pick units that you like and make the prospective solution provider put their detection sensitivity into those units.  Or, here’s a handy site for converting units. However, even with units that you like, a single detection sensitivity number is not enough.  There are two more critical pieces of information you need to make a fair comparison.

First, detection events are statistical, so in addition to the detection sensitivity number you need to know the probability of detection (PoD) for that detection sensitivity.  In other words, how likely is it that a technology will catch a leak at the stated detection sensitivity?  Will it catch one out of one hundred (1% PoD) leaks that size? Will the technology catch half of the leaks of that size (50% PoD)? Or is the solution provider confident of detecting an emission at their stated detection sensitivity (>90% PoD). At Bridger Photonics, we prefer >90% PoD because it imparts confidence that we will catch a leak of a given size. Sure, we’ll catch leaks that are even smaller, but the probability decreases with smaller leaks. You may also come across the term “minimum detection limit”. This can cause confusion because “minimum” can imply (often without intent) the smallest leak that a detection technology can catch, even if there’s only a very small probability of detecting that leak (e.g. 1% PoD). For this reason, including an explicit PoD is essential for understanding how the technology will perform.  

The second critical piece of additional information you need is the operational conditions under which the technology solution is expected to achieve the stated detection sensitivity and PoD. Should you expect this performance under “typical” conditions or under “all” conditions?  Or will the solution only work under “idealized” conditions that don’t represent the real world? 

How Would Bridger Answer?  

In the production sector, Gas Mapping LiDAR™ achieves a detection sensitivity of 3 kg/hr (or 161 scfh) with >90% PoD in “typical” conditions. And as a “backstop”, we won’t operate in conditions if we can’t achieve a detection sensitivity of 10 kg/hr with >90% PoD (“all” conditions).  Interestingly, we chose this detection sensitivity and PoD level because it coincides with capturing an estimated 90%+ of the total emissions in typical production basins.

We qualify our sensors under “typical” conditions.  To help ensure approval of Gas Mapping LiDAR under existing and impending regulations, we can also provide a “backstop” for “all” conditions. This gives our clients (and regulators) confidence that we will only operate in conditions under which we can achieve the “backstop” detection sensitivity.

Moreover, we can go more or less sensitive depending on specific client or industry sector needs. For the distribution sector, where we are scanning entire metropolitan regions, we currently achieve 0.2 kg/hr (10.7 scfh) with 50% PoD (assuming unobstructed view) and our second-generation sensor version is predicted to achieve that detection sensitivity with >90% PoD.
 

2. What are Your Capabilities to Flag Emission Events as Persistent or Intermittent? 

A technology that differentiates between persistent and intermittent emissions provides important context to a detection event. This data often helps operators determine whether or not they should expect to find a repair event corresponding to a given emission. Persistent emissions often correspond to fugitive emissions that require repair. On the other hand, intermittent emissions often correspond to normal operating process emissions.  Both are important for understanding an emissions inventory and for reducing emissions, but the former often requires a repair crew, while the latter may be addressed with planned retrofits and infrastructure upgrades.

How Would Bridger Answer?  

Bridger Photonics provides “flags” in our data products, identifying detected emissions as persistent or intermittent. We determine persistence by re-scanning detection events on a subsequent day to assess whether or not they persist, along with further analysis by our data processing specialists.  

3. Does Your Technology Quantify Emission Rates?  

Detecting emissions is often the first goal, but quantifying emissions can provide a baseline of your overall methane emissions inventory and enable tracking of improvements resulting from your emissions reduction initiatives. Moreover, emission rate quantification allows operators to address the largest leaks first, which improves both safety and emissions reduction. Additionally, if the technology has sufficient spatial resolution to associate emission events with pieces of equipment on a site, quantification can uncover trends like identifying what equipment types are most significant contributors to the overall emissions profile for a set of assets. This information can then be used to develop an effective and economical emissions reduction plan. Finally, the ability to accurately measure and quantify methane emissions is becoming increasingly important for certification and differentiated natural gas programs. 

How Would Bridger Answer?  

Bridger Photonics quantifies methane emission rates from the air with industry-leading accuracy. Gas Mapping LiDAR’s quantification capabilities have been tested extensively by third parties including scientists and industry organizations.  Our team has also conducted internal studies showing that Gas Mapping LiDAR achieves better than 10% uncertainty when many emitters are included in an inventory. Read the full whitepaper here. Bridger’s ability to detect, pinpoint, and quantify methane emissions allows oil and gas operators to achieve even the most stringent certification levels across the entire supply chain.

4. How Accurately Do You Pinpoint Methane Emission Sources?  

Simply knowing that emissions are coming from a site is inadequate for efficient repairs with ground crews. Pinpointing emission sources before site visits ensures crews know which piece of equipment needs attention and helps identify whether the solution should be handled by operations (e.g. unlit flare or open thief hatch), or repair crews (e.g. leaking flange). 

How Would Bridger Answer?  

Gas Mapping LiDAR data includes GPS coordinates of each detected emission source with a typical uncertainty of better than two meters in all three dimensions. Our skilled data scientists analyze the data acquired by our sensors, classifying and quantifying emissions associated with specific equipment. We provide actionable reports from the aerial scans that include, in additional to the GPS pin of each leak source, high-resolution aerial imagery of the emissions and digital photographic imagery of the facility at the time of the scan. You receive actionable data about the leak size, persistence, and location to inform decisions about repair priority.

5. When and How Will I Receive My Methane Emissions Data?   

Timeliness of alerts and emission data is essential for operational efficiency and to address serious emissions quickly. Consider the information you are hoping to receive and what your plan of action will be from the data:  

• Will your team be notified of large detection events quickly, or will you have to wait for a full report?  
• Will you receive large amounts of raw data to parse through, or will it be organized and actionable? 
• Will your entire operations, air permitting, EHS, and ground crew teams need to download a custom app to receive your emissions data?  
• Will the data delivered be in a format compatible with your systems?  

By knowing how and when you’ll receive your emissions data, you can better plan how to use and disseminate it across your organization in the most useful and efficient way possible.  

How Would Bridger Answer?   
Bridger Photonics provides data at three different points: 

• Immediate alerts for significant emissions above a pre-determined threshold with our clients.   
• A Safety Report is issued the day following each scan, which includes geo-registered gas plume imagery with maximum path-integrated concentration, along with the date and time of detection. 
• Processed Reports containing the fully processed data products delivered 5 to 10 business days after the completion of data acquisition.  

Bridger captures an immense amount of information about each emission and distills it into useful and actionable data for our clients. Reports are delivered in the form of a GIS file (e.g. for ArcGIS, or GoogleEarth), Excel spreadsheet, and/or PDF.