From a Traditional to Modern Methane Gas Detector Strategy
According to the Environmental Protection Agency (EPA), methane, the primary component of natural gas, accounts for over 10% of all greenhouse gasses emitted in the United States. The biggest emitter of methane are the natural gas and petroleum industries which account for 32% of methane released into the atmosphere each year. Much of that 32% comes from leaks within the system that are not always picked up by a traditional methane gas detector strategy.
With methane being linked to over a million premature deaths per year and having a global warming potential 84 times higher than CO2 over the next 20 years, detecting methane leaks both upstream and midstream is more necessary than ever. Unfortunately, many operators still only rely on outdated monitoring systems such optical gas imaging (OGI) whose effectiveness is highly dependent on the equipment used and the expertise of the surveyor. However, there are modern methods of methane detection that, when coupled with traditional methods, can have a significant impact on how quickly a leak can be detected.
What are the Traditional Methane Gas Detector Methods?
First promoted by the EPA in 1981 and later codified into state and federal law, Method 21, or M21, was the primary strategy for detecting methane leaks for many years. However, while it is considered relatively precise, M21 has shown to be an incredibly resource-intensive process. Because it requires the inspectors to physically touch, document, and inspect each leak, on average, an experienced inspector will only be able to monitor around 300 valves per a day. With a single plant or refinery containing thousands of valves, along with connectors and pumps, relying on M21 as the only means of detection would require each location to have an entire team of inspectors to monitor for leaks.
To overcome the limitations that M21 posed, optical gas imaging was developed. As the only EPA-approved alternative to M21, OGI requires surveyors to use a highly specialized thermal infrared camera as a methane gas detector. The camera, which uses a specialized spectral filter to filter to the 3.2 to 3.4 μm spectra band where hydrocarbons are visible, is able to visualize the typically invisible gas. This has been shown by studies to detect leaks 9 times faster than the equivalent M21 method. Because of its effectiveness and speed, OGI has become the primary leak detection and repair method for managing methane and other volatile organic compounds (VOC) in the oil and gas industry.
How Effective is OGI?
Because of the advantages of OGI, it has been considered to be the most efficient and effective methane gas detector method in use. However, while OGI can be very effective in detecting methane leaks, a study released in 2020 showed its effectiveness was highly dependent on the experience level of the surveyor. An experienced surveyor, the study showed, was more likely to use multiple viewpoints or make various adjustments that improved their leak detection rate.
Surveyor experience isn’t the only factor that determines how effective OGI can be; things like air turbulence, equipment quality, or even equipment settings can have a significant impact on its success. On top of this, OGI effectiveness is also reliant on surveys being conducted at oil and gas infrastructure such as compressor stations, well heads, boosting stations, refineries, processing plants, and distribution facilities on a regular basis. While the EPA released a regulation in 2016 recommending that surveys be conducted quarterly or bi-annually, this leaves a lot of time in between for leaks to go undetected.
Building a Modern Methane Monitoring Strategy
With the intermittent nature of traditional methane gas detector methods, there are often months between surveys which allow any leaks that go undetected by methods such as M21 or OGI to pour methane into the atmosphere. The longer a leak goes undetected, the bigger the consequences. A study released in 2018 found that the U.S. oil and gas industry had a leak rate of 2.3% which dwarfed the EPA’s estimate of 1.4%. This leak rate resulted in over 13 million metric tons of methane being released into the atmosphere each year, accounting for an estimated $2 billion lost because of leaks. That amount of natural gas could fuel 10 million homes. These leaks not only cause immense damage to the earth’s ecosystems but also cost companies millions of dollars a year in lost profits.
Because of the weaknesses in intermittent monitoring, many oil and gas businesses are looking for a way to continuously monitor their systems for leaks so they can identify leaks as they occur. One continuous methane gas detection method involves using remote fixed point sensors in key locations to detect leaks. By using fixed point sensors, companies are able to more quickly detect and repair leaks early, reducing their overall environmental impact while increasing worker safety and profits.
Continuous monitoring isn’t the only benefit of using remote sensors to detect methane leaks. While traditional methods like OGI are reliant on things such as the weather, location of the sun, or the experience of the surveyor to ensure accurate results, remote monitoring is less susceptible to these limitations. Perhaps the largest concern is understanding wind speed and direction, but this data can be incorporated using an anemometer. You also have the benefit of gathering extensive historical data. Traditionally with OGI-only monitoring, access to data has been limited to what can be kept on an SD card. With remote sensors, this data can be stored locally or in the cloud, allowing for complete access to all the raw sensor data you have collected.
Mixing the New with the Old
Ensuring that your company is utilizing the most efficient and advanced methods for detecting methane gas leaks is important not only to your bottom line but to the future of our planet. However, it’s important to remember that no one method will be 100% effective, so it’s important to not put all of your eggs in one basket. Instead, by investing in both traditional methane gas detection methods, like OGI and M21, along with modern methods such as fixed point gas sensors, you can ensure that you are catching and fixing leaks as quickly as possible.
| Feature | EDG's Solution | Traditional OGI Handhelds |
|---|---|---|
| 24/7 Continuous Monitoring | Yes | No : OGI handhelds operate similarly to a camera, and only respond when a button is pressed or a trigger is pulled. |
| Immunity to Weather | Yes * | No : Devices using infrared technology are affected by moisture, which can result in false negatives when operating in windy conditions or during precipitation such as rain, snow, or fog |
| Consistent Measurements | Yes | No : OGI handhelds require manual operation, and are prone to directional inconsistencies. Not only must they be pointed directly at the source, but objects in the background such as the sun or reflections can adversely effect measurements. |
| 100% Remote Operation | Yes | No : OGI handhelds require a person to be on site |
| Accuracy | Yes | No : OGI handhelds require a person to be on site. Data is usually stored to an SD memory card, or similar removable device, and is not available to the team until it is uploaded to a centralized location. |
| Historical Access to Data | Yes | No : Handhelds are limited to the amount of data that can be stored on an SD memory card, or similar removable storage device. |
| * OGI surveyor recommended |
In order to build the right system that can help reduce the impact that leaks have on your business, you need the right tools. That’s where EDG comes in. From the hardware to software to the cloud infrastructure required to manage it all, EDG’s IoT solutions give you the tools you need to continuously monitor your oil and gas systems between scheduled surveys.
Learn more about EDG’s remote IoT monitoring solution or contact us today to start building your continuous monitoring platform.