Approximations of Steel Cased wells for a DC resistivity experiment

In this example, we examine the impact of upscaling the well using- the assumption that the well is a solid rod of steel- averaging conductivity such that the product of the electrical conductivity and cross sectional area is the same in both cases<br>These experiments are conducted at DC. The initial model we consider is based on that shown Um, 2015: Finite element modelling of transient electromagnetic fields near steel-cased wells (https://doi.org/10.1093/gji/ggv193)<br>For the full write-up, please see the notebook Approximating_Steel_Cased_Wells_DC.ipynb<br><b>Reproducing these results</b>To run these examples, please see requirements.txt for the required packages (`pip install -r requirements.txt`). If you run into issues, please make an issue on github: https://github.com/lheagy/casingNotebooks/issues/new <br>SimPEG and the implementation for electrical and electromagnetic methods is described in (Cockett et al., 2015: https://doi.org/10.1016/j.cageo.2015.09.015 and Heagy et al., 2017: https://arxiv.org/abs/1610.00804)