Lance Christensen, NASA / Jet Propulsion Laboratory (California Institute of Technology)
Ken Whitehead and Shahab Moeini, SAIT
June 2018
Executive Summary
Researchers from SAIT and NASA’s Jet Propulsion Laboratory (JPL) have been involved in a study looking at the use of NASA’s Open Path Laser Spectrometer (OPLS) mounted on an Unmanned Aerial Vehicle (UAV) for detecting fugitive emissions of methane in an active oil and gas production facility, located in the Drayton Valley area of Alberta
Researchers visited the study site in August 2017, October 2017, and March 2018, and carried out a series of flights for leak detection and emissions quantification on all three dates. The first field campaign took place on August the 30th, 2017. A total of four science flights were carried out, with the OPLS being flown on a DJI M600 UAV platform. The first two flights were used for leak detection, and were able to isolate the two major onsite leaks, which originated from storage tanks at the southern end of the site. The third flight was used for flux quantification, and involved flying back and forth at 5 m altitude increments to define a flux plane. The aggregate flux for both leaks was estimated to be 12.5 ± 6.5 cubic metres per hour (CMH). The final flight was used to test the range of detection. Significantly elevated levels of methane were detected at over 250 m from the source.
The second field campaign took place on the 19th of October, with five scientific flights being carried out. The OPLS was mounted on a DJI M200 UAV platform. The first four flights were designed to look for methane leaks, with investigations focusing on the storage tanks, and on the outbuildings to the north of the tanks. The same two leaks from the storage tanks were once again quickly identified from the third flight, in which the UAV was flown downwind of the tanks at multiple elevations. The second and fourth flights focused on the outbuildings to the north of the tanks. Three small leaks were detected from different buildings, and these were verified by the representative of the Alberta Energy Regulator (AER). The final flight was used for flux quantification, with the UAV being flown back and forth at 5 m altitude increments to define a flux plane. The aggregate flux on this occasion was determined to be 13.2 ± 4.9 CMH, which is similar to the estimate from the August survey.
The third field campaign took place on the 20th of March, and used the OPLS mounted on a DJI M600 platform. Temperatures were cool, but remained above freezing throughout the day, averaging 3.5°C, with snow on the ground. A total of five surveys were carried out, with the initial flight providing little in the way of useful information, due to light and variable wind conditions. The second flight was a reconnaissance flight to identify where the main leaks were located. Attempts to complete a flux quantification during flight 3 were unsuccessful, due to poor wind conditions. The fourth survey involved carrying the OPLS around the site to investigate potential leak locations in more detail. A number of small leaks were identified in the outbuildings to the north of the storage tanks. These were confirmed by the representative of the AER. The final flight investigated emissions from the flare stack, while it was active. Methane spikes, believed to be due to flaring were identified during this flight.
The results from this study are promising and suggest that combination of using the OPLS, mounted on a UAV, has the potential to be an effective tool for detecting fugitive methane emissions from oil and gas facilities. The study also highlighted the important role that weather conditions play in successful leak detection and flux determination. This was particularly evident during the March 2018 campaign, when light and variable winds prevented flux estimations from being made.
# 17-ARPC-02