When it comes to hydrocarbon exploration, risks are inevitable; there’s no way to completely eliminate risks but there are ways to reduce them and optimize asset production. One such mitigation strategy is 4D seismic monitoring of reservoir change.
The ability to acquire time-lapse seismic data allows engineers to visualize the reservoir in greater detail and also understand how the reservoir changes over time, allowing them to foresee potential challenges. This article will discuss how the integration of 4D seismic data, the reservoir simulation model, and production data can lead to better decision-making.
Precise 4D Monitoring Campaigns
For complex ventures such as mature fields or offshore fields, professionals may be overwhelmed with large volumes of data that may be difficult to digest and analyze without the right tools in place—thus spawning ambiguity and missing data that could have been useful during the decision-making phase. Consider deepwater developments, for example. The use of CoViz 4D—an integrated software solution—can be part of a permanent reservoir monitoring (PRM) system that can merge volumetric data, horizon data, and point data. Analysts can derive important information from the 4D seismic data, including subsurface datasets that augment the quality of the seismic data.
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. Beforehand, an extensive quantitative merging of data was difficult when analyzing newly-arrived time-lapse seismic data like history matching or feasibility studies such as forward modelling of 4D seismic responses. With CoViz 4D, however, users can take the 4D seismic data and include it with other subsurface time-variant data in the form of fluid rates, completion locations, well logs, and geologic models.
With the inclusion of subsurface data, analysts 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
An integrated regimen provides extensive insight into reservoir conditions on a temporal level. The ability to add temporal changes of the reservoir into a central data platform alerts users of obstacles and money-saving strategies that can enhance exploration efforts.
Synthetic Seismic Comparisons
Another area where CoViz 4D’s capabilities are helpful is in its seismic history matching workflow via the available CoViz Sim2Seis modules—an option to CoViz 4D. The CoViz Sim2Seis workflow allows the reservoir engineer and geophysicist access to powerful and flexible synthetic seismic volume creation tools from directly within the data fusion framework inherent to the software, resulting in better, faster seismic history matching, and 4D seismic feasibility studies. When it comes to 3D/4D features, this visual system can assess reservoir variations in a succession of 3D/4D surveys. Further, professionals can choose different simulation models, where analysts use the best one that matches field conditions, giving teams more leeway in further refining the model to their liking.
The Sim2Seis module provides an evolving analysis through seismic data stemming from simulation models. The succession of 3D seismic surveys can be compared to the output of the synthetic seismic data to assess if the reservoir simulation models match on-the-ground production, including shifting reservoir dynamics.
The following process can be conducted with regard to the comparison of synthetic and seismic responses:
- Calculating time-variant petroelastic attributes such as density and seismic velocity
- Monitoring shifting subsurface variables using the petroelastic model with the seismic wavelet for the forward modeling that includes the synthetic seismic response
- The quantitative and qualitative comparisons of artificial 4D seismic response and the measured seismic response to know how the reservoir model must be recalibrated spatially and temporally to reflect the 4D conditions
The Sim2Seis workflow allows geophysicists and engineers to utilize synthetic creation tools with ease within a single network, giving them the chance to create 4D seismic feasibility studies and seismic history matches without additional training or formatting involved. Regardless of a person’s discipline, users can achieve a robust quantitative analytical system that entails quality comparisons and overlapping 3D/4D datasets that provide more context to subsurface dynamics—all of which can be fed into the simulation models to provide current information on a consistent basis.
4D Seismic Monitoring with CoViz 4D
With CoViz 4D’s Sim2Seis module and 4D seismic readiness, petroleum professionals can visualize subsurface conditions in a detailed capacity. The 4D benefit allows users to monitor pressure and fluid fluctuations and will help them position wells effectively. The creation of synthetic seismic response may indicate the need to adjust reservoir models to match the 4D seismic conditions.
The 4D benefit allows users to monitor pressure and fluid fluctuations and will help them position wells effectively.
Overall, the inclusion of 4D seismic monitoring will coalesce the streams of valuable information from complex reservoirs such as offshore reservoirs or mature fields, both of which can yield complex and large data volumes where the most pertinent bits of information can get lost in the shuffle. CoViz 4D makes data accessible to multidisciplinary teams, facilitating a cohesive analysis that can allow teams to adapt to changing circumstances and respond to a variety of challenges along the way. With a better team dynamic and organized data, the asset teams can mitigate risk and better understand subsurface reservoirs without losing valuable time and resources.