Meshing strategies for 3d geo-electromagnetic modeling in the presence of metallic infrastructure

• In 3D geo-electromagnetic modeling, an adequate discretisation of the modeling domain is crucial to obtain accurate forwardresponses and reliable inversion results while reducing the computational cost. This paper investigates the mesh design forsubsurface models, including steel-cased wells, which is relevant for many exploration settings but still remains a numericallychallenging task. Applying a goal-oriented mesh refinement technique and subsequent calculations with the high-order edgefinite element method, simulations of 3D controlled-source electromagnetic models in the presence of metallic infrastructureare performed. Two test models are considered, each needing a distinct version of approximation methods to incorporatethe conductive steel casings of the included wells. The influence of mesh quality, goal-oriented meshing, and high-orderapproximations on problem sizes, computational cost, and accuracy of electromagnetic responses is investigated. The maininsights of our work are: (a) the applied numerical schemes can mitigate the computational burden of geo-electromagneticmodeling in the presence of steel artifacts; (b) investigating the processes driving the meshing of models with embeddedmetallic infrastructures can lead to adequate strategies to deal with the inversion of such electromagnetic data sets. Based onthemodeling results and analyses conducted, general recommendations formodeling strategies are proposed when performingsimulations for challenging steel infrastructure scenarios.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geofysik (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geophysics (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)