The Research On Speed Modeling Method And Application Based On Image Segmentation Technology

Reasonable and accurate velocity model is an important part of seismic imaging process.Nowadays,many seismic data are obtained in areas characterized by complex buried hills or complex fault blocks.In order to estimate velocity correctly,horizon interpretation becomes particularly important.The essence of horizon interpretation is to interpret tectonic and stratigraphic geological units in seismic images.Nowadays,many interpreters use a rather complicated process to interpret,that is,first,to track the information on seismic profiles manually to locate the horizons and faults corresponding to the boundary of geological units.Then we glue these boundaries together to get a construction model.But this process consumes a lot of manpower cost and time cost,we can use seismic image segmentation to replace this process.Because the essence of horizon interpretation is equivalent to seismic image segmentation.Starting from image features,this paper studies several common segmentation methods and principles in the field of image segmentation and processing,and analyses their advantages and disadvantages as well as their applications.Then the image segmentation method is applied to seismic data image research.Firstly,seismic data is transformed into seismic gray level data,and then it is used as the data base of seismic image segmentation.Through various algorithms,a series of features such as energy,entropy,uniformity and contrast in seismic image are extracted by mathematical model or gray level co-occurrence matrix,or the characteristics of image boundary are characterized by the calculation of edge segmentation operator and threshold segmentation method.The most suitable parameters are selected after the effect analysis.On the basis of reasonable selection of feature parameters,the edge segmentation of seismic image is finally realized by processing the boundary features of seismic image,and the automatic or semi-automatic recognition of horizon and boundary information of seismic image is realized.The extracted boundary features are used to construct the horizon model.The horizon model is constrained by the horizon velocity model.Then the horizon constraints are added by regularization method to reduce the multi-solution of tomographic velocity inversion and calculate the velocity model.Finally,the velocity iteration inversion is carried out to update the velocity model.Or the extracted boundary features can be used as construction constraints to control the iteration of velocity in grid tomography velocity modeling.The velocity modeling of grid tomography under construction constraints can not only reduce the iteration time in inversion,but also make the velocity field more smooth and convergent,and establish a more perfect depth domain velocity model.The new model is compared with the old model.The evaluation criterion is whether the coaxial of CRP gather is flattened and the residual time difference converges to zero.The method is feasible.At the same time,a speed modeling system based on image segmentation technology is developed based on the QT platform,and a complete and extensible software development platform is formed.Finally,the existing problems and follow-up work are summarized and analyzed.