January 2017, Vol. 244, No. 1
Features
How EPA Regulations Change Ways We Look at Gas Leaks
Last year the Environmental Protection Agency (EPA) published Regulation 40 CFL, Part 60, Sub-part OOOOa, commonly known as QuadOa, and finally brought optical gas imaging (OGI) firmly into the mainstream. This presented a major shift in the way that emission detection from gas leaks is regulated, and the technology that can be used.
Detecting and acting on gas leaks is naturally a major concern for operators and a challenging problem to address. OGI technology started to play a role about 10 years ago when companies began using it to reduce the harm caused by leaks to public health, the environment and corporate profits. At the time, the EPA had a series of robust protocols concerning gas leak detection, known as Method 21, which relied on “sniffers” – devices that use a physical or chemical reaction to identify the presence of leaked gas.
Sniffers have proved to be a reliable method of detecting the presence of leaking gas in the atmosphere by measuring its concentration in parts per million (ppm) from an air sample. If gas is present where it shouldn’t be, a sniffer will pick it up. But there are some limitations to sniffer technology.
Method 21 is labor-intensive; operators have to cover thousands of components and measure gas concentrations for each one. However, sniffers can only detect gas in extremely close proximity to components being inspected. As a result, leaks from unexpected or difficult-to-reach sources can go undetected.
Sniffers are not designed to detect the specific source of a leak which may result in delays or failures in repair and further losses. What’s more, sniffers require routine calibration and are prone to “poisoning,” which hampers the sensor’s active sites when exposed to concentrations beyond a certain level.
Furthermore, since sniffers measure concentrations and not flow rates, in order to quantify the greenhouse gas (GHG) environmental effect of a leak based on the parts per million (ppm) reading, calculation formulas are required. These formulas use complex empirical and statistical data to translate ppm readings to tons of CO-2 equivalent figures.
This is where OGI comes to the fore. By using an infrared thermal-imaging camera that visualizes hydrocarbons based on unique electro-magnetic radiation absorption patterns, OGI enables operatives to observe the plume of leaking gas. They can then see the gas through the camera, find the source of the leak with pinpoint accuracy and take swift mitigating action – even when the ppm rate is relatively low. An OGI camera can also record video, thus giving verifiable proof a particular has been repaired.
Since 2008, OGI devices have been used as an alternative to sniffers in remote or hazardous locations, as well as for non-scheduled inspections. In 2011, EPA recognized for the first time that OGI technology offered certain advantages, and updated its written regulations to say that it could be used as an alternative work practice (AWP) to Method 21 sniffers.
However, EPA only permitted the use of OGI for three out of four routine quarterly inspections, with sniffers being mandatory for the fourth. This particular ruling slowed down the adoption of OGI since it required operators to invest in and deploy an additional technology.
The new legislation, which took effect last August and will become mandatory by June, changes that. EPA recognized OGI as the best system for reducing (BSER) hydrocarbon emissions in the midstream oil and gas industry as well as upstream. Under the terms of QuadOa, OGI technology is permissible at well sites and compressor stations in all routine inspections, whether quarterly or annually.
The regulation does allow for continued use of Method 21 sniffers, but the supporting documents show inspections are up to four times faster than Method 21, and therefore more cost-effective. With a new regulatory framework in place, the stage is set for widespread adoption of OGI.
But what can companies interested in reducing costs and increasing effectiveness do to prepare for the June deadline? There are three aspects that operators should consider in OGI technology:
- Compliance with OOOOa requirements. First is to look for appropriately certified and compliant tools. In addition to identifying OGI as the best system to use for reducing emissions, the regulations specifications specify what the technology should be able to do.
Operators must ensure the equipment they choose is capable of detecting hydrocarbons by working selectively in the correct spectral band (OGI cameras that use a cooled MCT detector with a spectral band of 3.2-3.4 um will meet this requirement).
QuadOa requires a sensitive OGI camera able to detect a small leak comprising 50% methane and 50% propane in a concentration of 10,000 ppm. Any technology chosen must have appropriate certifications and come from certified manufacturers that can verify compliance with the new regulations.
Operators should also check to see the OGI camera can record, store and retrieve video of the inspection process, including date, time and GPS location as evidence for future regulatory audits.
- Environmental suitability. If OGI is the standard tool for routine inspections, it has to be suitable for the unique challenges posed by the oil and gas operating environment. In particular, it has to withstand the harsh conditions typically found in midstream and upstream operations.
Operators should look for camera equipment certified for hazardous locations with UL Class 1, Div. 2 certification. Not only will this ensure the equipment is appropriate for the safety requirements of the environment, it avoids having to go through the process of securing an individual “hot permit” for every use.
- Daily operation. The new regulations represent a significant step up in the use of OGI technology as it becomes a routine method rather than a specialized tool. Therefore, it is important to consider that the equipment will be used on a much more frequent basis, in all weather conditions and during long hours of operation.
The design and ergonomics of the equipment should also be taken into account. Is it made from appropriate materials to withstand the wear and tear of day-in, day-out field use? Is it sealed against dust and water to enable use in those conditions? Is it light enough to be portable? Can it be easily be operated with gloves? Does it provide glare protection and image magnification for eyeglass wearers? Is the camera suitable for long hours of continuous inspection? Since using one eye can induce dizziness, fatigue and strain, is it equipped with a large LCD display that allows operators to observe naturally with both eyes open?
The new regulations come as operators are driving cost efficiencies throughout their businesses to maximize production. Choosing the right technologies enables them to meet these demands while keeping people and the environment safe by minimizing costs from lost product, shortening the time to detect and repair critical assets, reducing the risk of potential fines and damage to reputation.
On Dec. 8, OPGAL received independent verification for its Optical Gas Imaging (OGI) technology in relation to the QuadOa. EyeCGas was independently tested at the UK’s National Physical Laboratory, and was proven compliant with the regulation requirements.
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