Surface-Based Geological Reservoir Modelling Using Grid-Free NURBS Curves and Surfaces
Surface-Based Geological Reservoir Modelling Using Grid-Free NURBS Curves and Surfaces
复制标题
使用无网格 NURBS 曲线和曲面进行基于表面的地质储层建模
DOI：
10.1007/s11004-018-9764-8
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发表时间：
2018
影响因子：
2.6
通讯作者：
G. Hampson
中科院分区：
文献类型：
--
作者：
C. Jacquemyn;M. Jackson;G. Hampson
在储层模型中建立地质非均质性的几何真实表示是一项具有挑战性的任务，其受到预定义的柱或角点网格的可扩展性的限制。基于表面的建模工作流程使用无网格表面，允许有效创建地质模型，而不受预定义网格的限制。基于表面的储层建模使用边界表示方法，其中所有感兴趣的非均质性（结构、地层、沉积、成岩）通过其边界表面建模，独立于任何网格。由这些表面界定的岩石内部是均匀的，因此，在这些地质区域内不进行额外的相或岩石物理建模，并且在建模期间不需要网格或网格离散化。通过添加表面，将在此类体积内建模的任何异质性合并。使用参数化非均匀有理B样条（NURBS）描述对曲面和曲线进行建模。这些表面是有效的生成和操纵，并允许快速创建几何上真实的储层模型的多个实现。引入多个层次的表面层次结构，以允许在所需的详细程度上对所有感兴趣的特征进行建模;构造一个层次结构的表面，以便截断或符合更高层次结构的表面。此过程需要曲面的连接、终止和堆叠，以确保模型包含“防水”曲面边界体积。NURBS曲线用于精确地表示井轨迹，包括多井眼轨迹或侧轨迹。一旦生成了所有的表面和威尔斯，它们就被组合到一个储层模型中，该模型考虑了表面之间的地质关系并保留了真实的几何形状。
Building geometrically realistic representations of geological heterogeneity in reservoir models is a challenging task that is limited by the inflexibility of pre-defined pillar or cornerpoint grids. The surface-based modelling workflow uses grid-free surfaces that allows efficient creation of geological models without the limitations of pre-defined grids. Surface-based reservoir modelling uses a boundary representation approach in which all heterogeneity of interest (structural, stratigraphic, sedimentological, diagenetic) is modelled by its bounding surfaces, independent of any grid. Volumes bounded by these surfaces are internally homogeneous and, thus, no additional facies or petrophysical modelling is performed within these geological domains and no grid or mesh discretisation is needed during modelling. Any heterogeneity to be modelled within such volumes is incorporated by adding surfaces. Surfaces and curves are modelled using a parametric non-uniform rational B-splines (NURBS) description. These surfaces are efficient to generate and manipulate, and allow fast creation of multiple realisations of geometrically realistic reservoir models. Multiple levels of surface hierarchy are introduced to allow modelling of all features of interest at the required level of detail; surfaces at one hierarchical level are constructed so as to truncate or conform to surfaces of a higher hierarchical level. This procedure requires the joining, terminating and stacking of surfaces to ensure that models contain “watertight” surface-bounded volumes. NURBS curves are used to represent well trajectories accurately, including multi-laterals or side-tracks. Once all surfaces and wells have been generated, they are combined into a reservoir model that takes into account geological relationships between surfaces and preserves realistic geometries.