Manzocchi Tom, Walsh Deirdre A, Carneiro Marcus, López-Cabrera Javier
iCRAG and Fault Analysis Group, UCD School of Earth Sciences, University College Dublin, Dublin 4, Ireland.
Math Geosci. 2023;55(5):625-644. doi: 10.1007/s11004-023-10048-y. Epub 2023 Feb 23.
Simple object- or pixel-based facies models use facies proportions as the constraining input parameter to be honored in the output model. The resultant interconnectivity of the facies bodies is an unconstrained output property of the modelling, and if the objects being modelled are geometrically representative in three dimensions, commonly-available methods will produce well-connected facies when the model net:gross ratio exceeds about 30%. Geological processes have more degrees of freedom, and facies in high net:gross natural systems often have much lower connectivity than can be achieved by object-based or common implementations of pixel-based forward modelling. The compression method decouples facies proportion from facies connectivity in the modelling process and allows systems to be generated in which both are defined independently at input. The two-step method first generates a model with the correct connectivity but incorrect facies proportions using a conventional method, and then applies a geometrical transform to scale the model to the correct facies proportions while retaining the connectivity of the original model. The method, and underlying parameters, are described and illustrated using examples representative of low and high connectivity geological systems.
简单的基于对象或像素的岩相模型使用岩相比例作为约束输入参数，以便在输出模型中得以体现。岩相体的最终连通性是建模的一个无约束输出属性，并且如果所建模的对象在三维空间中具有几何代表性，那么当模型的净毛比超过约30%时，常用方法将生成连通性良好的岩相。地质过程具有更多的自由度，并且在高净毛比的自然系统中，岩相的连通性通常比基于对象或基于像素的正向建模的常见实现所能达到的连通性要低得多。压缩方法在建模过程中将岩相比例与岩相连通性解耦，并允许生成在输入时两者都独立定义的系统。两步法首先使用传统方法生成一个连通性正确但岩相比例不正确的模型，然后应用几何变换将模型缩放到正确的岩相比例，同时保留原始模型的连通性。使用代表低连通性和高连通性地质系统的示例对该方法及相关基础参数进行了描述和说明。
