Abstract
AbstractIn 3D geo-electromagnetic modeling, an adequate discretisation of the modeling domain is crucial to obtain accurate forward responses and reliable inversion results while reducing the computational cost. This paper investigates the mesh design for subsurface models, including steel-cased wells, which is relevant for many exploration settings but still remains a numerically challenging task. Applying a goal-oriented mesh refinement technique and subsequent calculations with the high-order edge finite element method, simulations of 3D controlled-source electromagnetic models in the presence of metallic infrastructure are performed. Two test models are considered, each needing a distinct version of approximation methods to incorporate the conductive steel casings of the included wells. The influence of mesh quality, goal-oriented meshing, and high-order approximations on problem sizes, computational cost, and accuracy of electromagnetic responses is investigated. The main insights of our work are: (a) the applied numerical schemes can mitigate the computational burden of geo-electromagnetic modeling in the presence of steel artifacts; (b) investigating the processes driving the meshing of models with embedded metallic infrastructures can lead to adequate strategies to deal with the inversion of such electromagnetic data sets. Based on the modeling results and analyses conducted, general recommendations for modeling strategies are proposed when performing simulations for challenging steel infrastructure scenarios.
Funder
Ministerio de Ciencia e Innovación
H2020 Societal Challenges
Publisher
Springer Science and Business Media LLC
Subject
Computational Mathematics,Computational Theory and Mathematics,Computers in Earth Sciences,Computer Science Applications
Reference74 articles.
1. Newman, G., Alumbaugh, D.: Three-dimensional massively parallel electromagnetic inversion - I. Theory. Geophysical Journal International 128(2), 345–354 (1997)
2. Eidesmo, T., Ellingsrud, S., MacGregor, L., Constable, S., Sinha, M., Johansen, S., Kong, F., Westerdahl, H.: Sea bed logging (SBL), a new method for remote and direct identification of hydrocarbon filled layers in deepwater areas. First break 20(3), 144–152 (2002)
3. Avdeev, D.B.: Three-dimensional electromagnetic modelling and inversion from theory to application. Surveys in Geophysics 26(6), 767–799 (2005)
4. Constable, S.: Marine electromagnetic methods-A new tool for offshore exploration. The Leading Edge 25(4), 438–444 (2006)
5. Chen, J., Hoversten, G.M., Vasco, D., Rubin, Y., Hou, Z.: A Bayesian model for gas saturation estimation using marine seismic AVA and CSEM data. Geophysics 72(2), 85–95 (2007)