The Study Of Inversion On The Seismic Data In HZ Region

This article is about the inversion study based on the actual datas of the HZregion of carbonate reef reservoir.The reef flat reservoir is inhomogeneous,heterogeneous and differential, then it is very difficult to predict them. The seismicinversion plays a more and more important role in the research work of delicateoil-gas exploration. The technology can actually reflect underground geologicalstructured and reservoir rock character, and can greatly raise the percentage of drillinghits. On the basis of fully consulting the research results of the reef flat reservoir, thethesis uses multiple methods of seismic inversion (including Recursive trace inversion,inversion based on models, Constrained spare pulses inversion, etc). The author took adetailed research on the basic principles, key technologies and applied conditions ofeach inversion method, and analysed advantages and disadvantages of each inversionmethod. Finally the author selected part of the sparse spike inversion as the finalmethod to inverse the target layer segment of the study area，and analyzed theresult.The several results and my understandings are follows:1) It is necessary to consider the various factors that affect the inversion, tocontrast and analyse of wavelets, the initial guess of the model and the inversionmethod of inversion results. The size of the errors between the seismic traces and notinvolved in the inversion of logging synthetic seismic traces are used to measure thepros and cons of the inversion effect.2) The author has made a comprehensive analysis of principles, applicableconditions and pros and cons of three inversion methods. Recursive trace inversionreflects the seismic data more faithfully, but its effect subjects to the initial seismicdata. It cannot meet the requests of thin reservoir description. Model based inversionmakes full use of seismic, logging and geology data, greatly improves the resolutionof 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 andfaith to seismic data. Because of the limit of assumptions, it cannot reflect slightvertical change of reservoirs.3) In the process of inversion, there are many parameters involved in variousinversion methods, such as hard constraint, soft constraint, the size of the block time,the number of iteration and etc. These parameters influence the effects of inversionstrongly. Each kind of parameters needs to carry on the multiple trials. Finally theoptimization parameters have been obtained suitably for this area.4)The core part of this article was about constrained sparse spike inversion onHZ area, and the inversion results were analyzed, and on this basis, the porosityprediction inversion was carried about.