Locating orphan oil and gas wells is the top priority of my work with the U.S. Fish and Wildlife Service. Orphan wells are wells that lack a known owner and must be plugged and/or remediated by federal or state government agencies. Wells can become orphaned either from historically poor record keeping or poor location accuracy, or through bankruptcy of the responsible company. Although surety bonds are purchased prior to developing wells, the money provided by the bonds are insufficient for remediating these wells. I utilize remote sensing technologies to identify these wells on wildlife refuge land.

Due to the uncertainty of the locations of orphan wells, new techniques need to be developed to find them. Otherwise, you’re left with walking hundreds of acres with short range devices, like metal detectors, scouring for wells. My work involves using airborne light detection and ranging (lidar) to locate wells based on their ground characteristics. Lidar relies on light pulses to map out the heights of objects. After processing lidar data, I obtain an image of an entire area, in this case, the Trinity River National Wildlife Refuge. The imagery is then reviewed to find features that resemble well features, see below.

The objects marked in the squares were expected to be the location of an orphan oil and/or gas well. This procedure was done for all National Wildlife Refuges in the Southwest Region of the U.S. Fish and Wildlife.

However, this is just one step in my workflow. Now that potential locations for wells have been found, we need to verify that those locations have well infrastructure. The image below shows the orphan well we found at the location in the first image.

Although this process may seem simple, many features identified from the lidar could be dirt mounds or stock ponds that are not associated with wells. Unfortunately, ground verification of these features can be a very time consuming process with locations often being inaccessible by foot due to flooding or heavy vegetation for most of the year. However, having a narrowly defined list of sites to visit, an aerial view of the sites, and a means of navigating to these sites makes searching for orphaned wells a lot more efficient then searching solely on foot.