The structure of a field is often one of the most critical components of the reservoir model and can account for the greatest uncertainty in terms of in-place reserves. Combine this with the time it can take to build accurate models and the limitations in many approaches, and you have a substantial drain on the asset team and a significant source of uncertainty in the field model. The RMS™ Structure Modeling tool provides one of the most powerful productivity and accuracy enhancement solutions currently available in reservoir management or field development planning.
Structure Modeling Benefits
- RMS structure modeling can handle thousands of faults, making the level of structural complexity modeled now a user choice rather than a software limitation.
- Cutting edge technology ensures geologically accurate grids that are also simulation friendly and support accurate production predictions.
- Combined with workflow management tools, the model update process is fast and streamlined, ensuring timely decisions and a much higher ROI on data acquisition and interpretation time.
- Advanced fluid contact handling and model gridding increase simulation result reliability
Structure Modeling Features
RMS’s structure modeling solution provides tools and workflows for going from data to grid in a minimum number of steps without compromising the structural integrity of the model. The integrated system helps users achieve maximum reservoir performance and better decisions through quick and accurate characterization of their reservoirs.
The tools and technology for fault and horizon modeling can reduce the time required to build a structural framework from weeks to days. This frees users to either build more scenarios to improve the level of uncertainty understanding of the reservoir, or to work on other projects, resulting in significantly increased productivity. When combined with the workflow management tools, the model update process is fast and streamlined. This ensures timely decisions, yielding a much higher ROI on data acquisition and interpretation time. Models can also be updated in real time as part of RMS’s geosteering workflows.
RMS structure modeling can handle thousands of faults, allowing extremely complicated structural models without a need for over-simplification. The level of structural complexity modeled is now a user choice rather than a software limitation. Fault surfaces closely honor the input data while users retain control over the details. Fault surfaces may die out laterally or in depth, and can be truncated by unconformity surfaces. Any type of antithetic and synthetic fault intersections can be modeled, including Y faults, Lambda faults, and K faults, as well as crossing conjugate or X faults. Fault truncations can be a combination of automatic and interactively defined in 3D. Finally, a fault QC tool guides the user through checking fault surface shape, fault/fault intersections, and truncations. This tool is indispensable for ensuring high-quality models.
Reaching the Far Horizon
Horizon surfaces can be generated directly from interpreted seismic data or calculated using well and thickness data. Truncation by unconformities is handled precisely and accurately. The entire stratigraphic modeling process can be done in a single step or as a nested process. Integrated isochore modeling creates thickness surfaces (isochores) from input data and a reference structural model. Isochores may be calculated as true vertical thickness or true stratigraphic thickness. Multivalued intrusion features such as salt domes are easily modeled and included not only in the structural framework, but also in the grid. RMS horizon modeling can utilize zone logs to control horizon surfaces and ensure that the structural framework honors all the information from horizontal wells, without the addition of pseudo data. As with fault modeling, there are QC tools to ensure the highest quality result.
Modeling Fluid Fill
Advanced fluid contact handling resolves the issues arising from areas with varying contact levels. Different regions can be defined based on the structure model, and these are used to map different contacts in separate regions and zones. These can be mapped accurately using structural maps or cross sections.
Improved Reservoir Simulation
3D grid building, designed to work with structural framework building, ensures that as much of the structural complexity as possible is incorporated into the grid. Any set or subset of faults may be treated as pillar or stair-stepped faults. The unique methodology used for stair-stepping reverse faults eliminates the shadow zone problems often seen in corner point grids and maintains layer connections across the fault blocks. Grid layering can be proportional, conformal, or a combination of the two, reducing the number of inactive cells when zones are truncated by unconformities. Boundaries between zones may be regularized, eliminating wedge-shaped cells and improving flow simulation. Geologically accurate grid layering is generated using extrapolated interpretations of eroded stratigraphy to control layering under unconformities. Flexible control line tools aid the design of simulation grids. The results are grids which are not only more geologically accurate, and therefore better for reservoir modeling, but also simulation friendly and suitable for accurate predictions of production.
|Left: Gas and oil areas on a surface in the horizon model. Right: Facies display in the grid model generated from the structure model shown on the left.