The characteristics of a hydrocarbon reservoir are dynamic due to the petrophysical changes induced by production activities. Understanding these changes is essential in monitoring subsurface behavior and hence for optimizing recovery. Time-lapse seismic reservoir monitoring is one way to minimize uncertainty and capture a more complete picture.
Integrating time-variant data with seismic data allows a comprehensive analysis of the reservoir response over the period of exploration, development, and production. Asset developers and planners can rely upon this dynamic picture and subsequent analysis to make optimal recovery decisions.
Understanding Time-Lapse Seismic Reservoir Monitoring
Traditional 2D and 3D visualization are successful at creating images and models that represent the geophysical characteristics of the reservoir. However, these integrations leave a risk of uncertainty if they come without the ability to track the changes in the reservoir over time. A full 4D analysis, on the other hand (which includes 3D seismic time-lapse data), is able to monitor the variation in reservoir properties over a period of time. With seismic time-lapse reservoir monitoring, geophysicists and reservoir engineers can:
- Observe the change in rock elastic properties which are likely due to production activities.
- Keep track of micro-seismic events over time and analyze their effect on production.
- Monitor faults, fractures, and their effect on fluid migration and saturation over time within the reservoir.
- Perform history matching by comparing time-lapse seismic data with existing models and production data to ensure accuracy of the 4D model.
- Monitor deformation in the subsurface that may result from hydrocarbon recovery or fluid injection.
- Monitor uncertainties due to potential well interference (where wells too close cause changes in production and injection).
To achieve this monitoring and analysis, however, requires a range of diverse data which includes various geologic models, well log and core data, production data, and reservoir attributes, in addition to the successive 3D seismic surveys. Integration of these data in a single geospatial and temporal environment enables a clear understanding of reservoir depletion for effective decision-making.
Integration for Extensive Analysis and Visualization
Time-lapse seismic reservoir monitoring utilizes a series of temporally spaced, geospatially equivalent 3D seismic surveys that are designed to show the variation of fluid and pressure changes in a reservoir due to production. Integrating various engineering and production data with a series of time-lapse seismic models allows efficient tracking of hydrocarbons during the entirety of the development and production phase. Visualizing with advanced technology such as CoViz 4D enables engineers and geoscientists to see the current state of the reservoir by monitoring the changes resulting from hydrocarbon exploitation in the characteristics of the reservoir.
CoViz 4D for Time-Lapse Seismic Reservoir Monitoring
CoViz 4D is uniquely suited to this task and can effectively facilitate integration and visualization of all data involved. CoViz 4D allows:
- Integration of large volumes of diverse data
- Present temporal data using time steps for reservoir simulation grid, well status, or production data
- Visualize one or more seismic volumes at the same time
- Sampling of 4D seismic data into the reservoir simulation grid
- Perform volume differencing between time steps in a single operation
- Advanced quantitative operations on seismic volumes and attributes
CoViz 4D allows for visualization of all the data, models, and grids in a comprehensive viewing environment, making it possible to analyze the reservoir condition. With accurate and fast analysis, asset teams are certain to have a better understanding which allows them to focus on investigating risk reduction opportunities for maximizing recovery and economic gains.