Efficient 3D Finite Element CSEM Modeling with Unstructured Tetrahedral Meshes Using a Parallel Direct Solver
A.R. Sena, D.X. Colombo, E. Sandoval Curiel, E.S. Um and J. Harris
Event name: 76th EAGE Conference and Exhibition 2014
Session: Seismic Modelling II
Publication date: 16 June 2014
Info: Extended abstract, PDF ( 1.68Mb )
Price: € 20
We developed an efficient 3D Finite Element (FE) Controlled Source Electromagnetic (CSEM) simulator in the frequency domain with unstructured tetrahedral meshes using a parallel multithreading direct solver. The new simulator is based on edge finite element and solves the diffusive electric field equation. It shows a speed up of more than an order of magnitude relative to a previous serial version and can solve problems with millions of tetrahedral elements. The simulator is also capable of injecting general distributed current sources to be used for adjoin-field based inversion. The code is benchmarked against a semi-analytical technique using layered media and is demonstrated using a realistic reservoir saturation model obtained with a black oil simulator. The results show that simulations of realistic models with ~ 3 million tetrahedral elements can be handled effectively in a single node using current “off the shelf” computing components (in this case, 4 processors x 4 cores each, and 128 GB of shared RAM memory).