The Application of Full Waveform Inversion Velocity Modeling Technology in Structural Distortion Area of Liuhua Deepwater Oilfield

GUO Li; WU Yiming; LI Li; GUO Fei; DONG Zheng; LIU Nan

doi:10.13512/j.hndz.2026.01.14

Abstract：The Liuhua deep-water oilfield is characterized by a tilted semi-anticline structure,with the main con-trolling faultexhibiting significant throw(approximately 300 m)and the substantial velocity variations across its two walls.Conventional velocity modeling techniques often fail to accurately capture the sharp velocity contrasts across the fault,leading to structural distortion within the fault shadow zone of the reservoir.Full waveform inversion(FWI),which comprehensively utilizes kinematic and dynamic information of the seismic wavefield,can recover higher frequency velocity components compared to conventional methods,offering distinct advantages for accurate imaging of complex structures.Therefore,high-precision FWI velocity modeling has been applied for the first time in the Liuhua deep water area.To address the geological and acquisitionchallenges in the study area,this study adopts a structural constraints,time-domain multi-scale FWI approach.First,a low-wavenumber velocity back-ground was established through velocity analysis and traveltime tomography.Subsequently,Gaussian beam tomog-raphy was employed to derive a high-precision,medium-wavenumber velocity field as the initial model for FWI pro-cess from low to high frequencies,structural trends were incorporated as constrains to mitigate cycle-skipping is-sues.Finally,a high wavenumber FWI velocity model was successfully constructed.The application of this method accurately delineates the velocity contrast across the fault walls and effictively corrects the"pull-up"distortion within the fault shadow zone.Post-test applysis demonstrates that structural errors have been reduced from 25 m to less than 5 m,improving structural interpretation accuracy by approximately 10%.This technique has effectively guided development adjustment and potential exploitation in the Liuhua deep-water oilfield and holdspromising val-ue for application in similar fields.