There’s a seemingly endless array of up-to-the-minute research programs taking place at the Bureau of Economic Geology in the Jackson School of Geoscience at the University of Texas, Austin.
Among its many projects, the BEG is pioneering lidar (light detection and ranging) remote sensing technology to be a valuable tool in the rapid quantitative characterization of outcrop geology.
The technology is being used to investigate both clastic and carbonate systems.
There’s more – much more – as the researchers venture still further into the esoteric realm.
“The newest advances we’ve been doing a lot of research with lately include small UAVs (unmanned aerial vehicle), or drones,” said AAPG member Chris Zahm, research associate with the Reservoir Characterization Research Laboratory (RCRL).
The RCRL is an industrial associates program comprised of 30 oil and gas companies that support the research.
Zahm noted that AAPG member Charles Kerans, the principal investigator of the RCRL since its inception in 1987, has been instrumental in bringing both ground-based and airborne lidar, along with the UAV technology into practical and useful forms for over a decade.
“With lidar you send out an active signal, a laser, toward the outcrop, and it has a reflectivity back to a scanner and tells the scanner exactly how far away the outcrop is,” Zahm noted.
“Right now, we’re using our drones to take photos,” he said. “The science and software exist that if you take a photo of some object from multiple locations, you have the ability to create a 3-D model from those photos.”
He noted that this is actually photogrammetry, which is a more-than-100-year-old science, commonly used for the development of topographic maps.
The game plan using the drones is to have significant overlapping of the photos.
“If we take a drone and fly it around over a particular outcrop, we can take a picture from multiple angles and develop a quantifiable 3-D image of that outcrop,” Zahm said. “This has been an exciting new frontier we’ve been dealing with in the last 18 months.
“I find it to be even more attractive to geologists because it inherently puts together the photograph as you might see (the outcrop) if hovering directly over it – kind of like getting a bird’s eye view so to speak,” he emphasized.
“It can be very realistic,” he said. “You can look at the outcrop from many different perspectives, and it can be quantified.”
Zahm noted that the UAV enables them to pre-program a flight pattern to be very systematic in how the overlaps work. This beats the heck out of trying to snap overlapping photos through the window of a helicopter.
When conducting a robotic program via the UAV, it acquires a 65 to 75 percent overlap on each picture given that it’s pre-programmed to do so, and this gives a higher accuracy or precision to the resulting model.
Using the pre-programmed flight path enables sufficient overlap to be recorded while covering the entire area of interest over the outcrop.
“We get a very high resolution photo looking vertically down on the outcrops,” Zahm said. “You can’t acquire that level of photograph from commercially available satellite pictures.
“In our photos, we’re talking about centimeter to millimeter resolution, which is very different.”
Zahm noted that the UAVs the RCRL group uses measure 24 to 30 inches wide. They can carry them to the field and deploy them with the cameras.
“It’s sort of like taking a robotic helicopter like your kids play with and making it a useful tool in the field,” he jested.
He is a true believer in the many positive applications for drones.
“When I talk about drones to people, they tend to think about the military aspects, and it’s kind of a negative connotation,” he noted. “We have to remember that there are benefits as well, and it can be a very friendly technology.
“The application of UAV technology definitely has improved the ease and quality of reservoir characterization,” Zahm declared.
To further emphasize the friendly-use aspects, he mentioned a recent situation where a research partner flew a drone over a gathering of UT alums. This resulted in one of the attendees deciding on the spot to use a drone to assess a property of interest to him.
Current RCRL applications of UAVs include:
- Turks and Caicos (Bahamas) – West Caicos (facies and fracture mapping).
- China – Permo-Triassic grainstones.
- Lewis Canyon (Texas) – Fault-related fractures.
- Canyon Lake (Texas) – Fault-related fractures.