US 12,147,004 B2
Method, apparatus, and system for identifying surface locations corresponding to subsurface geohazards based on frequency ratios among seismic trace signals
Yi Luo, Dhahran (SA); Tong Wang Fei, Dhahran (SA); Mohammed Mubarak, Safwa (SA); Ali Ameen Almomin, Dammam (SA); and Yi He, Beijing (CN)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Jan. 4, 2022, as Appl. No. 17/646,966.
Prior Publication US 2023/0213670 A1, Jul. 6, 2023
Int. Cl. G01V 1/30 (2006.01); G01V 1/36 (2006.01)
CPC G01V 1/301 (2013.01) [G01V 1/362 (2013.01); G01V 2210/1212 (2013.01); G01V 2210/21 (2013.01); G01V 2210/322 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of locating subsurface geohazards in a geographical area, comprising:
(1) receiving, by one or more processing apparatuses via a communication interface, a plurality of seismic trace signals generated by a corresponding plurality of receivers based on a shot gather from a seismic shot source, at least one of the seismic shot source and the corresponding plurality of receivers being located in the geographical area;
(2) picking, by the one or more processing apparatuses, a respective first break time of each of the plurality of seismic trace signals;
(3) shifting, by the one or more processing apparatuses, the each seismic trace signal based on its picked respective first break time to flatten the shot gather;
(4) stacking, by the one or more processing apparatuses, at least a subset of the plurality of seismic trace signals generated by at least a subset of the corresponding plurality of receivers within an offset range into a stacked trace signal;
(5) muting, by the one or more processing apparatuses, an output of the stacked trace signal after a predetermined time window to generate a windowed trace signal;
(6) applying, by the one or more processing apparatuses, a Fourier transform over time to the windowed trace signal;
(7) calculating, by the one or more processing apparatuses, a low frequency to high frequency ratio for the transformed trace signal;
(8) outputting, by the one or more processing apparatuses, the calculated ratio to a two-dimensional array representing the geographical area at a source location corresponding to the seismic shot source and at a mean receiver location corresponding to a mean location for the some or all of the corresponding plurality of receivers within the offset range;
(9) repeating, by the one or more processing apparatuses, steps (1) to (8) for a plurality of other shot gathers, wherein at least one of another seismic shot source and another corresponding plurality of receivers is located in the geographical area;
(10) multiplying, by the one or more processing apparatuses, each source location ratio with one or more mean receiver location ratios on the two-dimensional array to generate a final frequency ratio map;
(11) identifying, by the one or more processing apparatuses, one or more high risk surface zones on the final frequency ratio map based on a multiplied ratio threshold; and
(12) outputting, by the one or more processing apparatuses via the communication interface, the final frequency ratio map indicating the one or more identified high risk surface zones.