多年来,振幅随偏移距的变化(AVO)已成功地应用于预测储层性质和流体含量。在某些情况下,还能预测气—水和气—油界面的空间位置。在本文中,我们将证明,三维AVO技术也可用于裂缝性储层的描述,确定裂纹密度变化的空间分布。 新墨西哥San Juan盆地的Cedar Hill油田在Fruitland组的裂缝性煤层中出产甲烷。因为煤不具有原生渗透率,所以裂缝的存在是至关重要的。为了帮助对该煤储层进行描述,在该油田进行了一次三维三分量地震勘探。在本项研究中,我们采用多分量数据集中的叠前P波振幅资料,确定煤甲烷储层中的泊松比差(或裂纹密度)大的区域,用震源—检波器方位角选排探测由煤的断裂系统引起的方位各向异性的优先方向。 我们采用两种模拟方法(射线追踪法和反射系数法)预测了裂缝性煤层带对依赖于角度的P波反射系数的影响。用声波和密度测井确定的弹性参数建立了一个水平层状地质模型,并用该模型生成了一个合成共中心点(CMP)道集。煤层的裂缝密度变化用各向异性模型来模拟。砂岩一煤界面形成的大波阻抗差支配了P波反射率响应,其影响远远超过计算模型中各向异性参数的效应。 从三维数据体中抽取的9个共反射宏面元的地震AVO分析证实了模型预测的结果。AVO截距大的地区对应于煤层的低速区,它们有可能与应力释放区有? Over the years, the variation of amplitude with offset (AVO) has been successfully used to predict reservoir properties and fluid contents. In some cases, the spatial location of gas-water and gas-oil interfaces can also be predicted. In this article, we show that the 3D AVO technique can also be used to describe fractured reservoirs and determine the spatial distribution of changes in crack density. The Cedar Hill field in the San Juan Basin, New Mexico, produces methane in the fractured seam of the Fruitland Formation. Because coal does not have native permeability, the presence of cracks is crucial. To help describe the coal reservoir, a three-dimensional three-component seismic survey was conducted in the field. In this study, we use the pre-stack P-wave amplitude data in the multicomponent data set to determine areas with large Poisson’s ratio (or crack density) in coal-methane reservoirs. We use the source-detector azimuth pick and place The preferential direction of azimuthal anisotropy caused by the rupture system of coal. We use two simulation methods (ray tracing method and reflection coefficient method) to predict the influence of fractured coal seam on the reflection coefficient of angle-dependent P wave. A horizontal layered geological model was established using the acoustic parameters determined by acoustic and density logging and a synthetic central point (CMP) gathers was generated using this model. The variation of fracture density in the coal seam is modeled by an anisotropic model. The large wave impedance difference formed at the interface of sandstone and coal dominates the reflectivity response of P wave, whose influence far exceeds the effect of the anisotropic parameter in the calculation model. Seismic AVO analysis of nine co-reflecting macro-elements extracted from a three-dimensional data body confirmed the results of the model prediction. Areas with large AVO intercepts correspond to low velocity zones of the coal seam, and are they likely to have areas of stress release?