Primary and secondary oil recovery methods can leave as much as 75% of the oil in the ground. For many long-established wells such as those in California, Oklahoma, Texas, and Mexico where much of the easy-to-produce oil has already been extracted, tertiary or enhanced oil recovery (EOR)—although expensive in comparison to primary and secondary recovery—is the only option to reach the remaining oil.
Regardless of the enhanced oil recovery method used—steam, chemical, or gas—the ability to monitor the effectiveness of the process is critical in maximizing recovery and minimizing costs. When reservoir teams have access to relevant data associated with reservoir characteristics and performance, they stand a much better chance of planning, implementing, and monitoring enhanced oil recovery activities.
A Tale of Two Wells
Consider an actual scenario where two adjacent wells with two teams working independently were initially baffled by the results of their EOR efforts. Both teams decided on CO2 injection wells. Team One’s result from CO2 injection was disappointing. Results were significantly below expected injection-to-production ratios. In contrast, Team Two’s results from CO2 injection far surpassed reasonable expectations.
Each well was modeled separately, and initially, each team had only their well data to evaluate when attempting to identify the reason for the problem or anomaly. However, with the aid of CoViz 4D, software that integrates and visualizes a wide variety of subsurface data associated with hydrocarbon assets, the two teams were able to combine their models and visualize the two wells together.
Integrated Data Reveals Reason for Enhanced Oil Recovery Anomaly
By integrating the various datasets that modeled each field, CoViz 4D enabled the teams to evaluate the two fields as a single entity, including locations of injection wells, well completions, geologic formations, CO2 injection volumes, and production data. With an integrated view of data, reservoir engineers were able to isolate the problem and identify the cause of the anomalous EOR results. A thief zone connecting the two wells allowed CO2 from the poorly performing well to migrate to the over-performing well. The ability to view the combined well data revealed the reason for the anomaly that otherwise would have eluded the teams acting independently.
Monitor Enhanced Oil Recovery Activities
While the above example solved a perplexing problem, CoViz 4D has even broader applicability in helping reservoir teams manage enhanced oil recovery activities. It can incorporate data from temperature observation (TO) wells to show the extent of the steam chest, allowing reservoir and production engineers to monitor the progress of their enhanced oil recovery methods.
CoViz 4D can also integrate time-series data associated with seismic studies, reservoir simulation grids, well status, or production data. By animating these data over time, reservoir engineers can more clearly understand the interdependencies of these factors and their effect on enhanced oil recovery results.
Visually explore recovery strategies and the interaction among wells.
Data Registry Facilitates Integration of Subsurface Data Sources
A data registry is one of the key components of CoViz 4D’s ability to integrate a wide range of data sources. Seismic studies, geologic models, reservoir simulations, well plans, and many other datasets produced by discipline-specific software from vendors like Schlumberger and Halliburton are easily added to the data registry via drag-and-drop. CoViz 4D automatically handles the various data formats and presents the data in a common viewing environment. Without needing to know where the data originated or how to use the specific software that created it, individual members of the reservoir team obtain a more detailed understanding of the reservoir performance and the factors that influence it.
CoViz 4D automatically handles the various data formats and presents the data in a common viewing environment.
CoViz 4D for EOR Feasibility, Implementation, and Monitoring
In the case of enhanced oil recovery, access to all the relevant data provides an unprecedented ability for reservoir teams to evaluate the feasibility of EOR, determine the best recovery method, and monitor results. Combining and visualizing a wide range of reservoir data enables reservoir teams to:
- Estimate reserves using the latest reservoir simulations to determine project feasibility.
- Determine which EOR method—thermal, gas, or chemical injection—is likely to deliver the best results.
- Evaluate the effectiveness of EOR methods, based on geological conditions, previously applied to wells with similar geologic and petrophysical characteristics.
- Monitor EOR sweep and displacement efficiency.
- Compare injection inputs against production outputs to determine when EOR methods are no longer delivering expected results.
For operators who have exhausted primary and secondary recovery methods, yet still have significant reserves, CoViz 4D can be an essential tool for optimizing the planning, implementation, and management of enhanced oil recovery activities.