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: 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: 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 (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 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.

Abstract: Systems and methods for predicting a stress attribute of a subsurface earth volume. One or more linearly independent far field stress models and one or more discontinuity pressure models may be simulated for the subsurface earth volume to generate stress values, strain values, displacement values, or a combination thereof for data points in the subsurface earth volume. A processor may be used to compute a superposition of the one or more linearly independent far field stress models and the one or more discontinuity pressure models. The stress attribute of the subsurface earth volume may be predicted, based on the computed stress values, strain values, displacement values, or the combination thereof.

Abstract: A method can include providing fault geometry data and fracture data for a fracture; estimating a parameter value of a far field stress based at least in part on the fault geometry data and the fracture data; and determining an undisturbed parameter value for the fracture. Various other apparatuses, systems, methods, etc., are also disclosed.

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.