Characterizing and modeling environmental emergency of unconventional oil and gas spills in the USA: Life-year versus spill factors

摘要

Significantly reducing consumers' electric bills and producing more jobs in USA, the remarkable growth of unconventional oil and gas (UOG) especially shale gas production in the last decade has made an impressive accomplishment. However, threatening the environment caused by UOG spills, UOG has caused enormous concerns about public health risks, there is minimized research examining the UOG spills' causal mechanism and its spatial and temporal characteristics, which could play pivotal roles in risk control and environmental protection. Using two states Colorado (CO) and New Mexico (NM) in the USA with detailed UOG spill observations from 2005 to 2014, this study designs multi-categorical statistical tests and models to examine the factors that characterize UOG spills including spilled volume, life-year, cause, pathway, and spilled material. The ANOVA of spilled volumes across life-years has a p values 0.517, and hence the differences in spilled volumes among life-years are not significant in both CO or NM, but spilled materials are significantly between life-year 0 and other life-years with a p-value 0.0001. Based on a series of Poisson regression models for the association between pathway and spilled material and the conditional association given causal mechanism, the Chi-squared tests have p-values less than 0.00001, which shows both joint dependence and conditional dependence of pathway and spilled materials by controlling causal factors are significant in both CO and NM. Furthermore, spatiotemporal hot and cold spots of UOG spills are significant in CO, but they are not significant at p-value 0.01 in NM. This study is the first time to analyze and model the multivariate factors of UOG spills, which provides the first-hand insight to the characteristics of spills and to the monitoring and mitigation of potential risks in the lifetime of UOG operations. (C) 2019 Elsevier Ltd. All rights reserved.