Abstract: A method for predicting a stress attribute of a subsurface earth volume includes simulating a linearly independent far field stress model, a discontinuity pressure model, and a discontinuity pressure shift model for the subsurface earth volume. A stress value, a discontinuity pressure shift at a surface of the Earth, a strain value, a displacement value, or a combination thereof is computed for data points in the subsurface earth volume based on a superposition of the linearly independent far field stress model, the discontinuity pressure models, and the discontinuity pressure shift model. The stress attribute of the subsurface earth volume is predicted, based on the computed stress value, the computed discontinuity pressure shift at the surface of the Earth, the computed strain value, the computed displacement value, or the combination thereof.

Abstract: A method of simulating a process of a geological structure includes obtaining a first digital model including structural data representing a geological structure. The method also includes selecting at least one marching technique based in part on a grid dimension and a grid cell shape of a grid on the first digital model. The method further includes applying the at least one marching technique to at least a portion of the structural data of the first digital model to identify at least some boundary data. The method further includes populating a second digital model based in part on the first digital model, a property, and the boundary data. The method further includes simulating a process of the geological structure using the second digital model.

Abstract: Methods, computing systems, and computer-readable media for modeling a subterranean volume, of which the methods include receiving data representing a geology of the subterranean volume, calculating a mesh for a digital model of the subterranean volume, generating the digital model using the mesh and the data, wherein generating the digital model comprises defining an implicit function for isostratigraphic surfaces of the subterranean volume. calculating values for a plurality of data points in the model using the implicit function, determining a discrepancy value for the individual data points, identifying a sample domain in the digital model, determining a refined implicit function for the sample domain, and modeling the subterranean volume using the refined implicit function for the sample domain and the implicit function for an area outside of the sample domain in the digital model.

Abstract: A method can include receiving spatially located geophysical data of a geologic region as acquired by one or more sensors; solving a system of equations for multi-dimensional implicit function values within a multi-dimensional space that represents the geologic region where the system of equations are subject to a smoothness constraint and subject to a weighted curvature minimization criterion at a plurality of spatially located points based on the spatially located geophysical data; and rendering to a display, a structural model of the geologic region based at least in part on the multi-dimensional implicit function values where the structural model characterizes stratigraphy of the geologic region.

Abstract: Provided are a method, computer-readable medium, and a system for determining rupture envelopes for a fault system. The method includes obtaining a representation that depicts one or more faults in a region of the earth as triangulated surfaces; selecting variables from among parameters comprising stress ratio, orientation of far field stress maximum principal stress, intermediate principal stress, minimum principal stress for the far field stress, and sliding friction and cohesion of the fault system; determining a strain energy of a triangular element based on a friction coefficient, a normal stress on the triangular element, and a cohesion for the variables; summing the strain energy of each triangle in the triangulated surfaces to yield an effective shear strain energy; extracting one or more iso-surfaces of the effective shear strain energy based on the summing; and creating rupture envelopes for specific values of the effective shear strain energy.

Abstract: A method (710) can include receiving data for fractures associated with a geologic environment (712); performing stress inversion, based at least in part on a portion of the data and assignment of different mechanical fracture types to different populations of the fractures, to recover tectonic stress (716); and outputting the tectonic stress (720).

Abstract: A method, apparatus, and program product utilize projection-based area operations to accelerate the determination of subsurface structure parameters for subsurface structures such as fractures, faults and horizons in a subsurface formation.

Abstract: Methods, computing systems, and computer-readable media for modeling a subterranean volume, of which the methods include receiving data representing a geology of the subterranean volume, calculating a mesh for a digital model of the subterranean volume, generating the digital model using the mesh and the data, wherein generating the digital model comprises defining an implicit function for isostratigraphic surfaces of the subterranean volume. calculating values for a plurality of data points in the model using the implicit function, determining a discrepancy value for the individual data points, identifying a sample domain in the digital model, determining a refined implicit function for the sample domain, and modeling the subterranean volume using the refined implicit function for the sample domain and the implicit function for an area outside of the sample domain in the digital model.

Abstract: Provided are a method, computer-readable medium, and a system for determining rupture envelopes for a fault system. The method includes obtaining a representation that depicts one or more faults in a region of the earth as triangulated surfaces; selecting variables from among parameters comprising stress ratio, orientation of far field stress maximum principal stress, intermediate principal stress, minimum principal stress for the far field stress, and sliding friction and cohesion of the fault system; determining a strain energy of a triangular element based on a friction coefficient, a normal stress on the triangular element, and a cohesion for the variables; summing the strain energy of each triangle in the triangulated surfaces to yield an effective shear strain energy; extracting one or more iso-surfaces of the effective shear strain energy based on the summing; and creating rupture envelopes for specific values of the effective shear strain energy.

Abstract: A method for predicting a stress attribute of a subsurface earth volume includes simulating a linearly independent far field stress model, a discontinuity pressure model, and a discontinuity pressure shift model for the subsurface earth volume. A stress value, a discontinuity pressure shift at a surface of the Earth, a strain value, a displacement value, or a combination thereof is computed for data points in the subsurface earth volume based on a superposition of the linearly independent far field stress model, the discontinuity pressure models, and the discontinuity pressure shift model. The stress attribute of the subsurface earth volume is predicted, based on the computed stress value, the computed discontinuity pressure shift at the surface of the Earth, the computed strain value, the computed displacement value, or the combination thereof.

Abstract: A method can include receiving spatially located geophysical data of a geologic region as acquired by one or more sensors; solving a system of equations for multi-dimensional implicit function values within a multi-dimensional space that represents the geologic region where the system of equations are subject to a smoothness constraint and subject to a weighted curvature minimization criterion at a plurality of spatially located points based on the spatially located geophysical data; and rendering to a display, a structural model of the geologic region based at least in part on the multi-dimensional implicit function values where the structural model characterizes stratigraphy of the geologic region.

Abstract: A method, apparatus, and program product evaluate fracture abundance in a subsurface formation by modeling a fracture network in a three-dimensional volume using geometric primitives. A fracture abundance parameter, e.g., a P32 fracture density, may be determined in part based upon the combined areas of the primitives with cells of a three-dimensional grid.

Abstract: A method can include sampling points for at least a portion of a model of a geologic environment; generating a meshless model based at least in part on the points where the points correspond to nodes having respective domains of influence; and, based at least in part on the meshless model, computing a tensor field associated with forces experienced by at least a portion of the nodes. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: A method (710) can include receiving data for fractures associated with a geologic environment (712); performing stress inversion, based at least in part on a portion of the data and assignment of different mechanical fracture types to different populations of the fractures, to recover tectonic stress (716); and outputting the tectonic stress (720).

Abstract: A method, apparatus, and program product utilize projection-based area operations to accelerate the determination of subsurface structure parameters for subsurface structures such as fractures, faults and horizons in a subsurface formation.

Abstract: A method, apparatus, and program product evaluate fracture abundance in a subsurface formation by modeling a fracture network in a three-dimensional volume using geometric primitives. A fracture abundance parameter, e.g., a P32 fracture density, may be determined in part based upon the combined areas of the primitives with cells of a three-dimensional grid.

Abstract: A method can include receiving a system of equations with associated variables that describe physical phenomena associated with a geologic formation; representing a matrix for the system of equations as a tree of blocks; classifying a portion of the blocks as being near blocks and another portion of the blocks as being far blocks; and based on the classification of the near blocks, computing a preconditioner for an iterative solver for solving the system of equations.

Abstract: A method for predicting fault activity of a subsurface volume includes obtaining a model of the subsurface volume based on far field stress tensors, identifying faults in the subsurface volume, generating results corresponding to sole contribution from a fault for each of the far field stress tensors, selectively combining, for each of the far field stress tensors and based on a fault activity Boolean vector, the results as scaled linearly independent contribution to a superpositioned result, calculating a cost function representing a difference between the superpositioned result and a measurement of the subsurface volume, and minimizing the cost function by iteratively adjusting an optimization parameter for each far field stress tensors and iteratively adjusting the fault activity Boolean vector, to generate a prediction of the fault activity of the subsurface volume.

Abstract: A method for predicting regional stress of a subsurface volume includes obtaining a model matrix of the subsurface volume representing a relationship between a modeled fault slip result generated by a model and a boundary condition applied to the model, the boundary condition having a regional stress attribute and a fault friction attribute, calculating, using the model, the modeled fault slip result based on a selected value of the stress attribute and a selected value of the friction attribute, calculating a cost function representing a difference between the modeled fault slip result and a measurement of the subsurface volume, and minimizing the cost function by iteratively adjusting at least the selected value of the stress attribute to generate a prediction of the regional stress of the subsurface volume.

Abstract: Stress and fracture modeling using the principal of superposition is provided. A system simulates linearly independent far field stress models for a subsurface earth volume, computing stress, strain, and displacement values based on superposition of independent stress tensors. Based on the precomputed values, the system generates real-time recovery of paleostress values, or, stress, strain, and displacement parameters for any point in the subsurface volume as the user varies far field stress values. The system recovers one or more tectonic events, or a stress tensor represented by a ratio of principal magnitudes and associated orientation, using fault geometry, well bore data (fracture orientation and secondary fault plane data), GPS, InSAR, folded and faulted horizons, tiltmeters, slip and slikenlines on faults.