Fracture Prediction Based On Curvature Geometry Attribute Of Seismic Data

For the study of fractured reservoirs,the most important and difficult problem is to accurately predict the development degree and distribution range of fractures.The distribution of the fracture is extremely complex,The curvature attribute based on seismic data can accurately reflect and predict the development rules of fractures,and the curvature attributes can effectively improve the precision and accuracy of the fracture prediction.The main characteristics of Nanpu depression is faults and fractures are very developed,which play a very important role in storage and migration of hydrocarbon reservoir in Nanpu,so far,the middle and shallow layer of Nanpu still has great resource potentiality and exploration prospect.Therefore,in this paper,the faults and fractures development of the Nanpu are predicted by curvature attributes extract from seismic data volume.the main results are as follows:(1)Two calculation methods of curvature attributes are proposed,one is the surface curvature,The curvature values are obtained by fitting the trend surface based on the 3x3 grid;the other is the three-dimensional volumetric curvature attribute,which comprehensive use spatial orientation information of seismic data volume.the algorithm of discrete derivative is used to obtain the volumetric curvature by first-order derivative of seismic events inclination data.At the same time,Compared the effect of fractures identification by curvature attributes.(2)Three kinds of preprocessing methods of seismic data were defined,and the conditions and effects of each method are compared and analyzed.the basic principles and characteristics of three seismic data preprocessing methods,median filter,Gaussian filter and Structure oriented filtering are discussed and analyzed,and discussed the filter window size and the number of iterations of the filter effect,compared to the different filtering of seismic data noise suppression effect,so that the most appropriate filtering method for seismic data preprocessing.(3)The fracture prediction of the No.2nd structure in Nanpu depression has been made by using the level curvature attribute and the body curvature attribute.The curvature of the plane is mainly used to calculate the curvature value of the layer calculated by the seismic data body and to predict the development zone of the fracture.The fracture prediction of the body curvature attribute is firstly based on acquiring the curvature property,tracking the faults in the study area and establishing the fracture distribution of the whole region.Then the curvature attribute and the ant-tracking technique are combined to obtain the fracture distribution in the region,and the fracture fragments are extracted,and the discrete model of fracture is established by using the method of deterministic modeling to obtain the geometrical features of the crack's trend? inclination and length.