Calculation of Tube Wave Velocity in a Shallow Borehole Using Passive Seismic Recordings
F. Borges, D. Wehner and M. Landrø
Event name: 80th EAGE Conference and Exhibition 2018
Session: Poster: From Microseismic Data To Source Classification And Inversion
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 924.92Kb )
Price: € 20
With the initial goal of measuring the noise levels in our laboratory, we used an array of hydrophones to record around 11h of seismic data in a 95m-deep, water-filled well. No active seismic source was employed. During data processing, a coherent event was detected, and interpreted as a tube wave. The velocity of this event was calculated using two independent methods, with the results showing consistency with each other and over time. We believe this could be a way to continuously measure the tube wave velocities in wells, without the need of an active seismic source. Since the tube wave velocity is a function of the shear modulus of the formation behind the casing, this can be also used as a monitoring tool.