Efficient acquisition of electromagnetic data (EM)

Towed Streamer EM

Adding resistivity information to seismic can highlight prospective areas that may have been overlooked. The insight gained from the combination of seismic and 2D or high-density 3D EM data datasets has a range of valuable applications.

cost-effective regional and near-field exploration
reservoir level analysis of drilling hazards
hydrocarbon saturation and production optimization

Structural interpretation is supplied from the seismic data and resistivity values from the Towed Streamer EM system.

Example of a seismically guided inversion from the Barents Sea, Towed Streamer EM and GeoStreamer data

Technology

Processing and Inversion

Line spacing denser than 1.5 km can permit anisotropic inversion of 2D resistivity, one section per sail line, or a 3D resistivity volume. Projects with a line spacing greater than 1.5 km are considered 2D, with resistivity sections generated from 2.5D inversion.

Integration

Integrating seismic and EM data provides subsurface understanding that neither dataset enables alone. High-resolution resistivity models built from seismically-guided inversion can be used for quantitative interpretation of EM data. Anisotropic 2.5D and 3D inversion significantly improve lateral and vertical resolution of anomalies.

Benefits of Adding Towed Streamer EM Data

Adding EM data to seismic increases exploration success. Integrating data from both technologies aids analysis and improves understanding, to help asset teams improve their ranking of prospects and reduce drilling risk.