Abstract: A computer-implemented geological modeling method is disclosed. Hydraulic fracturing includes pumping fluids through a wellbore/casing and into a formation through perforations, creating fractures that can improve well productivity. Geological modeling may be used to model pumping of fluids into the subsurface to achieve a desired fracturing result. However, the grid used may affect the fracture propagation calculations used for geological modeling. Thus, a methodology is disclosed which reduces the grid dependence when determining various aspects of fracturing, such as pressure and/or aperture. The methodology uses a first correction factor that is based on the grid used to determine fracture propagation and a second correction factor that is not based on the grid used to determine fracture propagation (such as based on an ideal grid). In this way, the two correction factors are derived from different aspects, which when combined, may be used to reduce grid dependence when determining fracture propagation.

Abstract: Geologic modeling methods and systems disclosed herein employ an improved simulation gridding technique that optimizes simulation efficiency by balancing the computational burdens associated with remeshing against the performance benefits of doing so. One method embodiment includes: (a) obtaining a geologic model representing a subsurface region as a mesh of cells, at least some of the cells in the mesh having one or more interfaces representing boundaries of subsurface structures including at least one fracture; (b) determining a fracture extension to the at least one fracture; (c) evaluating whether the fracture extension is collocated with, or is proximate to, an existing cell interface, and using the existing cell interface if appropriate or creating a new cell interface if not; and (d) outputting the updated version of the geologic model.

Abstract: A method for generating a three-dimensional geomechanical model of a subsurface volume is provided. The geomechanical model may be used to predict changes in geomechanical stress in the grid (such as a three-dimensional unstructured grid), which may be caused by extraction from or injection into the reservoir. The geomechanical model may be generated by solving, in combination, the finite element method at the vertices of a respective cell in the grid for momentum balance and the finite volume method at the center of the respective cell for mass balance. In this way, one or both of rock displacement or pore flow may be solved using the geomechanical model.

Abstract: Geologic modeling methods and systems disclosed herein employ an improved simulation gridding technique that optimizes simulation efficiency by balancing the computational burdens associated with remeshing against the performance benefits of doing so. One method embodiment includes: (a) obtaining a geologic model representing a subsurface region as a mesh of cells, at least some of the cells in the mesh having one or more interfaces representing boundaries of subsurface structures including at least one fracture; (b) determining a fracture extension to the at least one fracture; (c) evaluating whether the fracture extension is collocated with, or is proximate to, an existing cell interface, and using the existing cell interface if appropriate or creating a new cell interface if not; and (d) outputting the updated version of the geologic model.