Research on azimuthal electromagnetic tool while drilling measuring method of compensation

Key words:  transverse antenna  azimuthal electromagnetic  compensation measurement  anisotropy  geosteering

Abstract:

Based on analytical solutions of the electromagnetic field in layered anisotropic formations, the fast responses of azimuthal electromagnetic tools with transverse antenna were simulated. Taking azimuthal multiple resistivity (AMR) tool of Shengli Drilling Technology Research Institute and azimuthal propagation resistivity (APR) tool of Baker Hughes as examples, the responses of different axial transmitter (T) and transverse receiver(R) couplings, such as single T-R,T-R-R, T-R-T,T-R-R-T, were numerically simulated, and were used to analyze the effects of compensation measurements. The simulation results show that the single axial transmitter and transverse receiver coupling can simulate the basic function of the azimuthal electromagnetic measurement, but the measured results can be biased by the surrounding formation conditions, which limits the use of the azimuthal electromagnetic measurements. The transmitter or receiver compensation can correct the influence from tool eccentricity, relative angle deviation and resistivity anisotropy to make the better use of the azimuthal electromagnetic measurements in geosteering.