US 11,703,607 B2
Determining a seismic quality factor for subsurface formations from a seismic source to a first VSP downhole receiver
Simon Cordery, Dhahran (SA)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Jun. 15, 2020, as Appl. No. 16/901,914.
Prior Publication US 2021/0389489 A1, Dec. 16, 2021
Int. Cl. G01V 1/30 (2006.01); G01V 1/36 (2006.01)
CPC G01V 1/306 (2013.01) [G01V 1/368 (2013.01); G01V 2210/161 (2013.01); G01V 2210/677 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for determining a seismic quality factor Q for intervals of subsurface formations, the method comprising:
receiving vertical seismic profile traces;
filtering the vertical seismic profile traces with an inverse impulse response of a downhole receiver;
transforming the filtered vertical seismic profile traces from particle motion measured by the downhole receiver to far-field particle motion represented by a source wavelet;
determining a ratio of spectral amplitudes of a direct arrival event of the transformed vertical seismic profile traces and the source wavelet; and
generating, from the spectral ratio, a value for a quality factor Q representing an attenuation of the vertical seismic profile traces between a source at ground level surface and the downhole receiver;
generating, based on the value of the quality factor Q, a corrected seismic image, the corrected seismic image having a higher resolution than another seismic image generated independent from using the value of the quality factor Q; and
generating, based on the seismic image, a map of the subsurface formations.