Electrical and electromagnetic responses over steel-cased wells

Electrical and electromagnetic (EM) methods can be diagnostic geophysical imaging tools for monitoring applications, such as carbon capture and storage or hydraulic fracturing. In these settings, it is common that steel-cased wells and other steel infrastructure are present. In this paper, we revisit and examine some of the fundamental physics of grounded-source electrical and EM surveys in settings with steel-cased wells. We highlight examples where steel casing can help targets at depth be detected and illustrate how EM methods can improve detectability. We also discuss some of the challenges that require further research for us to work with these data in practice, including numerical modelling and the implications of magnetic permeability.