【作者】 王一重；

【导师】 刘财； 刘洋；

【作者基本信息】 吉林大学 ， 地球探测与信息技术， 2009， 硕士

【摘要】 在地震勘探资料解释中,探测和识别断层和断裂带是最重要的问题之一。识别断层的技术中,地震相干技术是最具代表性的。它是旨在计算由于构造、岩性、地层、空隙的变化及油气层等因素引起的地震响应横向变化的一种方法。在C1相干算法中,主要的影响因素有:搜索范围、时窗大小、不同道数的三角形组合模式。通过分析确定了搜索范围、时窗的大小和不同道数的三角形组合模式对低幅度构造的分辨率和追踪效果。C1相干算法通过波形的相似来对模型进行追踪,其不连续的位置为异常构造,但不能断定是否为断层构造。而小断层在地震剖面上表现出连续的地震反射发生错断或扭动,其波形的相似性发生变化,连续性变差。相干技术可以根据断层的这一地震反射特点,定量地算出在一定时窗内相邻地震道间的相干系数,就可以在相关值分布图上把细小断层反映出来。本文应用相干算法,计算其搜索范围为零相似系数(C(0))值,通过观察C(0)变化来识别断层构造。建立了二维水平断层、倾斜断层、三维水平断层、三维阶梯构造、三维盆岭构造、含有噪音阶梯构造等模型,应用相干算法对这些模型进行同相轴追踪;针对出现的异常构造求搜索范围τ=0时相似系数(C(0))值,观察其变化,来识别断层构造。并对结果进行分析,结果表明,应用上述方法可以识别效果较好。更多还原

【Abstract】 Fault identification and interpretation of research has a vital role in oil and gas fields in the process of exploration and development.Fault is a very important for oil and gas reservoirs,one of the geological features.Detection and identification of faults and fault zone is seismic data interpretation in one of the most important issues.in recent years,The interpretation of seismic data have become increasingly demanding when the development of oil and gas exploration work.Conventional seismic interpretation methods and traditional methods of seismic interpretation by a certain amount of constraint.Must seek a more accurate method of seismic data interpretation.With the seismic attributes the rapid development of technology and computer technology made the use of the wide,For example,Coherent.seismic technology is one of them.Coherent seismic technology is calculated changes in response to a method of horizontal for as the structure,lithology,stratigraphy,and changes in oil and gas gap layer and so on.Earthquake-induced changes in response to a method of horizontal is axis with the phase detection.In particular when the in-phase axis and the amplitude value of the smaller hidden in noiseC1 coherent selection algorithm in my article.The preparation of the procedures first of Algorithm for the coherent analysis of the parameters for algorithm.Analysis of search area:When the search area is too small, Coherence algorithm can reduce the computing time.But not suitable for large structures with seismic data.When the search area is too small,Structure is conducive to the identification of But the increase in computing time,the impact of efficiency.Therefore,the scope of the search to obtain an appropriate value. The value of the general search area T~*/2～3 T~*/2(T~* Wavelet as the cycle).Because this article is mainly for low-amplitude structures.Therefore,the value of search to T~*/4～T~*/2.Analysis of time window size:Access time window is too small can increase the resolution,is conducive to the identification of small faults,a clearer portrait of the details,but the impact on computational speed.But when there is noise,the small faults of other noise to cover up information,it is difficult to identify,only suitable for local area high-quality seismic data,if too much time window,the faster the more obvious big fault characterization,but easy to lose sight of the details of information,is not conducive to the identification of small faults.Range of time windows: T~*/2～3 T~*/2(T~* Wavelet as the cycle).A few different combinations of the triangle pattern analysis,The impact of noise in the absence of conditions.The use of C1 Coherence Algorithm.Combination of model space triangle 3 load triangle 5 load triangle 7 load of ladder model to track.The results showed that one of the three highest resolution.Clear not only to track a fault.To determine the location of faults than the 5 and 7 accuratelyCoherence parameters of analysis and discussion,Determine the parameters.The geological model was used of cl algorithm on different for tracking and identification.C1 coherent waveform similarity algorithm to track the model.Its not unusual for the location for the structure.But we can not determine whether the fault structure.Small faults show continuous seismic reflection or twist off the wrong took place in Seismic profiles.The similarity of the waveform changes.Coherence tomography technique can be characterized by the seismic reflection.Quantitatively calculated within a certain time window between adjacent coherent seismic coefficient.Value can be related to the distribution of small faults is reflected in.In my paper,coherence algorithm.Calculation of the scope of its search values zero coherence.By observing the C(0) changes to identify the fault structure.In this paper,Established a two-level faults,tilted fault,three-dimensional level of fault,three-dimensional ladder structure,three-dimensional basin and range structure,ladder structure to contain noise.Coherent application of these model algorithm phase axis tracking.Abnormal structure appeared for the scope of the search forτ=0 when coherence coefficient(C(0)) values.Observe the changes to identify the fault structure.The level of fault for the two-dimensional, three-dimensional level of fault,three-dimensional ladder structure,three-dimensional model of basin and range structure.Phase axis tracking.Calculation of the scope of its search whenτ=0 coherence coefficient(C(0)) values.Two-dimensional model of the level of fault.Coherence coefficient C(0) There are two numerical value and a point mutation Coherence coefficient C(0). Region in which the level of value formation,point mutations for the breakpoint. Two-dimensional tilted fault model,delay coherence coefficient(C(0)) is a uniform change,the two breakpoints in the Department,C(0) mutations,we indicate the location for the fault location.Discussed the different signal to noise ratio of the number of Triangle Road C1 coherent mix of the impact of algorithm.SNR when less than 1:0.2.Application of the three best.SNR when less than 1:0.4.3 and 5 poor results,7 the effect of general.Contain the noise level in the structural model. SNR when less than 1:0.2.Application of three triangles,to strike a coherent factor.Stratigraphic level of the coherence coefficient(C(0)) for the change in value,so coherent approximation factor.Coherence coefficient C(0) There are two numerical approximation,and a mutation at the level of approximation of regional stratigraphy,point mutation for the fault structure,so can it be said that the level of the structure for the fault structure,when less than 1:0.4.5 applications to strike a coherent triangle coefficient.Stratigraphic level of the coherence coefficient(C(0)) for the changes in the value of.Therefore,the approximation of coherent factor.Coherence coefficient C(0) There are three numerical approximation and two-point mutation.Approximation to the level of the regional stratigraphy,point mutation for the fault structure.So can it be said that the ladder structure for the fault structure.更多还原