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The Research On Coherence Cube Technology With Self-adaptive Time Window

Posted on:2016-07-31Degree:MasterType:Thesis
Country:ChinaCandidate:Y Q LiFull Text:PDF
GTID:2180330467997414Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
Looking for oil and other mineral resources is a long-term strategic task in China.The main way of seismic mineral exploration is to interpret seismic data to master theunderground structure. It is important about how to detect and draw the fault in theseismic data interpretation. The coherence cube technology has become an importanttechnology for the interpretation of seismic attribute, which extracts thediscontinuities of the events through analyzing the similarities of adjacent seismicchannels to identify the fault form. At present, we have commonly made thediscussion about the coherence cube technology with fixed time window. However,the frequency band of seismic data varies with time. When using long time window,the algorithm will crossover a lot of events, which will lead to weak focusing abilityand failure to delineate the details. While using short time window, the algorithm cannot identify the complete form of wave, which will lead to low accuracy and weakinterference immunity. For solving the problem, we make a research on the coherencecube technology whose time window varies with frequency band.In this thesis, we make a research about how to detect and draw the fault, and putforward the coherence cube technology with adaptive time window based on WaveletTransform. Firstly, we make a discussion about coherence cube technology, especiallythe third coherence cube technology. Secondly, we make a research on how tocalculate the instantaneous attributes of seismic data, which will be used for adjustingthe length of time window. In the thesis, we calculate the instantaneous attributes byHilbert Transform and Wavelet Transform, which will be used for calculating the timewindow. Then we will discuss the result in the form of gray scale images. Due to thethree-dimensional characteristics of seismic data cube, we place the two-dimensionalresult into three-dimensional space for displaying the inner structure of coherencecube. Finally, we optimize the coherence cube method with adaptive time windowthrough the parallel method of OpenMP so as to reduce the running time of coherence algorithm.We improve the third coherence cube technology through Wavelet Transformtheory. We calculate the instantaneous seismic attributes to adjust the time window soas to improve the efficiency and precision of coherence calculation. At the same time,we make improvements to increase calculating speed with parallel strategy. The resultshows that we achieve great improvements on the precision of fault detection.And ithas excellent performance on the noisy seismic data. The thesis provides a new wayof improving the coherence seismic method, and it can assist the interpreters tointerpret the seismic data more efficiently.
Keywords/Search Tags:Seismic Data Interpretation, Coherence Cube Technology, Wavelet Transform, instantaneous attribute, self-adaptive time window, parallel strategy
PDF Full Text Request
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