宽方位角地震属性的提取方法研究

发布时间：2018-03-30 13:26

本文选题：宽方位角　切入点：各向异性　出处：《电子科技大学》2015年硕士论文

【摘要】：在石油勘探领域,常规的孔隙型油气藏资源已经越来越少,我国已经将勘探的重心转向了在我国存储量巨大的裂缝性油气藏。但是,裂缝型油气藏的孔隙度低、非均质性强,并且裂缝分布复杂,采用常规的勘探方法效果不是很理想,如何有效的开采裂缝型油气藏已经成为了地质勘探领域的一个公认的难题。本文采用了对裂缝预测有着较好效果的宽方位角地震资料,利用宽方位角地震资料的各项异性特征,将宽方位角地震资料与地震属性的优点相结合,得到能够更加准确的预测裂缝型油气藏的宽方位角地震属性。具体的创新工作如下:1、提出了宽方位角相干体和宽方位角方差体算法:宽方位角地震信号在非连续均匀的地质构造区域中传播时不同方向的同一道数据差异性会很大,这些差异性反映了地层下的非连续的地质结构。本文首次将相干体属性和方差体属性应用在宽方位角地震资料中,通过计算不同方向的同一道数据的相似性和差异性,得到了能够反演出地层中的断层、裂缝等地质结构的宽方位角相干体和宽方位角方差体。宽方位角相干体和宽方位角方差体相对于原始振幅切片和叠后相干体属性以及叠后方差体属性来说,对裂缝的预测效果更好。2、提出了宽方位角纹理属性算法:该算法利用宽方位角地震资料不同的角度的信号在经过断层、裂缝等地质构造时信号的传播速度和强度会有所不同的各项异性特性,先计算不同方位角地震属性的三个方向的梯度来得到这些数据体的结构差异,再由这些梯度数据体计算空间中每一点的相关性矩阵,最后根据每个点的相关性矩阵来得到一系列的可以预测地层下的断层、裂缝和溶洞、溶孔等地质结构的宽方位角纹理属性体,这些属性体与基于叠后地震资料的纹理属性体相比,对裂缝和断层的预测效果更好。3、提出了宽方位角曲率属性算法:该算法利用空间中的每个点在不同方位角的振幅值的差异性在空间中重新构造出一个三维空间曲面,在利用插值算法将三维空间曲面补齐之后,最后通过计算该曲面上中心点的曲率来得到目标点的曲率属性。将这些曲率属性体用于实际的地震资料中,对工区的特殊地质构造预测效果较好,达到了预期目标。最后通过在实际地震资料的应用,得到的各种宽方位角地震属性体与相同工区的常规叠后地震属性体做了比较,效果有明显提升,达到了预先所期望的效果。
[Abstract]:In the field of petroleum exploration, the conventional pore type oil and gas reservoir resources have been less and less, and our country has shifted the focus of exploration to the fractured oil and gas reservoir with huge storage capacity in our country. However, the porosity of the fractured reservoir is low and the heterogeneity is strong. Moreover, the distribution of fractures is complex, and the effect of conventional exploration methods is not ideal. How to effectively exploit fractured oil and gas reservoirs has become a recognized problem in the field of geological exploration. In this paper, the wide azimuth seismic data, which have good effect on fracture prediction, and the heterogeneity of wide azimuth seismic data are used. Combining wide azimuth seismic data with the advantages of seismic attributes, The seismic attributes of wide azimuth angle of fractured reservoirs can be obtained more accurately. The specific innovation work is as follows: 1. The algorithms of wide azimuth coherent volume and wide azimuth variance volume are proposed: wide azimuth seismic signal is discontinuous. The difference between the same data in different directions in a homogeneous geological structure region will be very large. These differences reflect the discontinuous geological structure under the stratum. In this paper, the coherent volume attribute and variance volume attribute are applied to the wide azimuth seismic data for the first time, and the similarity and difference of the same trace data in different directions are calculated. We get the ability to reverse the faults in the strata, The wide azimuth coherent volume and wide azimuth variance volume of the geological structure such as fractures. The wide azimuth coherent volume and wide azimuth variance volume are relative to the original amplitude slice and poststack coherent volume attributes as well as the poststack variance volume attributes. In this paper, a wide azimuth texture attribute algorithm is proposed, which uses the signals of different angles from the wide azimuth seismic data to pass through the fault. The signal propagation velocity and intensity will be different in geological structures such as fractures. The structural differences of these data bodies can be obtained by calculating the gradients in three directions of seismic attributes of different azimuth angles. Then the correlation matrix of each point in the space is calculated by these gradient data bodies. Finally, according to the correlation matrix of each point, a series of predicted faults, fractures and caverns under the strata can be obtained. The wide-azimuth texture attribute bodies of geological structures such as dissolved holes, which are compared with texture attribute bodies based on post-stack seismic data, For crack and fault prediction, a wide azimuth curvature attribute algorithm is proposed. The algorithm reconstructs a three-dimensional surface in space using the difference of amplitude values of each point in space at different azimuths. The curvature attribute of the target point is obtained by calculating the curvature of the center point on the surface after the interpolation algorithm is used to complement the three-dimensional space surface, and the curvature attribute body is used in the actual seismic data. The prediction effect of the special geological structure in the working area is better and the expected goal is achieved. Finally, through the application of the actual seismic data, the obtained seismic attribute bodies with wide azimuth angle are compared with the conventional post-stack seismic attribute bodies in the same work area. The effect is obviously improved, reaching the expected effect in advance.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4

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