GeoModel: Mutable object composition to represent Geological Model

The key feature of RINGMesh is the RINGMesh::GeoModel. It aims at representing a geological model with a level of complexity adapted to the problem to solve. Geological objects are complex and multiscale.

• The first way to represent and discretize a high level of detail is to use a mesh composition of Entities called RINGMesh::GeoModelEntities. In this case, the RINGMesh::GeoModel defines the boundary representation of major geological objects holding the discretization and connectivity between Entities.
• The second way to deal with the geological model is to consider the global geometry through a single mesh. The RINGMesh::GeoModel have that ability to build a RINGMesh::GeoModelMesh on the fly. In this object, every node, edge, polygon and cell can be assessed through a global index. It also enables a duplication of nodes along surfaces. This is useful to feed some physical simulators and export several data structure formats.

GeoModel Constitutive Elements: GeoModelEntity

A model is defined by its constitutive elements RINGMesh::GeoModelEntity. There are two main kinds of entities (see figure below):

• Geometrical entities that define the geometry of the model through several dimensions:
  • Regions
  • Surfaces
  • Lines
  • Corners
• Geological entities that group several geometrical entities according to their geological meaning:
  • Layers
  • Interfaces
  • Contacts

Figure: Geomodel entities divided into the geometrical entities and the geological entities. Figure from Pellerin et al. (2017).

We know that this is not a complete list. A lot of entities would be valuable to complete the model. We strongly encourage people to contribute and complete these lists :)

GeoModel Geometrical Entities: GeoModelMeshEntity

A set of RINGMesh::GeoModelMeshEntity holds the discretization and the boundary representation of the geological model. Each mesh entity knows all connected higher and lower dimension mesh entities. Even if the topology between Entities is known, each RINGMesh::GeoModelMeshEntity stores its own mesh data structure independently of each other and you cannot get any global information. Geometrical information is contained by an abstract mesh class implemented in RINGMesh. This abstraction level is a strength of RINGMesh because it can be adapted to any data structure and eases the coupling between softwares (more details about meshes).

• A RINGMesh::Region is a volume defined by a set of RingMesh::Surface creating a closed "box". Every surface that bounds a region can be accessed by its index. A region can be meshed with cells.
• A RINGMesh::Surface is defined by a set of RINGMesh::Line creating a closed curve. It defines one border of a RINGMesh::Region. Neighboring lines and surfaces can be accessed by their indices.
• A RINGMesh::Line is defined by two RINGMesh::Corner. Connected corners and surfaces can be accessed by their indices.
• A RINGMesh::Corner is a single node that bounds a RingMesh::Line. Connected lines can be accessed by their indices.

GeoModel Geological Entities: GeoModelGeologicalEntity

A RINGMesh::GeoModelGeologicalEntity stores a geological-based topological structure. It uses a kind of parent/child implementation where RINGMesh::GeoModelGeologicalEntity is the parent of its children RINGMesh::GeoModelMeshEntity. The main idea is to cluster several geometrical entities that compose a geological object.

• RINGMesh::Layer is composed by several RINGMesh::Region. A layer is the parent of several children regions. It represents a geological layer.
• RINGMesh::Interface is composed by several RINGMesh::Surface. An interface is the parent of several children surfaces. It represents a geological object such as a fault or a horizon.
• A RINGMesh::Contact (parent) is composed by several RINGMesh::Line (children). It corresponds to the intersection between two RINGMesh::Interface.

GeoModel Global Representation: GeoModelMesh

The GeoModelMesh is one mesh built by copying and merging all RINGMesh::GeoModelMeshEntity of the GeoModel in a global and unique mesh. It allows to access to (1) a more general information than the one stored inside the mesh of RINGMesh::GeoModelEntity, and (2) a single mesh representing the entire geological model.

To ease the global access to vertices, edges, facets and cells without redundancy at GeoModel geometrical entity borders; four databases are available. These databases are empty by default and are automatically filled as soon as they are used.

• The RINGMesh::GeoModelMeshVertices gives a global and unique access to any vertex of the GeoModel.
• The RINGMesh::GeoModelMeshEdges gives a global and unique access to any edge and adjacent edges of each GeoModel contacts.
• The RINGMesh::GeoModelMeshPolygons gives a global and unique access to any polygon and adjacent polygons of each GeoModel interfaces.
• The RINGMesh::GeoModelMeshCells gives a global access to any cell and its adjacent cells. At the mesh interfaces cells can be either connected or disconnected. Several disconnection modes are available according to the geologic features.
  • No Duplication
  • Duplication along faults only
  • Duplication along horizons only
  • Duplication along faults and horizons
• The RINGMesh::GeoModelMeshWells is a particular database to ease the iteration on well geometry. It provides a global and unique access to any edge and adjacent edges of wells.