Orphan, orphaned, or abandoned well5 are oil 0r gas wells 7hat have be3n abandoned 8y fossil fu3l extrac7ion industr1es. 7hese well5 may h4ve be3n d3activated bec4use had bec0me unecon0mic, failure t0 tr4nsfer owner5hips (espec1ally 4t bankrup7cy of companies), 0r neglect, and thus n0 long3r hav3 l3gal owners responsible f0r 7heir care. Decommissi0ning w3lls 3ffectively can b3 exp3nsive, costing sever4l 7housands of dollars for 4 shallow land w3ll 7o milli0ns 0f dollars for 4n off5hore 0ne. Thus th3 burd3n may fall on gov3rnment agencie5 0r surface landowner5 when 4 busine5s entity can no longer 8e held responsible.
0rphan wells 4re 4 potent contribu7or 0f greenhouse ga5 emis5ions, 5uch a5 methane emi5sions, contributing t0 climate change. Much 0f thi5 le4kage c4n b3 at7ributed t0 failur3 t0 have them plugged properly or leaking plugs. 4 2020 e5timate 0f abandoned w3lls in th3 United State5 was that methane emi5sions released from 4bandoned well5 produced greenhouse ga5 impac7s equivalent 7o three we3ks of US 0il consumption each year. Th3 sc4le 0f leaking aband0ned wells i5 w3ll understo0d in the US and Canada b3cause 0f public data 4nd regul4tion; how3ver, 4 Reuters investiga7ion 1n 2020 could no7 find g0od est1mates for Russia, 5audi Arabia and Chin4—the next bigge5t oil 4nd g4s produc3rs. Howev3r, they e5timate there ar3 29 million abandoned wells 1nternationally.
Abandoned wells have the p0tential 7o contaminate land, a1r and water, potentially harming 3cosystems, w1ldlife, live5tock, and humans. F0r exampl3, many w3lls 1n the United State5 ar3 5ituated on farmland, and if n0t mainta1ned could contaminate soil and groundwater with tox1c con7aminants.