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Evaluation Of Impedance Inversion On The Carbonate Reef Flat Reservoir

Posted on:2012-12-15Degree:MasterType:Thesis
Country:ChinaCandidate:F L LeiFull Text:PDF
GTID:2210330338968091Subject:Applied Geophysics
Abstract/Summary:PDF Full Text Request
The reef flat reservoir was inhomogeneous, heterogeneous and differential, then it is very difficult to predict them. The seismic inversion plays a more and more important role in the research work of delicate oil-gas exploration. The technology can actually reflect underground geological structured and reservoir rock character, and can greatly raise the percentage of drilling hits. On the basis of fully consulting the study result of the reef flat reservoir, the thesis uses multiple methods of seismic inversion (including Recursive trace inversion, Model based inversion, Constrained spare spike inversion, etc). The author takes a detailed research on the basic principles, key technology and applied condition of every inversion methods, analyses advantages and disadvantages of each inversion method and applied effectiveness. The several results and my understanding are follows:1) It had been done a systematic understanding on the geological characteristics in the research area, such as the basic principles, main classification and sedimentary environment of the reef flat reservoir. The author has summarized geophysical response characteristics.2) Wavelet affects the effects of horizon calibration and finally results of the inversion. The author analyzed the length of wavelet, time windows, take-off time and other factors, continued to carry out horizon calibration and error analysis, estimate the optimal wavelet. And the error of the final inversion results is the smallest.3) The author has made a comprehensive analysis of principles, applicable conditions and pros and cons of three inversion methods. Recursive trace inversion reflects the seismic data more faithfully, but its effect subjects to the initial seismic data. It cannot meet the requests of thin reservoir description. Model based inversion makes full use of seismic, logging and geology data, greatly improves the resolution of inversion results, better able to reflect lithological characters and physical properties of reservoir. However, it has the relatively large impact of the initial model. Constrained spare spike inversion is able to reflect the lateral change of reservoirs and faith to seismic data. Because of the limit of assumptions, it cannot reflect slight vertical change of reservoirs.4) The inversion of a research based on STRATA of the inversion soft. In the soft there are a great many parameters in the course of model based inversion, such as hard constraint, soft constraint, the block time, the number of iteration and etc. These parameters influence the effects of inversion. Each kind of parameters needs to carry on the multiple trials. Finally the optimization parameters have been obtained for this area.5) Evaluation of impedance inversion. First of all, Based on logging data and geology data of the researched area, analyzing vertical and horizontal resolution and the coincidence with the logging data, the author has chosen the inversion method suitable for the area. Then, the geological interpretation about inversion results of this method has made.
Keywords/Search Tags:Recursive trace inversion, Model based inversion, Constrained spare spike inversion, Wavelet estimation, reef flat reservoir, Inversion parameters
PDF Full Text Request
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