地震资料叠前FVO技术分析及应用

发布时间：2018-04-13 02:32

本文选题：叠前 + FVO　；参考：《中国地质大学(北京)》2016年硕士论文

【摘要】：随着我国经济建设的高速发展,油气资源在国民经济中所占据的地位显著提高,国内油气勘探以及开发的难度也越来越大。因而油气的勘探与开发对勘探技术就有了更高层次的要求。地震波在地下传播的过程中,会受到多种因素而产生的吸收衰减作用的影响,最终使得地震波的高频成分被大量吸收,频率显著降低,其中地下地层中的油气流体便是其中一个重要因素,也是我们在地震勘探中的主要目标。但由于地下介质的横向非均质性强,单一的应用AVO反演有时并不能准确地预测地下地层的含油气性。传统的频率衰减属性分析是在叠加后进行的,但是经过叠加,频率衰减属性对流体的敏感性将会降低,将不利于对流体的预测。为解决以上问题,本文通过对AVO的理论公式的研究,选取了郑晓东的AVO抛物线计算公式做为原型,结合频率衰减的相关理论,推导并完善了FVO(频率衰减随偏移距的变化关系)的近似理论公式,从理论角度上证明了FVO属性可以用来预测地下油气等流体的贮藏情况。随后在该理论的指导下,本论文通过设计了两个不同的二维地质模型,利用模型叠前正演试验,证实了地下地层中含有流体时,地震波的频率确实将会发生严重的衰减。由此得知,通过叠前FVO属性来预测地下流体的空间展布具有较强的可行性。然后结合实际的原始叠前地震道集数据,经过资料的分析和处理,完成了对地下储层的叠前反演工作。分别提取了叠前AVO属性和叠前FVO属性,并对相应的属性图进行了分析。结合实际钻井资料最终发现,叠前FVO属性在实际的应用中也取得了较好的效果。验证了叠前FVO属性可以比较准确地反映地下流体的空间展布。以推导的理论公式、模型正演试验以及实际地震数据的验证效果为依据,可以发现叠前FVO属性对地下岩层中的流体比较敏感,当地震波在地下地层中传播时,频率衰减将随着偏移距的增大而增强;地下储层饱含油气等流体以后,频率衰减也会相应的增强;当饱含流体的储层厚度增加,同样会导致频率衰减的增强,但当储层厚度较小时,频率衰减可能十分微弱以至无法识别。总体来说,FVO属性预测地下流体具有很强的可行性。
[Abstract]:With the rapid development of China's economic construction, the status of oil and gas resources in the national economy has increased significantly, and the domestic oil and gas exploration and development is becoming more and more difficult.Therefore, the exploration and development of oil and gas have a higher level of requirements for exploration technology.In the process of underground seismic wave propagation, it will be influenced by the absorption and attenuation caused by many factors. Finally, the high frequency components of seismic wave will be absorbed in large quantities, and the frequency will be significantly reduced.The oil and gas fluid in underground formation is one of the important factors, and is also the main target in seismic exploration.However, due to the strong lateral heterogeneity of underground media, the single application of AVO inversion can not accurately predict the oil and gas properties of underground strata.The traditional frequency attenuation attribute analysis is carried out after superposition, but after superposition, the sensitivity of frequency attenuation attribute to fluid will be reduced, which will be unfavorable to the prediction of fluid.In order to solve the above problems, this paper selects Zheng Xiaodong's AVO parabola calculation formula as the prototype through the study of AVO's theoretical formula, and combines the related theory of frequency attenuation.The approximate theoretical formula of the variation of frequency attenuation with offset is derived and perfected. It is proved theoretically that the FVO attribute can be used to predict the storage of underground oil and gas and other fluids.Then, under the guidance of the theory, this paper designs two different two-dimensional geological models. By using the model prestack forward modeling test, it is proved that the frequency of seismic wave will indeed attenuate seriously when there is fluid in the underground formation.Therefore, it is feasible to predict the spatial distribution of underground fluid by prestack FVO attribute.Then the pre-stack inversion of the underground reservoir is completed through the analysis and processing of the data combined with the actual pre-stack seismic trace data.The prestack AVO attributes and prestack FVO attributes are extracted, and the corresponding attribute diagrams are analyzed.Combined with the actual drilling data, it is found that the prestack FVO attribute has also achieved good results in practical application.It is verified that the prestack FVO attribute can accurately reflect the spatial distribution of underground fluids.Based on the derived theoretical formula, model forward test and validation effect of actual seismic data, it can be found that prestack FVO attribute is sensitive to the fluid in underground strata, and when seismic wave propagates in underground strata,The frequency attenuation will increase with the increase of migration distance; the frequency attenuation will also increase when the underground reservoir is full of oil, gas and other fluids; when the reservoir thickness of the rich fluid increases, it will also lead to the increase of the frequency attenuation.However, when the reservoir thickness is small, the frequency attenuation may be so weak that it can not be identified.Generally speaking, it is feasible to predict underground fluid by FVO attribute.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P631.44

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