Research And Application Of Thin Reservoir Inversion Method Based On Multi-scale Inversion

Many reservoirs in China are thin layers.Today's inversion method does not make full use of seismic data relative to low and high frequency information.The resolution can't identify thin layer.In order to improve the accuracy of horizon calibration,establish high precision initial model and reduce the multi-solution of inversion,this paper proposes three new methods: Multi-band matching calibration,Direction-distance modeling method,and Multi-scale inversion.Multi-band matching calibration provides accurate time depth relation for Multi-scale inversion.Direction-distance modeling method provides a high precision initial model for Multi-scale inversion.Through the application of actual material in Andes working area,the following three understandings are formed:(1)Horizon calibration is a bridge to establish the relationship between wells and seismic data.Using median filtering and square wave to preprocess the well data can suppress the noise and obtain the reflection coefficient sequence,which has sparse characteristics.Seismic data from different frequency bands reflect different geological information.Multi-band matching small layer calibration can obtain good calibration effect at the same time in low,medium and high frequency bands.(2)The Direction-distance Model can avoid "bovine-eye phenomenon" caused by Inverse Distance Weighting Method.(3)The Multi-scale Inversion is based on the position of the time-frequency graph "Frequency branch" to set the frequency band range.Initial model and seismic data are decomposed into large,medium and small scale data.The inversion results of each scale are added according to a certain weight,and the final inversion results are obtained.Multi-scale inversion can produce higher resolution than the conventional inversion,and can identify the layers thinner than 10 m.Finally,on the basis of method research,software is successfully developed by using C++ programming language and Qt interface design framework.Three software modules that can run independently,namely,multi-band matching calibration,Direction-distance modeling and Multi-scale inversion.