“The FLIR camera utilizes technology that lets you see the leak,” said DOGGR Engineering Geologist Andrew Lush. “In terms of us communicating with operators and the public, there’s nothing like a picture.”
The Department of Conservation continues to modernize technology to improve oversight of California’s oil and gas industry. One relatively new acquisition has been Forward-Looking InfraRed (FLIR) cameras that aid field inspectors and operators in the detection of methane leaks.
The presence of methane can be missed because it is an invisible gas and doesn’t have an odor by itself. However, when combined with oxygen in the air and heat, methane can be combustible, and is a known contributor to atmospheric warming.
The FLIR cameras−four have been purchased for the Division of Oil, Gas, and Geothermal Resources (DOGGR)−record videos in visible light, infrared light, and in an optical gas imaging (methane detection) mode. Methane and other hydrocarbons absorb infrared wavelengths and the cameras’ filtering technology “sees” those wavelengths. Other camera features include digital zoom capability, two lenses, and the functionality to record in six color “palettes.”
DOGGR Engineering Geologist Andrew Lush says the camera’s most useful function for detecting methane emissions is the High-Sensitivity Mode (HSM) for comparing successive frames of video.
If there are no changes in the shot scene, overlays of the frames should be a neutral background as the elements are “canceled” out in HSM. If that isn’t the case, it implies something has changed from one frame to another. That something could be movement from a methane leak. HSM increases light sensitivity by more than 500 percent.
“The FLIR cameras make documentation and communication of leak locations much easier and efficient,” said Lush.
Operators monitor their facilities using gas emission “sniffer” sensors or laser detection devices but those methods have limitations, as methane dissipates very quickly at short distances away from a leak.
The FLIR cameras can detect concentrations of methane much less than 1 percent (or 10,000 parts per million) in the air and see leaks even smaller than a gas pilot light from short (and safe) distances. So, the cameras enable verification of visible leaks that the operator detects and potentially identifies others not seen by them.
According to Lush, the FLIR cameras have discerned several small leaks at wellheads in Northern District natural gas storage fields. In addition to repairing the leaks, operators must report emissions of a certain amount to the California Air Resources Board.
DOGGR has scheduled camera checks of the Northern District wellheads into their routine inspections several times a year.
Lush said the camera operators have generally found that at 10 to 15 feet, the cameras can show the entire wellhead to lend relational or environmental context to a suspected leak. They can focus tighter, such as on a valve joint or bolt, to show a leak’s emission point. Larger leaks can be documented from more than 100 feet (as flares or emissions from tanks and other facilities).
Each DOGGR district has a camera. DOGGR field inspectors and their supervisors have been trained and certified in the use of the cameras. Staff checks with well operators before accessing the wellheads.
Other expected uses for the cameras are to investigate potential leaks at production wells, production facilities, surface or buried pipelines, idle and abandoned wells, and for environmental field inspections.