A Monopole Dipole array Sonic tool for Openhole and Cased Wells


Lucio N. Tello, Edwin K. Roberts, Thomasj Blankinship, Computalog Research
Rick D. Kuzmiski, Computalog Ltd


A new wireline dipole acoustic device, the Monopole Dipole Array tool (MDA), has been developed for use in fast and slow formations in both openhole and cased wells (bonded and free pipe). The dipole acoustic source has a broad frequency bandwidth extending down to the 600 Hz range, low enough to excite large boreholes and very slow formations (>2000 }tsec/m). In addition, the unique, semi-rigid design, consisting of interlocking steel rings configured in a special pattern and individually isolated by an elastomer, enables this tool to be easily run in highly deviated boreholes.