EM (Electromagnetic) Technology Enhances the Reservoir Model: The Concept of Seismic-to-Simulation Becomes Reality

Christophe Rimlinger

WesternGeco Electromagnetics Group (WGEM),
Kuala Lumpur, Malaysia

WesternGeco Electromagnetics Group (WGEM) conducted a CSEM (Controlled Source Electromagnetic) survey offshore West Africa. The objectives of this survey were to assess the sensitivity of CSEM measurements to resistive structures related to hydrocarbon accumulation; their resolving power given varying levels of constraints; and the inter-relationship between acquisition design, processing, and interpretation.

Using available seismic and well log data, pre-survey modeling was conducted to optimize survey acquisition parameters. The resulting survey design consisted of receivers on coarse grid spacing, multiple tow-lines, and a transmitter wave form with multiple fundamental frequencies designed to optimize sensitivity to the primary targets.

The data quality is generally excellent, yielding a data set rich in harmonic content and cross line coverage. The concept of Seismic-to-Simulation becomes reality with the EM technology enhancing the reservoir model. This paper presents the survey design methodology, operational challenges, enhancements of the reservoir model and results from the interpretation.