Patent ID: 9714566
Date: 2017-07-25
CPC Classifications: E21B,G01V

Claim:
1. A method of determining a location of an acoustic source outside of a borehole, the method comprising: receiving acoustic data signals from respective acoustic sensors spaced along a tool lowered within the borehole; calculating, from the acoustic data signals, stacked energies for different radial distances from the borehole, wherein the stacked energy for each different radial distance from the borehole is computed by offsetting the acoustic data signals in time in accordance with a borehole model specifying acoustic delay to the respective acoustic sensor as a function of the radial distance from the borehole and an offset in the displacement along the borehole to the respective acoustic sensor, and summing the offset acoustic data signals to produce a stacked signal, and evaluating energy of the stacked signal over a time window; and translating at least one of the stacked energies to an indication of a radial distance of the acoustic source from the borehole.