TY - JOUR
T1 - Measuring methane emissions from abandoned and active oil and gas wells in West Virginia
AU - Riddick, Stuart N.
AU - Mauzerall, Denise Leonore
AU - Celia, Michael Anthony
AU - Kang, Mary
AU - Bressler, Kara
AU - Chu, Christopher
AU - Gum, Caleb D.
N1 - Funding Information:
The National Oceanic and Atmospheric Administration (Grant # AWD1004141 ) supported this research. We thank the Princeton Environmental Institute for funding for the undergraduate summer interns who helped with field work. Many thanks to the WV Department of Natural Resources, especially Chris Ryan, Delbert Vandevander (Stonewall Jackson WMA) and Jordan Stackpole (Lewis Wetzl WMA). Also, thanks to Mary Behling of the West Virginia Geological and Economic Survey, Jeremy Cross at Mountwood Park and West Virginians whose local knowledge was invaluable: Tom Berlin, April Keating, Kevin Campbell, Tim Higgins, Mirijana Beram, Christina and Wayne Woods, Beth Crowder and Mike Naylor. Thanks also to Neil Harris (Cranfield University) and Andrew Robinson (Cambridge University) for the provision of a gas chromatograph and their assistance with the instruments. At Princeton University, we thank: Christy Kaiser and Marrisa Webber for their help in the field, Peter Jaffe for access to the GC, Levi Golston and Jim McSpiritt for help with instruments and Sean Gallagher for his metal detector.
Publisher Copyright:
© 2018
PY - 2019/2/15
Y1 - 2019/2/15
N2 - Recent studies have reported methane (CH4) emissions from abandoned and active oil and gas infrastructure across the United States, where measured emissions show regional variability. To investigate similar phenomena in West Virginia, we measure and characterize emissions from abandoned and active conventional oil and gas wells. In addition, we reconcile divergent regional CH4 emissions estimates by comparing our West Virginia emissions estimates with those from other states in the United States. We find the CH4 emission factors from 112 plugged and 147 unplugged wells in West Virginia are 0.1 g CH4 h−1 and 3.2 g CH4 h−1, respectively. The highest emitting unplugged abandoned wells in WV are those most recently abandoned, with the mean emission of wells abandoned between 1993 and 2015 of 16 g CH4 h−1 compared to the mean of those abandoned before 1993 of 3 × 10−3 g CH4 h−1. Using field observations at a historic mining area as a proxy for state-wide drilling activity in the late 19th/early 20th century, we estimate the number of abandoned wells in WV at between 60,000 and 760,000 wells. Methane emission factors from active conventional wells were estimated at 138 g CH4 h−1. We did not find an emission pattern relating to age of wells or operator for active wells, however, the CH4 emission factor for active conventional wells was 7.5 times larger than the emission factor used by the EPA for conventional oil and gas wells. Our results suggest that well emission factors for active and abandoned wells can vary within the same geologic formation and may be affected by differences in state regulations. Therefore, accounting for state-level variations is critical for accuracy in greenhouse gas emissions inventories, which are used to guide emissions reduction strategies.
AB - Recent studies have reported methane (CH4) emissions from abandoned and active oil and gas infrastructure across the United States, where measured emissions show regional variability. To investigate similar phenomena in West Virginia, we measure and characterize emissions from abandoned and active conventional oil and gas wells. In addition, we reconcile divergent regional CH4 emissions estimates by comparing our West Virginia emissions estimates with those from other states in the United States. We find the CH4 emission factors from 112 plugged and 147 unplugged wells in West Virginia are 0.1 g CH4 h−1 and 3.2 g CH4 h−1, respectively. The highest emitting unplugged abandoned wells in WV are those most recently abandoned, with the mean emission of wells abandoned between 1993 and 2015 of 16 g CH4 h−1 compared to the mean of those abandoned before 1993 of 3 × 10−3 g CH4 h−1. Using field observations at a historic mining area as a proxy for state-wide drilling activity in the late 19th/early 20th century, we estimate the number of abandoned wells in WV at between 60,000 and 760,000 wells. Methane emission factors from active conventional wells were estimated at 138 g CH4 h−1. We did not find an emission pattern relating to age of wells or operator for active wells, however, the CH4 emission factor for active conventional wells was 7.5 times larger than the emission factor used by the EPA for conventional oil and gas wells. Our results suggest that well emission factors for active and abandoned wells can vary within the same geologic formation and may be affected by differences in state regulations. Therefore, accounting for state-level variations is critical for accuracy in greenhouse gas emissions inventories, which are used to guide emissions reduction strategies.
KW - Emission factor
KW - Methane
KW - Oil and gas wells
KW - State-level variation
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U2 - 10.1016/j.scitotenv.2018.10.082
DO - 10.1016/j.scitotenv.2018.10.082
M3 - Article
C2 - 30321717
AN - SCOPUS:85054962400
SN - 0048-9697
VL - 651
SP - 1849
EP - 1856
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -