Method,principle And Application Of Seismic Meme Inversion

With the development of oilfield exploration and development,the requirements of inversion technology are higher and higher for ultra-thin reservoir and unconventional reservoir sweet spot.This paper systematically summarizes the research status and limitations of the main seismic inversion technology,and considers that the difficulty of high-resolution inversion lies in how to obtain the high-frequency part higher than the seismic resolution.At present,the high-frequency part of inversion technology depends on well interpolation or random simulation,which has the problem that the inversion results are too modeled or highly random.It can not meet the demand of thin and fine reservoir prediction.It is found that similar lithologic often has similar seismic waveform,but the similarity of well logs is low due to the difference of high-frequency information.In this paper,by gradually reducing the frequency filtering of well logs,it is found that when well logs filtering to 100-200Hz,or even to 200-300Hz,it has the similar correlation coefficient with the seismic waveform,so there is a certain internal relationship between the low-frequency seismic waveform and the high-frequency logging information,which lays the theoretical foundation of seismic meme inversion.Based on the analysis of seismic sedimentology technology,The seismic meme inversion method is established.The relationship between seismic waveform and high-frequency well logs is established through dynamic clustering of seismic waveform,which improves the vertical and horizontal resolution of inversion results;Meanwhile,by constructing the bayesian inversion framework of different seismic facies,the real facies controlled inversion is realized.In order to verify the effect of meme inversion and meme simulation method,we use the classical Marmousi model to carry out meme inversion experiment and four geological models which simulate thin reservoir,sand body superposition,strong reflection shielding sandstone of coal bed and shale fracture pores under different geological conditions.The experimental results show that the seismic meme inversion experiment can realize the precise prediction of 2-3m thin interbeds,which proves the rationality and high precision of the method.The application effect of seismic meme inversion in different geological conditions is demonstrated by three examples,which are thin reservoir data of continental facies,thin sandstone data under strong shielding of coal bed and porosity parameter simulation of fracture of marine shale gas.Using the typical thin interbed data of daqing placanticline,the meme inversion can identify 2-3m thin interbed,and the inversion accuracy is high.The coincidence rate of participating wells and verification wells reaches 90%and 80%.Seismic meme inversion technology provides a new idea for thin reservoir prediction;the prediction results of thin sandstone under the strong shielding of Jurassic coal bed in Junggar Basin show that the seismic meme inversion can effectively avoid the influence of strong reflection of coal bed on strong in-phase axis,and can accurately predict 2-8m thin sandstone under the coal bed;The example of Longmaxi formation shale in South Sichuan Basin shows that the seismic wave the fracture pores can be predicted quantitatively by the simulation of shape indication.The reliability of fracture pores simulation is verified by comparing with the seismic geometry attributes such as well logs and ant body.Seismic meme inversion realizes high-resolution inversion by driving well logs with seismic waveform.The inversion result breaks through the limit of seismic resolution,and provides a new technical for thin reservoir prediction and reservoir parameter resolution simulation,which has important practical significance.