Computer-implemented systems and methods for use in modeling a geomechanical reservoir system

1. A computer-implemented method for use in modeling a geomechanical reservoir system, comprising:

receiving, through a computer system, data indicative of physical properties associated with the geomechanical reservoir system;

generating, through a computer system, fracturing predictions by solving a system of partial differential equations that model the geomechanical reservoir system;

wherein the system of partial differential equations comprises a reservoir flow model, a geomechanical model, and a fracture model of the geomechanical reservoir system;

wherein the system of partial differential are coupled through a fully-expanded Jacobian;

wherein the solving of the system of partial differential equations comprises solving simultaneously in a single timestep the fully-expanded Jacobian based upon the received physical properties data; and

wherein the fracturing predictions model the geomechanical reservoir system for the timestep; and

outputting or displaying, through a computer system, the generated fracturing predictions.

2. The method of claim 1 , wherein a coupling variable in the fully-expanded Jacobian that couples fluid flow in the reservoir to the geomechanical model is at least one of an effective stress, a porosity and one or more displacements associated with the geomechanical model, wherein a coupling variable in the fully-expanded Jacobian that couples the geomechanical model to the fluid flow is at least one of a porosity and a permeability associated with the reservoir flow model, wherein a coupling variable in the fully-expanded Jacobian that couples the geomechanical model to the fracture model is a fracture width associated with the fracture model, and wherein a coupling variable in the fully-expanded Jacobian that couples fluid flow in the reservoir to the fracture model is a fluid pressure and a leakoff rate associated with the fracture model.

3. The method of claim 2 , wherein the fully-expanded Jacobian comprises a partial time derivative, a time derivative, a spatial derivative, or a partial spatial derivative of at least one coupling variable.

4. The method of claim 3 , wherein the fully-expanded Jacobian comprises a partial time derivative, a time derivative, a spatial derivative, or a partial spatial derivative of the fracture width.

5. The method of claim 1 , wherein the system of partial differential equations further comprises a thermal model of the geomechanical reservoir system.

6. The method of claim 5 , wherein a coupling variable in the fully-expanded Jacobian that couples the thermal model to the geomechanical model is a thermal stress associated with the thermal model, and wherein a coupling variable in the fully-expanded Jacobian that couples the thermal model to the reservoir flow model is at least one of a fluid viscosity, a conduction and a convection in the reservoir associated with the thermal model.

7. A computer-implemented method for use in modeling a fracture in a geomechanical reservoir system, comprising:

receiving, through a computer system, data indicative of physical properties associated with the geomechanical reservoir system;

defining, through a computer system, a three-dimensional grid comprising a plurality of three-dimensional cells, wherein each of the three-dimensional cells comprises a plurality of nodes;

defining, through a computer system, a two-dimensional grid comprising a plurality of two-dimensional cells, wherein each of the two-dimensional cells comprises a plurality of nodes, and wherein each of the two-dimensional cells shares at least four nodes with a three-dimensional cell;

generating, through a computer system, fracturing predictions by solving a system of partial differential equations that model the geomechanical reservoir system;

wherein the system of partial differential equations comprises a reservoir flow model, a geomechanical model, and a fracture model of the geomechanical reservoir system;

wherein the system of partial differential are coupled through a fully-expanded Jacobian;

wherein the solving of the system of partial differential equations comprises solving simultaneously in a single timestep the fully-expanded Jacobian based upon the received physical properties data;

wherein the reservoir model and the geomechanical model are computed on the three-dimensional grid; and

wherein the fracture model is computed on the two-dimensional grid; and

wherein the fracturing predictions model the geomechanical reservoir system for the timestep; and

outputting or displaying, through a computer system, the generated fracturing predictions.

8. The method of claim 7 , wherein a coupling variable in the fully-expanded Jacobian that couples fluid flow in the reservoir to the geomechanical model is at least one of an effective stress, a porosity and one or more displacements associated with the geomechanical model, wherein a coupling variable in the fully-expanded Jacobian that couples the geomechanical model to the fluid flow is at least one of a porosity and a permeability associated with the reservoir flow model, wherein a coupling variable in the fully-expanded Jacobian that couples the geomechanical model to the fracture model is a fracture width associated with the fracture model, and wherein a coupling variable in the fully-expanded Jacobian that couples fluid flow in the reservoir to the fracture model is a fluid pressure and a leakoff rate associated with the fracture model.

9. The method of claim 8 , wherein the fully-expanded Jacobian comprises a partial time derivative, a time derivative, a spatial derivative, or a partial spatial derivative of at least one coupling variable.

10. The method of claim 9 , wherein the fully-expanded Jacobian comprises a partial time derivative, a time derivative, a spatial derivative, or a partial spatial derivative of the fracture width.

11. The method of claim 7 , wherein the system of partial differential equations further comprises a thermal model of the geomechanical reservoir system.

12. The method of claim 11 , wherein a coupling variable in the fully-expanded Jacobian that couples the thermal model to the geomechanical model is a thermal stress associated with the thermal model, and wherein a coupling variable in the fully-expanded Jacobian that couples the thermal model to the reservoir flow model is at least one of a fluid viscosity, a conduction and a convection in the reservoir associated with the thermal model.

13. The method of claim 7 , wherein each of the three-dimensional cell shares an interface with another three-dimensional cell, and wherein each the two-dimensional cell aligns with an interface of a three-dimensional cell.

14. The method of claim 7 , wherein solving of the system of partial differential equations comprises applying a Newton-Raphson technique.

15. The method of claim 7 , wherein a fracture width associated with the fracture model is determined from one or more displacements in the geomechanical model, the method further comprising a step of applying a fracture propagation criterion to the generated fracture predictions prior to outputting or displaying, through the computer system, the generated fracturing predictions.

16. The method of claim 15 , further comprising, if the fracture propagation criterion is not satisfied:

modifying one or more constraints on one or more nodes of the two-dimensional grid on a boundary of the fracture; and

repeating the step of generating, through the computer system, the fracturing predictions.

17. The method of claim 15 , wherein the fracture propagation criterion is based on a stress intensity factor or cohesive elements.

18. The method of claim 15 , wherein applying the fracture propagation criterion comprises evaluating the fluid pressure, stress, and displacements near the fracture to determine if the fracture propagates.

19. A computer-implemented system for use in modeling a geomechanical reservoir system, the system comprising:

one or more data structures resident in a memory for storing data representing a two-dimensional grid and a three-dimensional grid; and

software instructions, for executing on one or more data processors, to generate the fracturing predictions by solving a system of partial differential equations that model the geomechanical reservoir system; wherein:

the system of partial differential equations comprises a reservoir flow model, a geomechanical model, and a fracture model of the geomechanical reservoir system;

the system of partial differential are coupled through a fully-expanded Jacobian;

the solving of the system of partial differential equations comprises solving simultaneously in a single timestep the fully-expanded Jacobian based upon the received physical properties data;

the reservoir model and the geomechanical model are computed on the three-dimensional grid;

the fracture model is computed on the two-dimensional grid; and

the fracturing predictions model the geomechanical reservoir system for the timestep.