Imaging of Geological Conditions Ahead of Drill Bit Using a Drilling Hole Dipole Source

To overcome shortcomings of current techniques in predicting geological conditions ahead of drill bit in real time, the capability of waves excited by a dipole source inside a fluid-filled drilling hole with surrounding and front formations in detecting geological reflectors is evaluated. Analysis on beam pattern show that SV and SH waves have large energy coverage and good reflection sensitivity, which have an advantage over P wave in detecting geological conditions ahead. Numerical results indicate that dipole acoustic sources have the capability of detecting geological conditions ahead of the drill bit.