Application Of AVO Fluid Recognition Technology Based On Spectral Decomposition In Halahatang Carbonate Reservoir

Carbonate hydrocarbon reservoirs in Hanilcatam are of high yield and great abundance,the researches and explorations have profound significance on development of petroleum industry in Tarim Basin.The Beadlike reflections are typical seismic characteristics of carbonate in this area,but Beadlike reflections can not distinguish whether the fluid is filled in the cave or not,let alone fluid component.At present,the method of focusing on beadlike reflections has not been able to meet exploration requirements in modern times.Therefore,it is urgent to establish a set of suitable fluid identification ideas and techniques for this area to improve reservoir prediction accuracy.In this thesis,study of karst reservoirs in Hanilcatam shows that when cave complexes are on a large scale,cave of containing different fluid will indicate different AVO characteristics.That is to say,when there is oil in cave reservoir,amplitude increases with the offset distance increasing;when there is water in cave reservoir,amplitude decreases with the offset distance increasing.Oil and water detection method based on spectral decomposition technique and AVO reflection characteristics is designed,considering the attenuation of high frequency components and the low frequency components of seismic wave in the course of actual propagation contain important information related to oil and gas.Based on theory of dispersion and AVO theory,this paper improve AVO dispersion gradient attribute inversion formula.Moreover,this paper combines spectral decomposition technique to make inversion of AVO dispersion gradient,for the sake of preserving the valid information related to fluid.Finally,this paper combines AVO fluid identification technology with AVO dispersion gradient attribute inversion for fluid detection,which not only effectively described the distribution of reservoir,but also make fluid identification come true.This study combined geology,drilling and seismic data,with a comprehensive application of spectral decomposition technique,AVO method and AVO dispersion gradient attribute inversion,summing a set of practically feasible comprehensive method to fluid identification for carbonate hydrocarbon reservoirs in Hanilcatam,providing a reference for the next well deployment and exploration and development.