Seismic Abnormal Information Detection Based On The Adaptive Directional Diffusion Filtering

There is a lot of noise in the seismic exploration data,so filtering is the basis and key factor of seismic data processing.The spatial distribution of the fractured zones in the strata has a certain direction and ductility because of the action of the geological tectonic movement.Based on this property,we can suppress the background interference of seismic noise while selectively highlight the geological anomaly information in a particular direction,which is favorable to highlight the spatial distribution of the reservoir and the internal fine structure,fault and fracture systems,folds and other seismic anomalies information.A large number of studies have found that the wave field response characteristics of fault and fractured zones have obvious edge or boundary.Therefore,it is necessary to identify and delineate these boundaries to determine the spatial distribution of the fractured zones,and the identification of the fractured zones is transformed into search and detect the edge or singular value of the seismic wave field.In this paper,we study the adaptive directional diffusion filtering method,discussing the difference between the filtering method and the traditional filtering method.In the process of filtering,we can control the direction of filtering to highlight the abnormal information in the geological structure.Meanwhile,we discuss the two-dimensional curvature property and the three-dimensional volumetric curvature property.Listing the advantages and disadvantages of two-dimensional curvature through the comparative analysis two of them.The volumetric curvature property can make full use of the spatial orientation information of seismic data,and can reflect the relationship between the orientation of fracture and the regional stress,which contain more abundant geological information.The volume curvature property has a broad application prospect in the exploration,development and management of fractured reservoirs.The main contents of this paper include:(1)Adaptive directional diffusion filter analysis method.Adaptive directional diffusion filtering can be used for the selective recognition of the formation information.By controlling the filtering direction,the geological structure features can be better displayed,and the fine structure recognition effect can be achieved.In this paper,we introduce the principle of classical Gauss filter,and discuss the limitation of this method.Based on that,we derive the method of anisotropic Gauss iterative smoothing filter and its implementation.We set up the corresponding geological model to calculate,demonstrate the realization of the method,prove the feasibility of the algorithm,and highlight the superiority of the algorithm which compared with the classical algorithm.(2)Curvature attribute analysis and application in real seismic data.In mathematics,curvature is used to measure the degree of the bending curve,and the analysis of curvature is used for curvature attribute which is utilized to calculate the spatial distribution and describe the geometric changes of the geometric shape.Corresponding to the bending degree of seismic reflectors,curvature attribute is sensitive to bending,folding,cracks and faults,which is an effective means to find structural features of geological body.This paper introduces the calculation method of the layer curvature attribute,and analyzes the application and characteristics of the common curvature attribute.Then,we discuss the limitations of two-dimensional curvature.On the basis of the analysis of the instantaneous parameters,we deduce the method of 3D volumetric curvature attribute analysis.The results show that the 3D volumetric curvature is more accurate and comprehensive by comparing with the two-dimensional curvature.By utilizing the advantages of 3D volumetric curvature which can make full use of spatial orientation information,on the basis of the three-dimensional volumetric curvature attribute,we add the azimuth information to obtain the anisotropic volumetric curvature attribute analysis method.Analyzing the feasibility of the algorithm by processing the geological model and the actual seismic data.In order to further highlight the abnormal information of geological structure in seismic data,in this paper,we combine the adaptive directional diffusion filter with the anisotropic volumetric curvature property.The results of geological model and actual seismic data show that the method proposed in this paper can be used to suppress the background interference of seismic noise and to highlight the specific geological anomaly information.(3)Edge detection algorithm based on adaptive directional diffusion filtering.The adaptive directional diffusion filtering method can eliminate noise and makes the faults and cracks smooth and continuous in the geological structure.The algorithm can be used for edge detection of image and seismic data by improving it.In this paper,this method is applied to the edge detection of Lena model,comparing the edge detection results with the classical Prewitt operator,Robert operator and Sobel operator.The results show that the algorithm is better than the other three algorithms,whether it is in the outline or the details of the image,the result of the edge detection maintains a better continuity and rarely appears gap,burr and other shortcomings.In the application of the actual seismic data,this method has a good effect on the edge detection of the geological structure features such as faults,fractures,caves,and the ancient river channel,etc.