深层叠前反演与储层评价

发布时间：2018-07-18 13:15

【摘要】：随着浅层、常规油气资源获取难度的增大,发展针对深层、超深层与非常规油气储层的地震勘探技术越来越成为人们关注的热点。杨氏模量、泊松比、体积模量与剪切模量等是表征岩体性质与流体信息重要的弹性参数。通过对储层岩石的弹性参数做定量估计,可以预测岩石和流体的性质,如孔隙度、泥质含量、以及含水饱和度等这些信息对于油气储层的评价以及后续的勘探、开发工作都非常关键。叠前AVO反演技术是当前油气勘探领域最重要的分析方法之一,也是获取地下介质弹性参数的重要手段,该技术的核心是描述地震波反射传播规律的反射系数方程。相较于中浅部勘探目标而言,针对深层勘探目标的地震叠前资料常缺失远角道集数据,使三参数AVO反演方程提取的参数矩阵面临较大的不稳定性,并且将由此产生的误差传递到最终的反演数据体中,降低反演弹性参数的准确性与可靠性。基于以上原因,本文在反射波法AVO理论的基础上,通过推导岩石物理弹性参数关系,发展出两种适用于深层—超深层油气储层,能够直接反演杨氏模量、泊松比、体积模量、剪切模量的两项式反射系数方程,构建相应反演技术,并据此对实际地震勘探资料进行AVO叠前反演,完成储层评价。具体说来,本文完成如下工作:(1)研究AVO反演基本理论,讨论关键岩石物理弹性参数之间的关系,然后在此基础上,通过合理建立速度与密度的关系,发展出可以直接反演杨氏模量、泊松比的两项式AVO反射系数近似方程,并利用模型与测试数据证明了新方法的可靠性;(2)在(1)的基础上建立直接反演体积模量、剪切模量的两项式AVO方程,并引入基于以上两种弹性参数的流体识别因子。模型数据试算和测试地震数据反演都表明新方法对于储层流体检测的有效性;(3)杨氏模量与泊松比可表征岩石的脆性,体积模量与剪切模量合成的流体因子对储层流体有较强的敏感性。综合利用本文发展的反演方法对缺失远角道集的叠前地震数据做AVO反演,从岩性与流体两方面完成实际工区的储层评价,解释结果与测井资料和实际开发情况吻合较好,表现出本文研究的理论与实际应用价值。
[Abstract]:With the increasing difficulty of obtaining conventional oil and gas resources in shallow layers, the seismic exploration technology for deep, ultra-deep and unconventional oil and gas reservoirs has become a hot topic. Young's modulus, Poisson's ratio, volume modulus and shear modulus are important elastic parameters to characterize the properties of rock mass and fluid information. By quantitatively estimating the elastic parameters of reservoir rocks, it is possible to predict the properties of rocks and fluids, such as porosity, shale content, and water saturation, for the evaluation and subsequent exploration of oil and gas reservoirs. Development is critical. Pre-stack AVO inversion technique is one of the most important analytical methods in the field of oil and gas exploration, and is also an important means to obtain elastic parameters of underground media. The core of this technique is the reflection coefficient equation which describes the law of seismic wave reflection and propagation. Compared with mid-shallow exploration targets, the seismic prestack data of deep exploration targets often lack far-angle gather data, which makes the parameter matrix extracted by three-parameter AVO inversion equation more unstable. The resulting errors are transferred to the final inversion data volume to reduce the accuracy and reliability of the inversion elastic parameters. For the above reasons, based on the AVO theory of reflection wave method and by deducing the relation of rock physical elastic parameters, two kinds of reservoir are developed, which can directly invert Young's modulus, Poisson's ratio and volume modulus. Based on the reflection coefficient equation of shear modulus, the corresponding inversion technique is constructed, and the AVO prestack inversion of the actual seismic exploration data is carried out to complete the reservoir evaluation. Specifically, the work of this paper is as follows: (1) the basic theory of AVO inversion is studied, and the relationship between the key rock physical and elastic parameters is discussed, and then the relationship between velocity and density is reasonably established. An approximate equation of AVO reflection coefficient which can directly inverse Young's modulus and Poisson's ratio is developed, and the reliability of the new method is proved by using the model and test data. (2) on the basis of (1), the direct inversion of volume modulus is established. The AVO equation of shear modulus and the fluid identification factor based on the above two elastic parameters are introduced. Both model data and seismic data inversion show that the new method is effective for reservoir fluid detection. (3) Young's modulus and Poisson's ratio can characterize the brittleness of rock. The fluid factors combined with volume modulus and shear modulus are sensitive to reservoir fluids. Using the inversion method developed in this paper, the AVO inversion of prestack seismic data with missing far-angle gathers is made, and the reservoir evaluation of the actual working area is completed from the lithology and fluid aspects. The interpretation results are in good agreement with the logging data and the actual development situation. It shows the theoretical and practical application value of this paper.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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