Managing fractured oil and gas reservoirs can be problematic, as conventional modeling approaches that treat rock as a continuous porous medium often lead to incorrect conclusions. Long-term development decisions should be based on hard data and rigorous analysis. FracMan® Reservoir Edition (FRED) provides powerful tools that help maximize the recovery from your fractured reservoir:
- Comprehensive data integration
- Static model development and validation
- Original Oil in place (OOIP) and field development planning
- Well planning and enhanced oil recovery (EOR) design
- Risk assesment
Analysis and Modeling: An Integrated Approach
Rather than rely on a single modelling paradigm, FracMan can integrate multiple data types and concepts into a comprehensive, consistent model. A variety of workflows are provided for:
- Fracture modeling based on seismic attributes, geomechanical data, and local features, such as folds, faults or stratigraphy
- Simulated well test matching for calibration of fracture aperture and permeability
- Upscaling fracture properties for full-field flow simulation
- Monte Carlo simulation and uncertainty analysis
Advanced Data Analysis
Essential information about fracturing comes from a variety of sources such as flow logs, image and wireline logs, outcrop studies and seismic surveys. FracMan can analyze this data to provide key information about:
- Orientation and size
- Fracture intensity and spacing
- Aperture and permeability
Realistic Fracture Modeling
Multiple formation process can be integrated to create a more complete characterization of the fracture network. Fracture geometry, intensity and permeability can be correlated to mechanical layering, structural deformation, seismic attributes, matrix properties, stress, train or curvature.
Assess Connectivity and Compartmentalization
Many reservoir engineering problems are geometric as well as hydraulic. By characterizing the connectivity of the fracture network critical aspects of flow and recoverability can be assessed:
- Compartmentalization and Tributary Drainage
- Sensitivity to factors such as size, orientation and stress
- Compartment volume and probably recovery
- Estimated Ultimate Recovery for existing and proposed wells
Well Planning for Exploration and Field Development
Once conductive fracture pathways have been identified, they can be exploited to maximize hydrocarbon recovery. FracMan’s connectivity analysis tools enhance your ability to:
- Minimize interference between production wells
- Avoid conductive pathways between injectors and producers
- Target the most productive reservoir features
- Estimate recovery from tributary drainage
Integrated Flow Simulation
FracMan’s integrated dual-porosity flow simulator uses a finite-element time-stepping approach which more accurately conforms to the geometry of the fracture network. This solver can be used to validate the model and calibrate fracture properties against actual well test data.
Upscaling for both Flow and Geomechanics Simulation
FRED computes equivalent fracture porosity, permeability,and shape factor in a few simple steps, and computations run in parallel on multiprocessor workstations and multi-core CPU architectures. Equivalent permeabilities are computed as full tensors, which reflect the directionality of flow in each grid cell. When you’re ready for full-field flow simulation, upscaled fracture properties can be easily exported to leading reservoir simulators.
Monte Carlo Simulation and Risk/Uncertainty Assesment
Sound reservoir management decisions rely upon accurately quantifying uncertainty. Maximize the probability of success by analyzing multiple realizations of your stochastic model. FRED can compute statistical assessments of key aspects of reservoir development, such as:
- Locating “sweet spots” to guide well planning
- Preventing short-circuits in EOR designs
- Estimating minimum, maximum and expected recovery
The properties of reservoirs dominated by fracture flow are frequently complex. Irregular fracture network geometries yield scale dependent and anisotropic behavior which is not observable in conventional reservoirs. Hydraulic response of a reservoir is further complicated by hydraulic interaction between fractures and the surrounding porous matrix. Discrete fracture network (DFN) models, which are capable of simulating both processes, represent the core of our capabilities.
Fracture network models provide the means for quantifying hydraulic properties from measured fracture data obtained by the exploration geologist. Depending upon the scale of fracturing, fracture network models can be used to estimate hydraulic parameters for reservoir simulation, well test data analyses, or reservoir performance estimates. The network realization are stochastic, so they can be used to quantify variability in the results. The models incorporate flow within the porous matrix as well as the fracture network using either, 1) computationally efficient analytical, or 2) geometrically exact numerical approaches.
Determination of Average Well Production and Expected Variance
Well production within fractured reservoirs is generally highly variable since effective connectivity up of the well with the existing fracture system is uncertain. Since the fracture network models use a stochastic approach, the probability distribution of well production can be determined. Quantification of uncertainties in reservoir development cannot be provided by standard reservoir models.
Optimization of Well Spacing
Optimization of well spacing within fractured reservoirs can be greatly enhanced using fracture network models. Specifically the fractured reservoir model can be used to assess permeability scale effects associated with the probable length of connected fracture networks, the effective drainage radius and effect of fracture anisotropy on the shape of the drainage patterns.
Evaluation of Well Stimulation Techniques
Fractured network models can predict the effectiveness of well stimulation techniques. The models provide the means of determining how successfully the created hydraulic fractures, or multiple fracture stimulations, link up with existing fracture systems. The permeability and anisotropy scale effects of fractured reservoirs are particularly important here and cannot be assessed with standard porous media or dual porosity models.
Evaluation of Secondary Recovery Performance
Secondary recovery within fractured reservoirs is often problematic, particularly when the injection fluid surrounds and isolates matrix blocks prior to their complete desaturation. It is possible to improve the effectiveness of oil recovery using fracture network geometry. This approach more accurately models injection fluid fronts than conventional reservoir models.
Calculation of Reservoir Simulator Input
Stochastic continuum models can be used in conjunction with fracture network models to simulate highly fractured reservoirs. When used to simulate fractured reservoirs, the distribution of individual element properties is determined from network fracture models. See the information on reservoir simulator interfaces for more information.