Research On Fault Extraction Method Of 3D Seismic Signals

The fault attribute is a very important geological property.It is a fault structure in which the fault occurred in the rock formation.The fault plays a controlling role in the formation of oil and gas,forming an excellent reservoir in the trap.For the study of oil and gas resources,the fault is a part that can't be ignored.The precise description of the fault runs through the entire process of oil and gas field development.The development of subtle fault extraction and enhancement technology has become an urgent requirement for exploration.In this thesis,the importance of fault enhancement technology in today's new energy exploration is discussed.The development of fault enhancement technology and the research status at home and abroad are discussed.Then,the related principle of fault extraction technology are introduced such as denoising pretreatment,texture attribute extraction,fault enhancement technology and so on.In order to solve the problems existing in the prior technology,two kinds of fault enhancement methods are proposed from the aspects of fault characteristics,filter window shape and human visual characteristics.Specific work includes the following:1.Considering that the actual fault structure is usually expressed as a continuous plane,this thesis uses the three-dimensional derivative of stick(DoS)operator of the planar structure in the three-dimensional space to make it more suitable for the actual fault structure,while suppressing irrelevant noise.The results show that there are burrs,holes and bifurcations on the fault,and the morphological methods are introduced on the basis of the enhancement of the three-dimensional faults.The method designs the anisotropic filter operator according to the actual form of the fault and introduces the differential and morphological operation so that it can effectively preserve the obvious fault structure and enhance the small fault in the background.Remove irrelevant noise,can achieve the desired effect.2.Taking into account the use of the regular window used to enhance the fault usually contains too little useful information,this thesis puts forward the use of a curved window which is more consistent with the shape of the curve itself.First calculate the second moment tensor of each pixel in the coherent properties.The eigenvalues are decomposed to obtain the direction of the fault at each pixel,and the three-dimensional curve window is constructed from the fault direction.The Gabor filter similar to the human visual system is combined and extended to three dimensions to ensure the useful information while simplifying the filtering operation.The algorithm is applied to the actual work area for analysis.It can be observed that the effect of fault enhancement has been greatly improved,and the algorithm has achieved the expected effect.Finally,the above-mentioned fault enhancement method and the traditional method are applied on the three-dimensional seismic data volume of several real work areas.The results show that the practical effect of this method has certain advantages compared with the traditional one,and can achieve better fault enhancement effect.