مقاله انگلیسی رایگان در مورد زمین لرزه های اوکلاهما و قیمت نفت – الزویر ۲۰۱۸

Introduction

The surge in oil and gas supply due to hydraulic fracturing or ‘fracking’ has transformed markets and industries with wide ranging effects impacting coal burning facilities’ retirement dates and the follow-through on nuclear power plant additions. Interestingly enough, though, oil and gas are not the primary outputs of this type of production – water is. At the nascent stages of modern unconventional extraction, circa 2007, onshore oil and gas wells contributed as much as 17.82 billion barrels of ‘produced water’ (Clark and Veil, 2009). This water is later separated from the oil and gas and re-injected into disposal wells that are often at greater depth than the water originated.1 Alongside the surge in U.S. oil and gas supply, and the disposal of produced water, there has been a staggering increase in the amount of earthquakes felt in areas where waste-water injection is taking place (Ellsworth et al., 2015). Although wastewater-induced earthquakes have been felt in other areas,2 the state of Oklahoma has witnessed a striking increase in earthquake activity. Figure one shows just how unprecedented the change in earthquake activity has been. In the top panel all earthquakes from January 1 2000 through the end of 2009 are plotted; in the bottom panel the amount of earthquakes witnessed through 2016 are shown. Clearly, there has been a distinct increase over these seven years. In this paper I discuss the economic drivers of induced seismicity and further explore how effective regional authorities have been in reducing the amount of included earthquakes. Seismicity in Oklahoma serves as a very unique case because the current earthquake rate is 300 times higher than the historical rate (Weingarten, 2015). In fact, the seismicity rate in Oklahoma has increased so drastically that it is now more common to have a magnitude 3.0 or larger earthquake in a single day than in entire years prior to 2008. Specifically, Weingarten (2015) shows that the rate of magnitude 3.0+ earthquakes was 11 2 per year prior to 2008, and 21 2 magnitude 3.0 + earthquakes per day after 2008. Linking now to the amount of produced water, the advent of hydraulic fracturing has significantly increased the amount of disposal because the targeted formations often have a large amount of ‘associated’ water that is high in salinity and is brought to the surface as a bi-product. For example, Nicot et al. (2014) find that there was a five fold increase in produced water disposal in the Barnett shale between 2000 and 2011 – from 8.8 thousand acre feet per year to 45.7 thousand acre feet per year. In Oklahoma, approximately 849 million barrels3 of produced water per month were injected into disposal wells at the beginning of the fracking boom. By 2014 this amount had grown to 1.54 billion barrels per month. For comparison, produced water in the state of Texas increased from 33.8 million barrels per month in 2007–۸۱٫۱ million barrels per month in 2014 (Kuchment and Kuchment ()). For context, this means that nearly 19 times more produced water was injected within Oklahoma than Texas; even though Texas has more than three times the land area.