Massachusetts Institute of Technology. Earth Resources Laboratory
Abstract
Recent logging tools have monopole and dipole sources in one system, and the monopole and dipole components are
acquired by adding or subtracting responses at four monopole (pressure) receiver arrays at right angles. We investigate the effects of
tool eccentricity on this monopole receiver array system for three different eccentricity directions. To simulate responses at each
receiver array, we use the discrete wavenumber method. An off-centered dipole source produces nondipole modes as well as the
dipole mode and the responses detected at each receiver array have different features as eccentricity direction varies, showing the
similar pattern for both fast and slow formation. We separate the modes included in a response and compare the amplitude of each
mode to the other modes. By considering responses at each array separately, we can precisely resolve the effects associated with
eccentricity direction.Massachusetts Institute of Technology. Earth Resources LaboratoryMassachusetts Institute of Technology. Borehole Acoustics and Logging Consortiu
