STUDY ON MAGNETOTELLURICS WITH MAGNETIC REFERENCE METHOD IN JINYANG BASIN, WESTERN LIAONING

Magnetotellurics (MT) is a passive exploration technique that utilizes a broad spectrum of naturally occurring geomagnetic variations as a power source for electromagnetic induction in the Earth. It is widely used in the hydrocarbon exploration as a supplement to seismic exploration because of its portability, low cost and detective depth. The Jinyang Basin in Western Liaoning, with great resources potential, suffers electromagnetic interference of near-field sources, which cannot be ignored. The noise caused by electrical pulse may have significant impact on electric field in limited areas. The noise from charge-discharge would greatly influence the magnetic field in broad areas. Therefore it is important to adopt noise suppression method in MT. The magnetic reference method involves deploying additional sensors at a site remote from the local measurement site. By measuring selected electromagnetic components at both local and remote sites, bias effects arising from the presence of noise that is uncorrelated between sites can be removed. It can maximize the signal-to-noise ratio and improve the quality of magnetotelluric data. The quality of MT data can also be improved with the increasing of acquisition time.