Digital Representation of Oil and Natural Gas Well Pad Scars in Southwest Wyoming

Abstract

The recent proliferation of oil and natural gas energy development in southwest Wyoming has stimulated the need to understand wildlife responses to this development. Central to many wildlife assessments is the use of geospatial methods that rely on digital representation of energy infrastructure. Surface disturbance of the well pad scars associated with oil and natural gas extraction has been an important but unavailable infrastructure layer. To provide a digital baseline of this surface disturbance, we extracted visible oil and gas well pad scars from 1-meter National Agriculture Imagery Program imagery (NAIP) acquired in 2009 for a 7.7 million-hectare region of southwest Wyoming. Scars include the pad area where wellheads, pumps, and storage facilities reside, and the surrounding area that was scraped and denuded of vegetation during the establishment of the pad. Scars containing tanks, compressors, and the storage of oil and gas related equipment, and produced-water ponds were also collected on occasion. Our extraction method was a two-step process starting with automated extraction followed by manual inspection and clean up. We used available well-point information to guide manual clean up and to derive estimates of year of origin and duration of activity on a pad scar. We also derived estimates of the proportion of non-vegetated area on a scar using a Normalized Difference Vegetation Index derived using 1-meter NAIP imagery. We extracted 16,973 pad scars of which 15,318 were oil and gas well pads. Digital representation of pad scars along with time-stamps of activity and estimates of non-vegetated area provides important baseline (circa 2009) data for assessments of wildlife responses, land-use trends, and disturbance-mediated pattern assessments.

First posted February 19, 2014