Simulating multi-component low-frequency MCSEM responses in anisotropic formation using weak-form BCGS algorithm for volume integral equations

Key words:  volume integral equations  MCSEM (marine controlled-source electromagnetic)  anisotropy  multi-component

Abstract:

The multi-component low-frequency marine controlled-source electromagnetic(MCSEM) responses in anisotropic background formation were simulated based on dyadic Green 's functions for stratified uniaxial anisotropic medium and weak-form BCGS algorithm for volume integral equations. The influence of the transmitter frequency, anisotropy in the submarine background formation and the depth of the abnormal body were analyzed by numerical models. The results show that different frequencies of the transmitter and different components of the electric field have different horizontal resolutions for detecting the submarine oil reservoir. When the survey line is disposed alone x-direction, the resolving ability of the E_zz-component is most powerful, the E_xx-component comes second, and the E_yy -component has lowest resolution ability. On the condition of the same horizontal conductivity of the submarine background formation, changes in the vertical conductivity of the background formation have different influences on E_xx-component and E_zz-component, while the E_yy-component keeps unchanged. The horizontal resolving ability of E_xx-component and E_zz-component become higher when the depth of the abnormal body becomes shallower, while the E_yy-component cannot resolve the abnormal body no matter whether the depth is shallow or deep.