Resolution analysis of several types of dipole source detecting seabed thin layer of high resistivity in marine controllable source electromagnetic method

Aiming at several typical dipole source emission devices in marine controlled-source method, a high resistivity reservoir model of anisotropic formation is established, and a one-dimensional stratigraphic analysis method based on Green function is adopted. With the reciprocal nature of the electromagnetic field, the electromagnetic response generated by different dipole sources are calculated. The electromagnetic response characteristics of different dipole sources are analyzed, and the amplitude and phase normalization curves of each electromagnetic field are compared. The results show that the amplitude normalization curve of the vertical electric dipole source has the greatest response to the anomaly, and the resolution of the high resistive layer is higher than that of the vertical magnetic dipole source. The axial observation mode of the horizontal galvanic source and the equatorial observation mode of the horizontal magnetic dipole source have good resolution. In this two modes, the measured electric field parallel to the survey line and the magnetic field perpendicular to the survey line have the best resolution, and there is an optimal transmitter-receiver distance, and the phase also has the same variation.