Controlled source electro-magnetic
The Controlled Source Electromagnetic (CSEM) method is an offshore geophysical technique,[1][2] employing electromagnetic remote-sensing technology to indicate the presence and extent of hydrocarbon below the seabed. But often noise perturbs the delineation and quantification.[3]
The CSEM survey uses a dipole source that is towed just above the seafloor to transmit a time-varying electromagnetic field into the earth. This field is modified by the presence of subsurface resistive layers and these changes are detected and logged by an array of receivers placed on the seabed. Because hydrocarbon-bearing formations are highly resistive compared with surrounding formations, a CSEM survey can indicate the presence of oil and gas in offshore situations.[4]
See also
- Exploration geophysics
- Electromagnetic Geoservices ASA
- WesternGeco
- List of oilfield service companies
References
- ^ Controlled Source Electromagnetic (CSEM) technique for detection and delineation of hydrocarbon reservoirs:
- ^ SIO Marine EM Laboratory
- ^ Bhatt, K. M. (2014), Microseisms and its impact on the marine‐controlled source electromagnetic signal, J. Geophys. Res. Solid Earth, 119, doi:10.1002/2014JB011024.
- ^ 2006 - mCSEM Marine Controlled Source Electromagnetic