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

Steven L Garman

doi:10.1007/s10666-017-9559-1

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.

Highlights

Energy development within sagebrush (Artemisia spp.) landscapes has emerged as a topical conservation issue [1]
An underlying assumption of this analysis is that the proven use of directional drilling for economic recovery of conventional and coal-bed natural gas [37] applies to the Atlantic Rim Project Area (ARPA)
Mean surface disturbance of pads decreased proportional to pad numbers until scenario 5

Summary

Introduction

Energy development within sagebrush (Artemisia spp.) landscapes has emerged as a topical conservation issue [1]. In the past three decades, an emphasis on domestic fossil-fuel production accelerated the development of onshore federal mineral estates in sagebrush landscapes supporting some of the highest densities of sagebrushobligate species [4, 8]. The removal of habitat by oil and gas infrastructure, behavioral avoidance of infrastructure by wildlife species, and infrastructure-mediated impacts to survival and reproduction due to altered predator [9] and disease dynamics [10] further fragmented sagebrush habitat [11] and elevated risks to resident wildlife populations [1, 12,13,14]. To help meet energy demands, growth in natural gas production is anticipated in the Intermountain West [16] with development likely concentrated in the geologic basins

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Results

Conclusion