Application of OVT domain combined imaging technology of offshore two-azimuth seismic data in fault shadow areas
The fault-controlled reservoirs are important targets of exploration and development.Structural imaging distortion is commonly present in seismic shadow areas caused by faults,and the conventional offshore narrow azimuth three-dimensional(3D)seismic data is difficult to satisfy the structural research under this back-ground.According to two-azimuth seismic streamer acquisition data in different years of typical fault-controlled reservoirs in the South China Sea,this paper analyzed the difference of 3D seismic data in different azimuths by velocity investigation.Based on the fused seismic gather data processed by prestack consistency and five-dimen-sional(5D)regularization,fault-controlled constrained grid tomography velocity modeling and tilted trans-versely isotropic(TTI)medium depth migration in the offset vector tile(OVT)domain were adopted,and high precision anisotropic velocity model was obtained.The actual seismic data processing results show that the data quality of the two-azimuth fusion in the depth domain is significantly improved,and the fault surface imaging accuracy is high.The seismic reflection energy is focused in the fault shadow areas,and the events are continuous.The structural distortion is basically eliminated,and the depth error with newly drilled well is greatly reduced.It provides a reliable basis for structural research and efficient oilfield development and offers a new idea for exploration of the same type of fault-controlled reservoirs in the region.
国家科技期刊平台
NSTL
万方数据
