Increasing the sensitivity of controlled-source electromagnetics with synthetic aperture

Increasing the sensitivity of controlled-source electromagnetics with synthetic aperture

Fan, Y.
Snieder, R.
Slob, E.C.
Hunziker, J.W.
Singer, J.
Sheiman, J.
Rosenquist, M.

Civil Engineering and Geosciences

Geoscience & Engineering

2012-02-23

Controlled-source electromagnetics (CSEM) has been used as a derisking tool in the hydrocarbon exploration industry. We apply the concept of synthetic aperture to the lowfrequency electromagnetic field in CSEM. Synthetic aperture sources have been used in radar imaging for many years. Using the synthetic aperture concept, big synthetic sources can be constructed by adding the response to small sources (building blocks) in different ways, and consequently, big sources with different radiation patterns can be created. We show that the detectability of hydrocarbons is significantly enhanced by applying synthetic aperture to CSEM data. More challenging targets such as deep reservoirs (4km belowsea floor) can be detected. The synthetic aperture technique also increases the sensitivity of the field to subsurface targets in the towing streamer acquisition.We also show that a pseudovertical source (orthogonally distributed dipole pairs) can be constructed synthetically, and that the detection capability of this pseudovertical source is increased by applying field steering. The synthetic aperture concept opens a new line of research in CSEM, with the freedom to design suitable synthetic aperture sources for a given purpose.

http://resolver.tudelft.nl/uuid:b98d9d7a-81b1-4524-a955-cb7b7fda5947

https://doi.org/10.1190/GEO2011-0102.1

Society of Exploration Geophysicists

0016-8033

Geophysics, 77 (2), 2012

Institutional Repository

journal article

(c) 2012 Society of Exploration Geophysicists