Surface-Based Modelling of Subsurface Reservoirs Using Parametric NURBS Surfaces
C. Jacquemyn, Y. Melnikova, M.D. Jackson and G.J. Hampson
Event name: 79th EAGE Conference and Exhibition 2017
Session: Building and Updating Subsurface 3D Models I
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 1.4Mb )
Price: € 20
A new surface-based geological modelling approach is developed to generate bounding surfaces based on NURBS (non-uniform rational B-splines) to represent geological heterogeneity of interest without imposing it on a predefined grid. The surfaces represent a broad range of heterogeneity types across a range of length-scales, including structural heterogeneity such as folds, faults or fractures, stratigraphic heterogeneity associated with sediment bodies of various scales and geometries (e.g. clinoforms, channelized features or build-ups) and boundaries between different facies or lithologies. Reservoir modelling using parametric NURBS surfaces has many advantages over conventional grid-based reservoir modelling approaches. A surface-based modelling approach overcomes issues related to geometrical complexity (e.g. non-monotonic surfaces) and representing heterogeneity over a range of length scales. The NURBS representation of these surfaces provides a computationally efficient way to represent their complex geometry. With a limited number of control points, complex and geometrically realistic surfaces can be created, with high level of detail where needed. Because NURBS form smooth surfaces, no stairstepping effects are introduced. The strength of NURBS surfaces lies in representing geologically-realistic complex heterogeneity explicitly across multiple scales.