Analysis And Application Of Uncertainty Surface Reconstruction Based On Fuzzy Set Theory

Geological surface reconstruction is an important technology in oil and gas exploration.It has a wide range of applications in geological modeling,structural mapping,reservoir modeling and so on.The basic idea of geological surface reconstruction is to use the structural data of seismic data to analyze the cross section and the level of the formation of the basic framework of the structure.In the process of seismic data acquisition,seismic data processing and seismic data interpretation,a number of uncertain factors are introduced,which leads to a large uncertainty in the data of structural interpretation.In essence,geological surface reconstruction is a problem of data inaccurate and information missing in the uncertainty of spatial surface reconstruction.In this thesis,based on the fuzzy characteristics of uncertain geological surface reconstruction,from the fuzzy set theory to carry out research,has a greater theoretical value and practical value.In this thesis,fuzzy reasoning and uncertainty are combined to solve the problem of uncertain geological surface reconstruction using the basic principle and method of fuzzy reasoning.The main work and innovation are as follows:1.An uncertain surface reconstruction method based on fuzzy reasoning is proposed.Aiming at the uncertainty of tectonic interpretation data,the concept of constructing data credibility is introduced in the process of geological surface reconstruction,and the problem is constructed into a fuzzy reasoning model based on credibility.On the basis of this,a method of reconstruction of uncertain geological surface based on two-dimensional fuzzy reasoning is proposed based on the correlation of geological surface space.After the simulation experiment,the two-dimensional algorithm not only conforms to the actual situation of the geological surface data,but also is more reliable than the one-dimensional algorithm in the fitting precision.2.A method of uncertain surface reconstruction based on nonlinear membership function is proposed.The traditional membership function uses a triangular function,which means that the membership degree is linearly proportional to the distance.We believe that the use of non-linear function to more accurately describe the degree of membership with the distance changes.Aiming at this problem,this thesis presents an uncertain geological surface reconstruction method based on nonlinear membership function.The basic idea is to use the Gaussian and bell-type nonlinear functions to describe the change of membership relation with distance,and to use the mathematical model of fuzzy reasoning to carry on the uncertainty geological surface reconstruction.Then the steepest descent method is used to optimize the variable parameters of the nonlinear membership function to form an adaptive reconstruction model.Through the simulation analysis,the geological surface reconstructed by nonlinear membership function is superior to the existing method.3.Design and implementation of fuzzy reasoning uncertain surface reconstruction system.Starting from the needs analysis,combined with the professional requirements of software users and the various functional requirements for software functions and module design.In the design of the software,do a good reliability,scalability,maintainability and security.In this thesis,we focus on the construction of uncertain geological surface reconstruction,and propose a method of reconstruction of uncertain geological surface based on fuzzy reasoning.At the same time,aiming at the shortcomings of traditional linear membership function,a fuzzy reasoning system based on nonlinear membership function is proposed and used in the reconstruction of uncertain geological surface.Through the simulation analysis,the method proposed in this thesis has achieved good results.