Numerical simulation of electromagnetic LWD tool response in dipping anisotropic formation

Based on the method of coordinate transformation，the responses of electromagnetic logging-while-drilling（LWD) tool in dipping anisotropic formations are simulated and analyzed using the finite-difference time-domain（FDTD) scheme.The amplification strategy of dielectric constant is implemented to speed up the simulation in low frequency.The FDTD results are validated by comparing with the results of the paper by Hwa Ok Lee.The simulated results of LWD responses under different conditions show that the apparent resistivity mainly reflect the horizontal resistivity when formation dipping angle is lower than 30°； with higher dipping angle and frequency， the apparent resistivity is more affected by formation anisotropy；in addition， the phase-shift resistivity is more sensitive than the attenuation resistivity.