Fractured reservoir characterization using VSP and surface data: a case study from the Paris basin. (2nd May 2018) - Li, Hanqing
Abstract: Anisotropic characteristics are mainly attributed to fractures in fractured reservoirs. The Dogger formation in the Paris basin is a kind of fractured carbonate reservoir, and the nine-component surface seismic and vertical seismic profiling (VSP) data were acquisited in this area. To characterize the fracture attributes, we analyzed the differential variation of each attribute of the vector wavefield, such as velocity ratio, polarizations, amplitudes and differential travel times. The results described using these parameters had a good match with the overall shear wave anisotropy in the Dogger formation. Two VSP data verified our results. There was about four percent anisotropy in the horizontal direction, which could be interpreted as the porosity and permeability changing along the Dogger layer. The differential shear-wave amplitude from the top of the Dogger shows an overall dimming. There were about six intervals in the shear wave section, which showed that shear wave processes and interpretation provided more information than the P-wave section. The interpretation with shear wave anisotropy showed advantages in revealing detailed lateral variations in fractured reservoirs.