Abstract: Systems, methods, and software can be used to simulate a fracture treatment. In some aspects, a common solution vector for multiple distinct subsystem models is defined. Each subsystem model represents a distinct subsystem of an injection treatment system. Parameters of the subsystem models are updated based on the solution vector according to predefined relationships between the solution vector and the parameters of the subsystem models. The subsystem models are operated based on the solution vector and the updated parameters.

Abstract: Techniques for evaluating a fluid flow through a wellbore include identifying an input characterizing a fluid flow through a wellbore; identifying an input characterizing a geometry of the wellbore; generating a model of the wellbore based on the inputs characterizing the fluid flow and the geometry of the wellbore; simulating the fluid flow through the wellbore based on evaluating the model with a numerical method that determines fluid flow conditions at a first boundary location uphole and adjacent to a perforation of a plurality of perforations in the wellbore and at a second boundary location downhole and adjacent to the perforation; and preparing, based on the fluid flow conditions determined with the numerical method, an output associated with the simulated fluid flow through the wellbore for display to a user.

Abstract: Systems, methods, and software can be used to simulate a fracture treatment. In some aspects, physically separate rock blocks of a subterranean zone are modeled by separate block models. The block model for each physically separate rock block represents intra-block mechanics of the rock block, for example, as a group of discrete block elements. Interactions between adjacent pairs of the rock blocks are modeled by separate joint models. The joint model for each adjacent pair of rock blocks represents inter-block mechanics between the adjacent rock blocks, for example, as pre-defined joints. The block models and joint models are used to simulate an injection treatment of the subterranean zone.

Abstract: In some aspects, techniques and systems for operating a subterranean region model are described. A global system model represents a subterranean region. A global coefficient matrix of the global system model can be identified. The global system includes preconditioned subsystem models. Each of the subsystem models represents a distinct subsystem within the subterranean region and is associated with a respective governing equation. Eigenvalues of the global coefficient matrix can be shifted by a regularization parameter. Shifting the eigenvalues of the global coefficient matrix generates a shifted global coefficient matrix. A solution to a shifted global system that includes the shifted global coefficient matrix can be obtained. The global system model can be solved based on the solution to the shifted global system.

Abstract: In some aspects, techniques and systems for operating a subterranean region model are described. A global system model represents a subterranean region. Subsystem models of the global system model are identified. Each of the subsystem models represents a distinct subsystem within the subterranean region and is associated with a respective governing equation. The subsystem models can be preconditioned based on the respective governing equations of the subsystem models. The global system model that includes the preconditioned subsystem models can be preconditioned. The preconditioned global system model can be operated.

Abstract: Systems, methods, and software can be used to simulate a fracture treatment. In some aspects, a common solution vector for multiple distinct subsystem models is defined. Each subsystem model represents a distinct subsystem of an injection treatment system. Parameters of the subsystem models are updated based on the solution vector according to predefined relationships between the solution vector and the parameters of the subsystem models. The subsystem models are operated based on the solution vector and the updated parameters.

Abstract: Systems, methods, and software can be used to simulate a fracture treatment. In some aspects, physically separate rock blocks of a subterranean zone are modeled by separate block models. The block model for each physically separate rock block represents intra-block mechanics of the rock block, for example, as a group of discrete block elements. Interactions between adjacent pairs of the rock blocks are modeled by separate joint models. The joint model for each adjacent pair of rock blocks represents inter-block mechanics between the adjacent rock blocks, for example, as pre-defined joints. The block models and joint models are used to simulate an injection treatment of the subterranean zone.

Abstract: Techniques for evaluating a fluid flow through a wellbore include identifying an input characterizing a fluid flow through a wellbore; identifying an input characterizing a geometry of the wellbore; generating a model of the wellbore based on the inputs characterizing the fluid flow and the geometry of the wellbore; simulating the fluid flow through the wellbore based on evaluating the model with a numerical method that determines fluid flow conditions at a first boundary location uphole and adjacent to a perforation of a plurality of perforations in the wellbore and at a second boundary location downhole and adjacent to the perforation; and preparing, based on the fluid flow conditions determined with the numerical method, an output associated with the simulated fluid flow through the wellbore for display to a user.