A Numerical 1.5D Method for the Rapid Simulation of Geophysical Resistivity Measurements

In some geological formations, borehole resistivity measurements can be simulated using a sequence of 1D models. By considering a 1D layered media, we can reduce the dimensionality of the problem from 3D to 1.5D via a Hankel transform. The resulting formulation is often solved via a semi-analytic me...

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Detalles Bibliográficos
Autores: Shahriari, M., Rojas, S., Pardo, D., Rodríguez-Rozas, A., Bakr, S.A., Calo, V.M., Muga, I.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Basque Center for Applied Mathematics (BCAM)
Repositorio:BIRD. BCAM's Institutional Repository Data
OAI Identifier:oai:bird.bcamath.org:20.500.11824/854
Acceso en línea:http://hdl.handle.net/20.500.11824/854
Access Level:acceso abierto
Palabra clave:logging-while-drilling (LWD)
resistivity measurements
finite element method
Hankel transform
multi-scale method
secondary field
Descripción
Sumario:In some geological formations, borehole resistivity measurements can be simulated using a sequence of 1D models. By considering a 1D layered media, we can reduce the dimensionality of the problem from 3D to 1.5D via a Hankel transform. The resulting formulation is often solved via a semi-analytic method, mainly due to its high performance. However, semi-analytic methods have important limitations such as, for example, their inability to model piecewise linear variations on the resistivity. Herein, we develop a multi-scale finite element method (FEM) to solve the secondary field formulation. This numerical scheme overcomes the limitations of semi-analytic methods while still delivering high performance. We illustrate the performance of the method with numerical synthetic examples based on two symmetric logging-while-drilling (LWD) induction devices operating at 2 MHz and 500 KHz, respectively.