US 12,092,782 B2
Method and system for automatic picking of borehole acoustic events based on new objective function
Xuekai Sun, Beijing (CN); and Christopher Ayadiuno, Dhahran (SA)
Assigned to SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed on Jan. 20, 2021, as Appl. No. 17/153,314.
Prior Publication US 2022/0229202 A1, Jul. 21, 2022
Int. Cl. G01V 1/50 (2006.01); E21B 7/04 (2006.01)
CPC G01V 1/50 (2013.01) [E21B 7/04 (2013.01); G01V 2210/1299 (2013.01); G01V 2210/1429 (2013.01); G01V 2210/324 (2013.01); G01V 2210/6222 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for automatic picking of borehole acoustic events, the method comprising:
obtaining, by a computer processor, a plurality of sonic waveforms for each of a plurality of source and receiver positions along a borehole;
obtaining, by the computer processor, a sonic wave propagation velocity curve of a target event for the plurality of source and receiver positions along the borehole;
performing, by the computer processor, a linear moveout correction on the sonic waveforms based, at least in part, on the sonic wave propagation velocity of the target event for the plurality of source and receiver positions along the borehole;
stacking, by the computer processor, the linear moveout corrected sonic waveforms to generate a stacked waveform at the plurality of source and receiver positions along the borehole;
determining, by the computer processor, an arrival-time of the target event on the stacked waveform for each of the plurality of source and receiver positions along the borehole based, at least in part on an extremum of a first objective function based on the stacked waveforms,
wherein the first objective function includes first scalar weights selected by a user;
predicting, by the computer processor, a candidate arrival-time of the target event for the sonic waveform at the plurality of source and receiver positions based, at least in part, on the arrival-time of the target event on the stacked waveform for the plurality of positions, and the sonic wave propagation velocity of the target event for the plurality of source and receiver positions within the borehole;
determining, by the computer processor, an arrival-time for the target event on the sonic waveform at the plurality of source and receiver positions within the borehole based, at least in part on the candidate arrival-time of the target event and an extremum of a second objective function based on the sonic waveforms,
wherein the second objective function includes second scalar weights selected by the user;
determining, by the computer processor, a well path through a subterranean region of interest using the sonic waveform; and
drilling and logging the well path using a drilling system.