In fractured reservoirs across China, Southeast Asia, the Middle East, South America, Canada, Russia and Europe, fields are being poorly swept, wells are encountering early water breakthrough, and oil is being lost. Two-thirds of the world’s proven reserves lie in areas with acknowledged fracture-affected recovery and in a large number of cases the issue is not being addressed. Fractured reservoir fields are often unique, there is no off-the-shelf solution.
But you can still model your reservoir and find a good solution. RMS Fracture software, a fully integrated module of RMS, helps both general and specialist users gain insight into their reservoir behavior. RMS Fracture is both fast and easy enough for fracture model creation and updating to become as routine as updating the facies model.
Fractures play an important role in understanding the flow behavior of many reservoirs. To appreciate the role of fractures we must be able to:
- Predict fracture density away from the well.
- Predict which fractures are likely to contribute to flow.
- Model dynamic properties of the fractures in a way that is consistent with observation.
RMS focuses on efficiently building effective fracture models based on:
- Conditioning models to well fracture data.
- Providing geologically reasonable extrapolation trends for well data.
- Using dynamic information to constrain the model based on interpreted well test permeability.
RMS Fracture Modeling Benefits
- Flexible, fast and interactive.
- Multiple scenarios and uncertainty assessment based on fracture model inputs.
- Create your fracture model on large geological grids for more accuracy.
- Condition permeabilities to real well data.
- Benefits from full integration with top-of-the-line geomodeling and upscaling tools and direct links to simulation packages.
- Can generate data for single-porosity or dual porosity models.
FAST AND ROBUST PERMEABILITY MAPPING
This modeling technique is based on direct inversion and produces effective permeability maps. Where well permeability data is available, it is possible to quickly reach a fracture permeability model, calibrated to real well permeability information. having a clear, confident understanding of fracture distribution and reliable extrapolation trends is an extremely fast and smooth route to a robust fracture permeability model. The straight-to-grid modeling functionality generates effective permeability maps.
- Based on the distribution of fractures in the reservoir.
- Direct export to single porosity reservoir simulators.
- Fast and directly calibrated to dynamic well data.
- Excellent performance times for large numbers of wells.
- The more wells, the better the results!
DISCRETE FRACTURE NETWORKS - DETAILED MODELING
While it is possible to go directly from trend modeling to matching effective permeability, it is often insightful to use discrete fracture networks (DFNs) to build a fracture model that is valid from a structural geological perspective. Lack of reliable well data may mean that a model must be constructed from core geological concepts, using aspects of the 3D model to constrain the input. For this, it is necessary to obtain greater control over the details of the fracture model. RMS Fracture can handle very large numbers of fractures with such speed that it can truly be said to model the field at the well scale.
DFNs model fractures explicitly. The distribution of fractures may be described by fracture density 3D parameters. These maps may be determined by a number of different methods, including proximity to fault, curvature, and stress models.
Different models are possible depending on fracture type or orientation, stress boundary conditions etc. It is also possible to generate density and orientation constraints based and conditioned to wells or any outcrops observations. RMS can thus be used to generate models of areas where data are very limited or poorly interpretable.
The DFN is constructed to:
- Strictly follow the trends dictated by the indicator maps (stress, curvature, etc).
- Allow for individual modeling of specific fracture types and their truncation rules.
- Respects well observations, to azimuth data, and to rock parameters or layering.
The model can be interactively modified to provide maximum quality control on the final product.
INTEGRAL STRESS CALCULATOR
RMS Fracture contains its own stress modeler, taking an applied stress field and using elastic dislocation modeling to map the stress distribution in the reservoir volume. This gives a snapshot of the stress field which created the fracturing. Parameters derived from the stress tensor are returned to RMS as a series of grid properties which are immediately available for use in controlling local variations in orientation and distribution of fractures in the model.
The stress modeling interface has been streamlined for ease of use. Geomechanical constants can be adjusted where necessary to accommodate the impact of significant changes in rock behavior. RMS Fracture can therefore model fracture networks developed from either a causal or descriptive approach, allowing maximum flexibility in data utilization.