A Simulation Framework for Assessing Physical and Wildlife Impacts of Oil and Gas Development Scenarios in Southwestern Wyoming

Abstract

Foreseeable natural gas development in southwestern Wyoming has the potential to increase sagebrush fragmentation and risks to resident wildlife species. The ability to balance future development with conservation goals, however, is enhanced by advances in directional-drilling technologies that use multiple wells per pad and produce less surface disturbance than conventional drilling methods. To evaluate the conservation potential of this technology, I developed an energy footprint model that simulates well, pad, and road patterns for oil and gas recovery options that vary in well types (vertical and directional) and number of wells per pad and use simulation results to quantify physical and wildlife-habitat impacts. I applied the model to assess tradeoffs among 10 conventional and directional-drilling scenarios in a natural gas field in southwestern Wyoming. Scenarios spanned a gradient in the number of vertical and directional wells, and in number of pads (2000 to 250), but all extracted the same amount of gas over a 15-year period. Reducing pad numbers with directional-drilling technology reduced surface disturbance area and impacts on spatially extensive habitats (48-96% of study area) such as sagebrush-obligate songbird habitat, elk winter range, and sagebrush core area. Impacts declined for spatially restricted mule deer migration corridors (24% of study area) and greater sage-grouse leks until energy infrastructure densities within corridors and near leks were similar to the initial landscape. Scenario simulations and tradeoff assessments such as illustrated in this study are intended to help decision-makers identify development designs that best achieve both energy and conservation goals.

Greater sage-grouse science (2015–17)—Synthesis and potential management implications

“…These results, and those presented by Gamo and Beck (2017), support the conclusion that overall the Wyoming Governor's Executive Order is helping safeguard critical sagegrouse habitats at the State-wide scale. Other recent research is consistent with past findings that the implementation of certain mitigation techniques or design features for oil and gas operations may be beneficial in reducing, but not eliminating, adverse effects to sage-grouse (Fedy and others, 2015a;Garman, 2017;Holloran and others, 2015;Kirol and others, 2015b).…”

Influences of potential oil and gas development and future climate on Sage‐grouse declines and redistribution

“…We used a spatially explicit oil and gas footprint model (Garman ) to simulate realistic spatial patterns of future oil and gas development under alternative development intensity scenarios. The model annually added new well pads and access roads to existing oil and gas infrastructure, cumulating active infrastructure over 50 yr (2012–2062).…”

“…Both energy development and climate-driven conversion of sagebrush vegetation (Artemesia spp.) are expected to affect Greater Sage-grouse (hereafter Sagegrouse) populations over the next 50 yr (Homer et al 2015, Garman 2018), yet we know little about their potential magnitudes and combinatory influences on populations. Southwest Wyoming (Wyoming Landscape Conservation Initiative area covering five counties, hereafter SW WY) hosts a large population of Sage-grouse that depend on sagebrush landscapes for their seasonal habitat needs.…”

“…Oil and gas development is expected to expand in the coming decades, increasing its footprint on sagebrush habitat (Copeland et al. , Garman ). Climate‐induced changes in vegetation are expected to cause the loss of sagebrush, increases in bare ground, and reductions in shrub, litter, and herbaceous vegetation in the next half‐century (Homer et al.…”

Multi-Resource Analysis—Methodology and synthesis

“…Related modeling efforts have demonstrated that much more detailed modeling of surface disturbances from energy development is feasible. Garman (2015Garman ( , 2018 describes an "energy footprint" model in which actual well pad and road networks from recent development in a region of interest are digitized and then sampled within a simulation framework to make more realistic predictions of what the surface disturbance for a given development buildout would look like on the ground. This computationally intensive approach provides fine-grained information that is likely to be more useful in detailed ecological modeling than simpler aggregated approaches.…”