近地表吸收补偿及其在AVO分析中的应用

发布时间：2018-09-19 18:53

【摘要】：近地表低降速带给高精度地震勘探带来了很多不利的影响。相对深层致密的地层来说,疏松的近地表低降速带对地震高频信号的吸收衰减十分严重,致使近地表岩性空间发生变化,激发能量和激发子波也随之产生严重的空间变化,引起最终成像及储层反射地震属性信息的变化,这种变化要远大于地质和油气因素引起的储层信息变化。品质因子Q本身反映了地层岩石的物理特性,为了消除地震波在近地表介质传播过程中的频散吸收,提高地震资料的分辨率,采用反Q滤波对地震波进行补偿是一种有效的方法。本文首先介绍了影响地震波在近地表传播过程中的因素及反Q滤波方法,分析了吸收衰减的物理机制及特性,建立了表层吸收衰减理论模型；接下来,采用吸收补偿技术对Q值进行定量估算,得到了Q值建场思路与方法。通过对近地表衰减量的测量,找到衰减规律,得到了近地表吸收补偿方法并在此基础上来补偿近地表的吸收衰减；最后,通过AVO属性分析,建立AVO处理模型,得到叠前AVO反演流程,并应用于实际的地震数据中,从而在提高地震数据分辨率的同时提高了AVO油气检测的精度。本文通过近地表吸收补偿及其在AVO分析中的应用研究,在提高地震数据分辨率的同时,合理的、定量的校正近地表影响,提高了AVO叠前反演精度,为有利区域和目标井位优选提供了可靠的数据保障。
[Abstract]:Low velocity drop near the surface brings a lot of adverse effects to high-precision seismic exploration. Relative to deep dense strata, the absorption and attenuation of seismic high-frequency signals in loose near-surface low-velocity zone is very serious, resulting in the change of lithologic space near the surface, and the serious spatial change of excitation energy and excitation wavelet. The change of seismic attribute information caused by the final imaging and reservoir reflection is much larger than that caused by geological and oil and gas factors. The quality factor Q itself reflects the physical characteristics of strata and rocks. In order to eliminate the dispersive absorption of seismic waves in the process of propagation in near-surface media and improve the resolution of seismic data, Inverse Q filter is an effective method for seismic wave compensation. In this paper, the factors affecting seismic wave propagation near the surface and the inverse Q filtering method are introduced, the physical mechanism and characteristics of absorption attenuation are analyzed, and the theoretical model of surface absorption attenuation is established. The Q value is quantitatively estimated by absorption compensation technique, and the method of constructing Q value field is obtained. Through the measurement of the near surface attenuation, the attenuation law is found, and the near surface absorption compensation method is obtained and the near surface absorption attenuation is compensated on this basis. Finally, through the AVO attribute analysis, the AVO processing model is established. The prestack AVO inversion process is obtained and applied to the actual seismic data, which improves the resolution of seismic data and improves the accuracy of AVO oil and gas detection. In this paper, the near surface absorption compensation and its application in AVO analysis are studied. At the same time, the resolution of seismic data is improved, and the near surface influence is corrected reasonably and quantitatively, and the precision of AVO prestack inversion is improved. It provides reliable data guarantee for favorable area and target well location selection.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4

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