Reservoir fracture prediction based on OVT domain HTI medium attenuation anisotropy and its application
Quality factor Q is an important parameter to characterize seismic wave attenuation,which is widely used in reservoir fracture development characteristics and oil & gas bearing identification.However,under the constraints of different media models such as isotropic,anisotropic,and viscoelastic models,the obtained Q va-lues have different reservoir characterization capabilities.To accurately describe the anisotropy and fracture de-velopment characteristics of fracture type,fracture-porosity and porosity-fracture reservoirs,we propose a new method for reservoir fracture prediction based on the HTI medium medium model and seismic wave attenuation anisotropy theory in the OVT(offset vector tile)domain.Firstly,we use generalized S-transform(GST)to perform high-precision time-frequency analysis of OVT pre-stack gather.Then,we calculate the single fre-quency T-K energy of seismic wave by Teager-Kaiser energy operator.After that,we calculate the relative at-tenuation within the sampling wavelength distance to obtain the attenuation Q-value for ellipse fitting.Besides,we utilize ellipse oblateness to characterize attenuation anisotropy strength and to predict fracture development density.This method not only gives full play to the advantage that OVT pre-stack gather contains more reser-voir fluid and fracture information than post-stack data,but also links attenuation attributes with reservoir frac-ture characterization,providing a new approach for fracture prediction.In the application of XC gas field in Western Sichuan Depression,the method has achieved the fracture identification effect with high consistency be-tween core analysis,logging interpretation and seismic prediction.
reservoir fracture predictionattenuation anisotropyquality factorHTI mediumOVT seismic data
万方数据
维普
