Bringing together reservoir simulation model, production towers and 4D seismic into the same visualization environment along with geological and petrophysical data. Data used with permission of owner.
Risks are inevitable with any hydrocarbon asset development, and while there is no way to completely eliminate risks, there are ways to reduce them and optimize asset production. One such mitigation strategy is through 4D seismic monitoring of a reservoir.
The acquisition of time-lapse seismic data allows geoscientists and engineers to visualize the reservoir in greater detail and also understand how the reservoir changes over time due to production, injection, compaction and other factors, allowing them to foresee potential challenges. This article discusses how the integration of 4D seismic data with the reservoir simulation model and production data can lead to enhanced reservoir understanding and better decision-making.
4D Seismic and Subsurface Data Integration
With complex reservoirs such as mature fields or deep water offshore fields, geophysicists and engineers can be overwhelmed with large volumes of data that may be difficult to digest and analyze without the right tools in place, leading to overlooked data that could have been critical to field development decisions. In deepwater development, the use of CoViz 4D—an integrated software solution—can be part of a permanent reservoir monitoring (PRM) system that can easily merge 2D, 3D and 4D (time-varying) data including well data (completions, logs, etc.), interpreted horizons, static and dynamic models, fluid production data and multiple seismic volumes.
Within a single platform, CoViz 4D can integrate multidisciplinary data regardless of format and make the data accessible to all members of an asset team. As the field develops over time, newly acquired seismic data and production data can be seamlessly integrated with the existing subsurface data to more easily perform history matching studies and forward modelling of 4D seismic responses.
With the integration of all available subsurface data, the asset team can achieve:
- consistent monitoring of fluid and pressure fluctuations
- enhanced analysis to strategize well-placement and well-positioning
- data organization that enhances the likelihood of finding bypassed reserves
The integrated visual and quantitative environment within CoViz 4D Provides extensive insight into reservoir conditions as they change over time. The ability to see these historical changes and use the information to perform forward modeling leads to a more complete understanding of current and future reservoir conditions. Better decisions can then be made resulting in money-saving strategies and enhanced exploitation efforts.
Seismic Forward Modeling: Sim2Seis
Another area where CoViz 4D excels is in its seismic forward modeling and seismic history matching workflows. The CoViz Sim2Seis workflow, an optional module to CoViz 4D, allows the geophysicist and reservoir engineer access to powerful and flexible synthetic seismic volume creation tools from directly within the data fusion framework. The workflow uses a reservoir simulation model as its starting point, and allows for rapid iterations with different input data and parameters.
The series of observed 3D seismic surveys can be visually and quantitatively compared to the resulting synthetic seismic volumes to assess if the reservoir simulation model gives a good match or if different fluid saturation scenarios need to be considered.
The Sim2Seis workflow includes the following steps:
- Calculating time-variant petroelastic attributes, bulk density and seismic velocity
- Convolving the petroelastic model with a seismic wavelet to compute the synthetic seismic response
- Quantitative and qualitative comparisons of the synthetic 4D seismic response with the measured seismic response to determine how the reservoir model must modified reflect the 4D conditions
Using the Sim2Seis workflow within the CoViz 4D environment allows geophysicists and engineers seamless access to tools for synthetic seismic creation and seismic history matching of reservoir models. Sim2Seis results are easily integrated with all of the field’s subsurface data to provide additional reservoir context and a robust QC environment. As field development continues, new 4D seismic volumes are readily integrated into both the CoViz visualization environment and Sim2Seis workflow to further inform the seismic history matching process and reservoir simulation modeling.
4D Seismic Monitoring with CoViz 4D
CoViz 4D provides a single platform for multidisciplinary asset teams to integrate and visualize all subsurface data, including data from 4D seismic monitoring studies, to better understand changing reservoir conditions over time. The ability to examine the reservoir’s history and monitor pressure and fluid fluctuations, for example, allows for more informed development decisions.
Using the CoViz Sim2Seis workflow within this same environment provides additional information about the conditions in the field and robustness of the reservoir simulation model. The resulting synthetic seismic response may indicate the need to adjust the reservoir model to match the observed seismic conditions.
With an integrated approach, the asset team has a more complete understanding of subsurface conditions and is better prepared to mitigate risk.
CoViz 4D, a data visualization analytics software from Dynamic Graphics, Inc., provides the necessary tools that help users craft viable strategies to monitor the status of reservoir shifts and dynamics. Contact our team today to learn more about 4D seismic monitoring and the use of Sim2Seis to gain better insight into reservoirs.
