Tube-wave suppression in single-well seismic acquisition

Single-well seismic imaging is significantly hampered by the presence of borehole tube waves. A tube-wave suppressor has been tested using single-well seismic equipment at the Lost Hills (California) oil field. The suppressor uses a gas-filled bladder kept slightly above borehole fluid pressure. Field tests show a measurable reduction in tube-wave energy as compared to body waves propagating in the surrounding reservoir rock. When using a high-frequency (500-4000 Hz) piezoelectric source, the P-wave-tube-wave amplitude ratio was increased by 33 dB. When using a lower frequency (50-350 Hz) orbital vibrator source, the S-wave-tube-wave amplitude ratio was increased by 21 dB while the P-wave-tube-wave amplitude ratio was increased by 23 dB. These reductions in tube-wave amplitudes significantly improve single-well data quality.