Integrated modeling and simulation of subterranean region and well performance

Abstract

A system includes a modeling platform that includes a software program for analyzing geology and simulating downhole processes in response to a downhole operation. The platform is configured to execute a simulation workflow that includes receiving information related to the subterranean region and a downhole system, generating a base geological model of the subterranean region, constructing a calibrated static fracture model of a fracture network in the subterranean region, and generating a combined fracture model by combining the base geological model and the static fracture model with a dynamic fracture model, where the combining includes directly outputting information from the base geological model and the static fracture model to a processing module in the modeling platform. The workflow also includes simulating a response of the fracture network to a change in a downhole condition, and determining a set of operational parameters of a downhole operation based on the simulating.

Description

INTEGRATED MODELING AND SIMULATION OF SUBTERRANEAN REGIONAND WELL PERFORMANCECROSS REFERENCE TO RELATED APPLICATIONSThis application claims the benefit of U.S. Application No. 63 / 609521, filed on December 13, 2023, which is incorporated herein by reference in its entirety.BACKGROUND

[0001] Some forms of energy production involve a number of diverse activities from various engineering fields to be performed in a borehole penetrating a subterranean region. For example, various drilling, exploration, stimulation and production processes are performed in the context of producing hydrocarbons. Other activities include carbon sequestration and geothermal energy recovery.

[0002] Fractures in a subterranean region (e.g., natural and induced fractures) can have a significant effect on the flow of fluids and thermal energy in a formation or other subterranean region. Understanding the behavior of fractures and fracture networks is important part of designing and performing subterranean operations.SUMMARY

[0003] An embodiment of a system includes a modeling platform that includes a software program for analyzing geology and simulating downhole processes in response to a downhole operation, the downhole processes related to thermal flow and fluid flow through a fracture network in a subterranean region, the platform configured to execute a simulation workflow. The workflow includes receiving information related to the subterranean region and a downhole system, generating a base geological model of the subterranean region, constructing a calibrated static fracture model of the fracture network in the subterranean region, and generating a combined fracture model by combining the base geological model and the static fracture model with a dynamic fracture model, where the combining includes directly outputting information from the base geological model and the static fracture model to a processing module in the modeling platform. The workflow also includes simulating a response of the fracture network to a change in a downhole condition based on the combined fracture model, and determining a set of operational parameters of a downhole operation based on the simulating.

[0004] An embodiment of a method includes providing information related to a subterranean region and a downhole system to a modeling platform that including a software program for analyzing geology and simulating downhole processes in response to a downhole operation, the downhole processes related to thermal flow and fluid flow through a fracture network in a subterranean region, and executing a simulation workflow by the platform. The workflow includes generating a base geological model of the subterranean region, constructing a calibrated static fracture model of the fracture network in the subterranean region, and generating a combined fracture model by combining the base geological model and the static fracture model with a dynamic fracture model, where the combining includes directly outputting information from the base geological model and the static fracture model to a processing module in the modeling platform. The workflow also includes simulating a response of the fracture network to a change in a downhole condition based on the combined fracture model, and determining a set of operational parameters of a downhole operation based on the simulating.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

[0006] Figure 1 depicts an embodiment of a downhole system for performing stimulation and geothermal energy recovery operations;

[0007] Figure 2 depicts an embodiment of a processing system;

[0008] Figure 3 depicts a processing system including processing modules for performing functions including modeling, simulation and optimization of downhole components and environments; and

[0009] Figure 4 depicts a processing environment that includes a plurality of models, as well as aspects of a workflow for simulating a downhole environment and responses of the downhole environment to downhole operations.DETAILED DESCRIPTION

[0010] Systems and methods are described herein that provide for simulation, modeling and evaluation of a subterranean region. An embodiment of a processing system includes a modeling platform that includes an integrated suite of programs and / or processing modules for modeling and simulation of various aspects of a downhole environment. In an embodiment, the subterranean region is a fractured region having a network of one or morefractures or faults with rock and other subterranean materials. The systems and methods are applicable to a variety of energy industry systems, such as geothermal systems, oil and gas production wells and injection wells.

[0011] The systems and methods described herein provide for improved workflows that integrates geological and fracture network models with dynamic fracture modeling in a single modeling workflow. The workflow allows for modeling natural and induced fracture networks considering both static and dynamic properties of such networks.

[0012] The workflow includes generating a base model by combining a geological model with a discrete fracture network (DFN) model, and a dynamic fracture model (DFM) to simulate fracture propagation. The resulting combined model is used for simulation of fracture behavior in response to various operating scenarios related to a downhole operation. The workflow may also include simulating thermal and fluid flow based on a reservoir model that is incorporated with the combined model.

[0013] Embodiments provide for effective modeling that comprehensively simulates fracture network behavior, fluid flow and thermal flow for a planned operation. Embodiments increase the effectiveness and productivity of various subterranean or downhole operations, including geothermal operations.

[0014] In addition, the embodiments combine static fracture models, dynamic fracture models and flow models into a single platform that both improves efficiency (in terms of time and processing power), and allows for integration of data and analyses from a variety of different expertises. In addition, models can be integrated without significant loss of resolution, and embodiments can avoid the loss of fidelity that typically occurs when using different platforms.

[0015] For example, embodiments help to increase the productivity of geothermal recovery systems (as well as other types of downhole systems), and reduce project risk by including dynamic fracture modeling in a design lifecycle. The combined modeling described herein accurately provides dynamics information to engineers and others involved in designing operations, so that the behavior of a fracture network can be reliably assessed. This assessment improves a number of aspects of project design, such as drilling services, drill bit selection, pressure pumping, chemical intervention, artificial lift and others.

[0016] Figure 1 depicts an embodiment of a downhole system 10 configured for geothermal energy extraction. It is noted that embodiments described herein are not limited to geothermal applications, and may be used in conjunction with various downhole and / orenergy production operations. Examples of such operations include drilling, stimulation, exploration, production and others.

[0017] In an embodiment, the system includes a first borehole 12 and a second borehole 14 extending into a subterranean region 16. The subterranean region may be a geologically active formation or any subterranean region or formation having a temperature sufficient to produce a usable amount of heat energy.

[0018] The first borehole 12, also referred to as an injector well 12, is connected to surface equipment configured to inject water therein and includes a length extending generally horizontally in the subterranean region. The second borehole 14, also referred to as a producer well 14, includes a length at the same or a similar depth that also extends generally horizontally. It is noted that the depths, lengths and paths defined by the injector well 12 and the producer well 14 are not limited to the specific configurations described herein; the wells can be at any suitable depth, have any suitable direction (e.g., vertical, horizontal or deviated) and be positioned relative to each other in any manner such that injected water can flow through the subterranean region 16 between the wells.

[0019] For production of energy, cold fluid is injected into the injector well 12 via surface equipment 18 (e.g., a drill rig) under pressure and migrates through the subterranean region 16 into the producer well 14, from which the fluid is brought to the surface at surface equipment 20. “Cold” as described herein refers to a temperature below the subterranean region temperature and below the temperature of produced water. “Hot” as described herein refers to water that has been heated to a temperature above the temperature of the injected water. For example, it may be desired that the hot water have a temperature above the water’s boiling point at the surface. In this example, steam can be generated that can be transmitted to a turbine or transmitted for another use. It is noted that, although the injected fluid is described herein as water, the injected fluid may be any suitable liquid.

[0020] Any suitable drive mechanism can be used to facilitate production of the heated fluid. Examples of such mechanisms include geologic pressure, injector pump pressure, producer pump pressure or a combination thereof. For example, as shown in Figure 1, the injector surface equipment 18 includes a fluid control system 22 including one or more pumps in fluid communication with a fluid source 24. Alternatively, or in addition, the producer surface equipment 20 includes a pumping system 26 and piping or other mechanism to transmit heated water and / or steam to a desired facility 28, such as an electric power plant or heating system. A lift mechanism such as an Electric Submersible Pump (ESP) 30 may be disposed downhole as desired to facilitate circulation of fluid.

[0021] The system 10 may include one or more processing devices configured to perform various functions. For example, a controller or other processing unit 32 is in communication with the surface equipment 18 and / or the surface equipment 20. The processing device or devices are not so limited. For example, processing units may be disposed downhole (e.g., in the injector well). The processing unit 32 includes components for performing functions such as controlling fluid flow through the system 10, controlling downhole components, monitoring components, transmitting and receiving data, processing measurement data and / or monitoring operations.

[0022] The system 10 also includes one or more flow control devices 40 disposed at the injector well 12 and / or the producer well 14. The flow control devices 40 are configured to control the flow rate of the fluid through the subterranean region in order to control the temperature of the fluid and / or to control the distribution of temperature of the fluid entering through multiple production zones. Examples of flow control devices include active inflow control devices (ICDs), passive flow control devices, screens, valves, sleeves and others. The system 10 may include a plurality of flow control devices 40 in each of the injector well 12 and the producer well 14 as shown. However, the system 10 is not so limited and can have any number of flow control devices 40 in the injector well 12 and / or the producer well 14.

[0023] For example, an injection string 42 is disposed in at least a horizontal section of the injector well 12, and a production string 44 is disposed in at least a horizontal section of the producer well 14. The injection string 42 includes a tubular that extends along at least the horizontal section, and a plurality of outflow ports 46. A flow control device 40 is disposed at or connected to each of the outflow ports 46.

[0024] As noted above, the producer and / or injector wells may be vertical, inclined, horizontal or a combination thereof. Thus, the embodiments are not limited to any particular well path or configuration, and the injection string 42 is not limited to being disposed in a horizontal section (the injection string 42 may be disposed at any desired location or section of a well or borehole). The producer and injector wells can have many configurations that can be selected or optimized using the techniques described herein.

[0025] The production string 44 includes a tubular that extends along at least the horizontal section, and a plurality of inflow ports 48. Each inflow port 48 provides an opening to establish fluid communication with the subterranean region 16.

[0026] Various tools and / or sensors may be incorporated in the system 10. One or more measurement tools can be deployed downhole for measuring parameters, properties or conditions of the borehole, formation and / or downhole components. Examples of sensorsinclude temperature sensors, pressure sensors, flow measurement sensors, porosity sensors (e.g., nuclear sensors or acoustic sensors), fluid property sensors and others.

[0027] For example, one or more sensors may be placed at suitable locations in the borehole 14 and / or the production string 12 to provide measurements or information relating to downhole parameters of interest. Exemplary sensors include temperature sensors, pressure sensors, flow measurement sensors, resistivity sensors, sensors that provide information about density, viscosity, water content or water cut, and chemical sensors. Density sensors may be fluid density measurements for fluid from each production zone and that of the combined fluid from two or more production zones. Resistivity sensors may provide measurements relating to the water content or the water cut of the fluid mixture received from each production zones. The temperature, pressure and flow sensors provide measurements for the pressure, temperature and flow rate of the fluid.

[0028] The system 10 of Figure 1 may be a conventional system that can be used in regions where there is sufficient access to hot brine (naturally occurring fluids that can flow through natural fractures).

[0029] In some regions, access to hot rock is achievable but there is insufficient permeability or fluid saturation. In such a region, the system 10 may be an unconventional system, which includes equipment for stimulating fractures and / or injection of fluids to facilitate recovery of thermal energy. Hydraulic treatments can be applied to increase permeability through shear displacements in natural fracture networks.

[0030] Figure 2 is a block diagram of an example of a computer system 50 that can be used to perform aspects of embodiments described herein. In this example, the system 50 is distributed data storage, processing and communication system.

[0031] The system 50 includes a plurality of processing devices or nodes 52. The nodes 52 each have computing components and capabilities, are connected by links 54, which may be wired or wireless. It is noted that one node 52 may perform all of the modeling and simulation functions described herein, or multiple nodes 52 may perform the functions in combination.

[0032] One or more of the nodes 52 may be connected via a network 56, such as the Internet or an internal network. Each node 52 is capable of independent processing, and includes suitable components such as a processor 58, memory 60 and input / output interface(s) 62. The memory 60 stores data and programs, such as input data from a user or other processors and programs. Examples of data include files storing modeling information.

[0033] In one embodiment, the memory 60 stores various processing or program modules 64 for performing aspects of embodiments described herein, which may be incorporated into a program suite. The nodes may be computing devices of varying size and capabilities such as server machines, desktop computers, laptops, tablets and other mobile devices.

[0034] In one embodiment, the system includes one or more data storage locations. For example, the system 50 includes a database 66. In one embodiment, one or more of the nodes 52 is a host that stores data and communicates with one or more nodes 52 as clients. For example, one or more of the processing devices 42 includes a server that acts as a host computer or host storage device and performs data management and data services functions.

[0035] A processing system, such as the surface processing unit 32, the system 50 and / or one or more processing devices 52, incorporates an integrated suite or system of processing modules or programs that provide various modeling, simulation and analysis services. The system provides methodologies and simulation and / or analysis tools for simulation and analysis of a subterranean environment.

[0036] Figure 3 depicts a topology of an embodiment of a modeling, simulation and design platform 80. The platform includes a number of processing modules configured to perform functions related to modeling a subterranean region and downhole system (e.g., geothermal system) and simulating responses of the subterranean region (e.g., fracture propagation) to downhole conditions.

[0037] The platform 80 enables downhole systems to be evaluated and designed, so as to improve or optimize the effectiveness of a downhole operation. For example, the platform 80 provides for effective and comprehensive evaluation of geothermal and / or other systems.

[0038] For example, the effectiveness of geothermal energy production is dependent on the behavior and response of fracture networks to changes in downhole conditions and operational parameters. The platform 80 can be used to simulate various behaviors and phenomena, such as fracture propagation, fluid flow and thermal dynamics due to changes in hydraulic, thermal and mechanical stresses induced by fluid injection and recovery. Other behaviors may include seismicity induced by hydraulic pressure during injection and extraction. The platform 80 can be used to simulate these and other behaviors.

[0039] A data acquisition module 82 acquires data from sensors in a geothermal system (or other downhole / surface system). In addition, the module 82 performs data interpretation and integration, or receives interpreted and / or integrated data related to variousoperations. Source data are collated and migrated from available one-dimensional (ID) and three-dimensional (3D) geological, geophysical, structural, geomechanical, microseismic, thermal, hydrological, and geochemical data. Such data can be collected from various sensors or in-field sampling and observations (e.g., one or more of the sensors discussed in conjunction with Figure 1).

[0040] Data from the acquisition module 82 is provided to a geological structural framework module 84. In an embodiment, the framework module 84 includes a three- dimensional geological model that functions as a base model. Additional models, including a model of a fracture network and / or a dynamic fracture model, are incorporated into or combined with the base model to generate a comprehensive model or simulation of a subterranean region and subsurface operation.

[0041] The structural framework module 84 generates and / or maintains a static model as the base model, which includes representations of geological and structural features, as well as geophysics and geochemistry characterizations.

[0042] A static fracture modeling module 86 constructs a static model of a fracture network. In an embodiment, the module 86 constructs a discrete fracture network (DFN) model based on fracture and fault information. The DFN model simulates the structure and geometry of a fracture network in a region (e.g., between the injector well and the producer well of Figure 1), as well as permeability and transmissivity characteristics. The static fracture modeling module 86 may also incorporate geomechanical modeling to couple the DFN model with geomechanics. Geomechanical modeling may be performed by a geomechanical modeling module 90 in the platform 80.

[0043] A dynamic fracture modeling module 88 receives a DFN model or DFN information, and simulates dynamic phenomena in the fracture network. The dynamic fracture modeling module 88 simulates, for example, fracture propagation and generation of new fractures (if applicable) in response to an operation, such as a stimulation operation and / or geothermal extraction operation. The module 88 may also incorporate microseismic simulations from, for example, a microseismic modeling module 92.

[0044] Outputs from the geomechanical modeling module 90, the static fracture modeling module 86 and / or the dynamic module 88 are applied to the base model to generate combined model of the subterranean region. The combined model can thus be generated using a single platform, and used for purposes including simulation of scenarios (e.g., geothermal operations having various operational parameters), evaluation of the effectivenessof geothermal and / or other operations, as well as well construction and plant design planning (shown as element 96)

[0045] The platform 80 may also include a reservoir simulation module 94 that simulates heat flow and fluid flow. The module 94 may generate a reservoir model, which is integrated with the combined model.

[0046] The platform 80 may be incorporated into an energy industry data storage, analysis and / or modeling software program suite. An example of such a program suite is the JewelSuiteIManalysis and modeling software by Baker Hughes Incorporated.

[0047] Figure 4 shows an example of a topology of the system 80, including various inputs and outputs. Figure 4 also shows aspects of a simulation workflow, which may correspond to a method of evaluating a subterranean region. It is noted that the method and workflow are not limited to the specific steps performed therein. For example, some steps may be omitted, and one or more of the steps may be performed in a different order than described herein in conjunction with Figure 4.

[0048] The workflow begins with entry of input data to the structural framework module 84. Examples of such data include geological, structural, geophysical, geomechanical, microseismic, thermal, hydrological, and geochemical data from various sources to generate a geological model and populate the structural geological model volume.

[0049] Structural data may include structural horizons, faults and natural fracture data, and stratigraphy. For example, the module 84 receives data that includes borehole trajectory information 100, such as descriptions of the trajectory of an existing system (e.g., the geothermal system of Figure 1) or planned system. The module 84 also receives formation measurement data 102 (e.g., downhole logging data and / or core data), seismic data 104 (e.g., from downhole seismic or acoustic measurements and / or survey data taken from the surface), and microseismic data 106.

[0050] The input data is integrated into a three-dimensional (3D) subsurface model or geological model 108, which is also referred to as a “base model.” The base model 108 is used as a basis for subsequent simulation and reservoir modeling tasks.

[0051] The base model 108 includes a geological model 110 that describes the geological structure of a region. The base model 108 may also include a geomechanical model 112 describing an initial state of a region. In an embodiment, the base model 108 is constructed by populating a model grid 114 with information including, for example, petrophysical properties, geomechanical properties, thermal properties, pore pressures, fluid properties and temperatures.

[0052] The workflow continues at the static fracture modeling module 86, which constructs a DFN model 116. Geomechanical information is used to generate a geomechanically coupled DFN model 118. The coupled DFN model 118 is constructed, for example, using fracture and fault data from the reservoir to inform deterministic and stochastic DFN realizations (i.e., based on randomly selected probability distributions) that are dynamically calibrated against available reservoir hydrological test (injectivity, tracer) data.

[0053] In an embodiment, the coupled DFN model 118 is generated by coupling with a geomechanical model 124 (e.g., a four-dimensional model having three spatial dimensions and a time dimension) from the geomechanical modeling module 90 in order to simulate responses of a modeled fracture network to stimulation. Stimulation typically involves simulating injection of fluid into the fracture network (e.g., via the injector well 12). Fracture network geometry, permeability and transmissivity may be computed if desired.

[0054] The DFN model 116 may be upscaled to generate an upscaled DFN model 120, and populate a model grid 122 with information from the DFN model 116 and the geomechanical model 124. One or more stimulation scenarios may be applied to the model 124, where each scenario includes operational parameters, such as fluid type, injection pressure and flow rate, duration of injection and others.

[0055] The DFM module 88 and the reservoir simulation module 94 are used to simulate fracture network behaviors, fluid flow and thermal dynamics in response to various hydraulic stimulation procedures developed for a target injection well (and / or other downhole operations). Each stimulation procedure, having distinct operational parameters (e.g., fluid type, pump pressure, etc.), may be referred to as a scenario.

[0056] For example, for each scenario, the DFM module 88 constructs a dynamic fracture model (DFM), which includes a model 126 of hydraulic fracture propagation through intact rock and naturally fractured reservoirs via the stochastically generated DFNs.

[0057] The model 126 simulates fully coupled thermo-hydro-mechanical fracture propagation to account for the effects of temperature on stresses on the rock in the subterranean region, and effects of temperature on fluid properties. The model 126 also simulates fracture network permeability and its effects on the propagation of induced fractures and fluid leak-off.

[0058] The dynamic fracture model may include a model 128 that simulates microseismic events and locations, including parameters and mechanisms of microseismic events. For example, the model 128 simulates nucleation and propagation of elastic wavesfrom microseismic events (both wet and dry) based on material properties and changes in the physical state, including calculation of source locations, mode and orientation of fracture dynamics, and other seismic parameters.

[0059] In an embodiment, the dynamic fracture model is constructed by receiving information directly from the modules 84 and 86. Information includes geological properties (e.g., rock type, porosity, permeability, etc.) and fracture properties (e.g., fracture geometries, a fracture network description, etc.). The dynamic fracture module 88 receives information “directly,” in that the information is provided within the platform 80 without the need to migrate any data from other platforms or other programs.

[0060] A range of hydraulic stimulation plans for the resource engineering may be modeled to provide design scenarios that investigate the engineering sensitivities, provide for target heat flow optimization, and plan for field contingencies to reduce project risks. The results of these models may be iterated to calculate heat flow and energy output.

[0061] Outputs from the module 88 include, for example, stress information (e.g., in situ stress field), formation or rock mechanics, reservoir properties, DFN properties and / or options or available ranges for pressure pumping and available fluid types. These outputs, in combination with stimulation parameters for a given scenario (element 130) and results of the simulation (element 132), may be provided to the module 84 to generate combined model.

[0062] For example, upscaled fracture geometry and description of the fracture network from the static fracture modeling module 86 are input to the grid 114, so as to combine the geological model 110 and the coupled DFN 118. In addition, outputs from the module 88 are used to populate the grid 114.

[0063] The upscaled reservoir volume grid and properties, in an embodiment, are migrated to a reservoir simulation model 134 and the reservoir fluid properties are verified and added to the model. Local grid refinement (LGR) can be used to define grid properties around stimulated areas.

[0064] The reservoir model 134 may be used to optimize operation strategy to maximize energy output over a specified number of years. To understand the main drivers toward project success, sensitivity analysis can be utilized to test different injection and production scenarios. The reservoir model 134, the base model 108 can be updated once operational history data is available in the future.

[0065] The various models and the reservoir model 134 may be used to test scenarios for a given operation, and may also be used to forecast future scenarios with added newdevelopment options, such as new wells, increased injection or drawdown, or alternate completion strategies.

[0066] Reservoir modeling deliverables include optimized operational strategy for reservoir enthalpy calculations over a specified number of years for various injection volume scenarios, energy output over a specified number of years, and estimated pressure decline rates over a specified number of years. Other deliverables include summaries of sensitivity runs, data for use in financial and business-model assessment, and input specifications for optimization of surface plant equipment.

[0067] Set forth below are some embodiments of the foregoing disclosure:

[0068] Embodiment 1: A system comprising: a modeling platform that includes a software program for analyzing geology and simulating downhole processes in response to a downhole operation, the downhole processes related to thermal flow and fluid flow through a fracture network in a subterranean region, the platform configured to execute a simulation workflow including: receiving information related to the subterranean region and a downhole system; generating a base geological model of the subterranean region; constructing a calibrated static fracture model of the fracture network in the subterranean region; generating a combined fracture model by combining the base geological model and the static fracture model with a dynamic fracture model, wherein the combining includes directly outputting information from the base geological model and the static fracture model to a processing module in the modeling platform; simulating a response of the fracture network to a change in a downhole condition based on the combined fracture model; and determining a set of operational parameters of a downhole operation based on the simulating.

[0069] Embodiment 2: The system as in any prior embodiment, wherein the platform is configured to provide the set of operational parameters and the simulated response to a reservoir simulator, the workflow including simulating fluid flow and heat flow through the subterranean region based on the reservoir simulator.

[0070] Embodiment 3: The system as in any prior embodiment, wherein the static fracture model includes a discrete fracture network (DFN) model.

[0071] Embodiment 4: The system as in any prior embodiment, wherein constructing the static fracture model includes upscaling the DFN model, and integrating the upscaled static model with a geomechanical model to generate a coupled fracture model.

[0072] Embodiment 5: The system as in any prior embodiment, wherein simulating the response includes applying a plurality of operational scenarios to the combined fracturemodel, each operational scenario associated with a set of operational parameters, and selecting an operational scenario based on the applying.

[0007] Embodiment 6: The system as in any prior embodiment, wherein the downhole operation includes injection of a fluid into a borehole in the subterranean region, and simulating the response includes simulating fracture propagation and microseismic phenomena in response to the injection.

[0074] Embodiment 7: The system as in any prior embodiment, wherein the base geological model is constructed in a multi-dimensional model grid, and the combining includes populating the model grid with outputs from the static fracture model and the dynamic fracture model.

[0075] Embodiment 8: The system as in any prior embodiment, wherein the platform is configured to receive historical data related to one or more previously performed downhole operations, update the combined model based on the historical data, and forecast future scenarios.

[0076] Embodiment 9: The system as in any prior embodiment, further comprising a processing device configured to control the downhole operation based on the set of operational parameters.

[0077] Embodiment 10: The system as in any prior embodiment, wherein the downhole operation is a geothermal energy recovery operation.

[0078] Embodiment 11: A method comprising: providing information related to a subterranean region and a downhole system to a modeling platform that including a software program for analyzing geology and simulating downhole processes in response to a downhole operation, the downhole processes related to thermal flow and fluid flow through a fracture network in a subterranean region; and executing a simulation workflow by the platform, the workflow including: generating a base geological model of the subterranean region; constructing a calibrated static fracture model of the fracture network in the subterranean region; generating a combined fracture model by combining the base geological model and the static fracture model with a dynamic fracture model, wherein the combining includes directly outputting information from the base geological model and the static fracture model to a processing module in the modeling platform; simulating a response of the fracture network to a change in a downhole condition based on the combined fracture model; and determining a set of operational parameters of a downhole operation based on the simulating.

[0079] Embodiment 12: The method as in any prior embodiment, wherein the platform is configured to provide the set of operational parameters and the simulatedresponse to a reservoir simulator, the workflow including simulating fluid flow and heat flow through the subterranean region based on the reservoir simulator.

[0080] Embodiment 13: The method as in any prior embodiment, wherein the static fracture model includes a discrete fracture network (DFN) model.

[0081] Embodiment 14: The method as in any prior embodiment, wherein constructing the static fracture model includes upscaling the DFN model, and integrating the upscaled static model with a geomechanical model to generate a coupled fracture model.

[0082] Embodiment 15: The method as in any prior embodiment, wherein simulating the response includes applying a plurality of operational scenarios to the combined fracture model, each operational scenario associated with a set of operational parameters, and selecting an operational scenario based on the applying.

[0083] Embodiment 16: The method as in any prior embodiment, wherein the downhole operation includes injection of a fluid into a borehole in the subterranean region, and simulating the response includes simulating fracture propagation and microseismic phenomena in response to the injection.

[0084] Embodiment 17: The method as in any prior embodiment, wherein the base geological model is constructed in a multi-dimensional model grid, and the combining includes populating the model grid with outputs from the static fracture model and the dynamic fracture model.

[0085] Embodiment 18: The method as in any prior embodiment, wherein the platform is configured to receive historical data related to one or more previously performed downhole operations, update the combined model based on the historical data, and forecast future scenarios.

[0086] Embodiment 19: The method as in any prior embodiment, further comprising controlling the downhole operation based on the set of operational parameters.

[0087] Embodiment 20: The method as in any prior embodiment, wherein the downhole operation is a geothermal energy recovery operation.

[0088] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particularquantity based upon the equipment available at the time of filing the application. For example, “about” and / or “substantially” and / or “generally” can include a range of ± 8% of a given value.

[0089] The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a borehole, and I or equipment in the borehole, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

[0090] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.

Claims

CLAIMSWhat is claimed is:

1. A system (32,50,52) characterized by: a modeling platform (80) that includes a software program for analyzing geology and simulating downhole processes in response to a downhole operation, the downhole processes related to thermal flow and fluid flow through a fracture network in a subterranean region (16), the modeling platform (80) configured to execute a simulation workflow including: receiving information related to the subterranean region (16) and a downhole system (10); generating a base geological model (108) of the subterranean region (16); constructing a calibrated static fracture model (116) of the fracture network in the subterranean region (16); generating a combined fracture model by combining the base geological model (108) and the static fracture model (116) with a dynamic fracture model (126,128), wherein the combining includes directly outputting information from the base geological model (108) and the static fracture model (116) to a processing module in the modeling platform; simulating a response of the fracture network to a change in a downhole condition based on the combined fracture model; and determining a set of operational parameters of a downhole operation based on the simulating.

2. The system (32,50,52) of claim 1, wherein the modeling platform (80) is configured to provide the set of operational parameters and the simulated response to a reservoir simulator (94), the workflow including simulating fluid flow and heat flow through the subterranean region (16) based on the reservoir simulator (94).

3. The system (32,50,52) of claim 1, wherein the static fracture model (116) includes a discrete fracture network (DFN) model.

4. The system (32,50,52) of claim 1, wherein constructing the static fracture model (116) includes upscaling the DFN model, and integrating the upscaled static model (120) with a geomechanical model (112) to generate a coupled fracture model (118).

5. The system (32,50,52) of claim 4, wherein simulating the response includes applying a plurality of operational scenarios to the combined fracture model, each operational scenario associated with a set of operational parameters, and selecting an operational scenario based on the applying.

6. The system (32,50,52) of claim 5, wherein the downhole operation includes injection of a fluid into a borehole in the subterranean region, and simulating the response includes simulating fracture propagation and microseismic phenomena in response to the injection.

7. The system (32,50,52) of claim 1, wherein the base geological model (108) is constructed in a multi-dimensional model grid (114), and the combining includes populating the model grid (114) with outputs from the static fracture model (116) and the dynamic fracture model (126,128).

8. The system (32,50,52) of claim 1, wherein the modeling platform (80) is configured to receive historical data related to one or more previously performed downhole operations, update the combined model based on the historical data, and forecast future scenarios.

9. The system (32,50,52) of claim 1, further comprising a processing device (32) configured to control the downhole operation based on the set of operational parameters.

10. The system (32,50,52) of claim 1, wherein the downhole operation is a geothermal energy recovery operation.

11. A method characterized by: providing information related to a subterranean region (16) and a downhole system to a modeling platform (80) that including a software program for analyzing geology and simulating downhole processes in response to a downhole operation, the downhole processes related to thermal flow and fluid flow through a fracture network in the subterranean region (16); and executing a simulation workflow by the modeling platform (80), the workflow including: generating a base geological model (108) of the subterranean region (16); constructing a calibrated static fracture model (116) of the fracture network in the subterranean region; generating a combined fracture model by combining the base geological model (108) and the static fracture model (116) with a dynamic fracture model (126,128), wherein the combining includes directly outputting information from the base geological model (108) and the static fracture model (116) to a processing module in the modeling platform (80);simulating a response of the fracture network to a change in a downhole condition based on the combined fracture model; and determining a set of operational parameters of a downhole operation based on the simulating.

12. The method of claim 11, wherein the static fracture model (116) includes a discrete fracture network (DFN) model, and constructing the static fracture model (116) includes upscaling the DFN model, and integrating the upscaled static model (120) with a geomechanical model (112) to generate a coupled fracture model (118).

13. The method of claim 12, wherein simulating the response includes applying a plurality of operational scenarios to the combined fracture model, each operational scenario associated with a set of operational parameters, and selecting an operational scenario based on the applying.

14. The method of claim 13, wherein the downhole operation includes injection of a fluid into a borehole in the subterranean region, and simulating the response includes simulating fracture propagation and microseismic phenomena in response to the injection.

15. The method of claim 11, wherein the base geological model (108) is constructed in a multi-dimensional model grid (114), and the combining includes populating the model grid (114) with outputs from the static fracture model and the dynamic fracture model (126,128).

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