There are two main classes of oil well production problems—mechanical and reservoir. In both classes, much of the same unstructured data can be used to diagnose and resolve the problem but it is the resolution processes that differ once the source of the problem is identified.
When resolving oil well production problems, engineers and geoscientists need a sound data integration regimen that provides a wider context into well functionality. Combining data is especially pertinent when aggregating the records of the problematic and functioning wells, helping engineers find the cause of mechanical issues and geoscientists address issues within the reservoir that can stymie operations.
Addressing Mechanical Problems
Mechanical problems are often first noticed in the daily production records and notes that the pumpers provide. Pumpers report to engineers in the office and will often provide their opinion as to the nature of a potential mechanical problem. The engineer then reviews the production data and recommends remediation or abandonment of the well to his team and management.
Problems can be very clearly mechanical; in this case, if the pre-problem production was sufficiently economical a workover such as removing scale or similar deposits from perforations and replacing pumps, broken sucker rods, or tubing with holes, and cleaning sand out of the well is undertaken. If a problem isn’t clear, the most likely mechanical issues are addressed because these are often the least expensive issues to resolve.
Common Mechanical Issue: Sand Production
One of the most difficult challenges of well production is keeping formation sand in place to avoid impeding well productivity, which is a harder challenge without organized data. The problem grows more complicated, as not all sand production is inherently problematic, and there are times when sand production on a continuous level is necessary.
On the other hand, analysts must also know when to address excess sand production. This issue can be resolved with the proper sand control strategies. To implement effective strategies, surface and subsurface data should be merged together for a complete view of reservoir conditions. The integration of these datasets allows users to:
- craft a sand control method based on surface and subsurface conditions
- implement proper operating procedures that mitigate sand production
- determine the economic consequences of sand control techniques and the impact on the campaign
With the ability to access and integrate all records from problematic and surrounding wells—and view them in one comprehensive environment—engineers can better assess the true cause of a mechanical issue. If mechanical remediation isn’t effective then the problem likely lies in the reservoir.
Mitigating Reservoir Problems
Reservoir problems are more complex issues and often require a review of all well and reservoir data to identify the nature of the problem. The multidisciplinary data usually first indicates there is a production issue—similarly to when there is a mechanical problem. If the pumper doesn’t see a likely mechanical issue, team members review their information to help identify potential well/reservoir issues.
Team members need to be able to quickly visualize all data, technical interpretations, and models (engineering, geoscience, and petrophysical) and cross-correlate to help understand the problematic well in relation to other surrounding wells and the reservoir. Once a potential reservoir issue is identified, remediation is undertaken if it is an economically viable solution.
Remediation can take many forms including chemical cleaning of the wellbore, reperforation, and re-fracking. Because these operations can be costly, it is important that asset teams are able to quickly and accurately identify the issue and a solution that will most likely fix the problem. This can potentially save them from having to expend resources on additional re-completion attempts if the problem is initially misdiagnosed.
Common Reservoir Issue: Fines Migration
Fines migration may result from an unconsolidated or inherently unstable formation or from the use of an incompatible treatment fluid that liberates fine particles. The movement of fines such as silt, sand, or fine clay particles can damage the wellbore and stall well productivity. With the help of data integration, analysts can identify fines migration more readily, and begin fine migration management plans.
Since fines formations tend to be harder to spot in fields, analysts need a visual model that can read subtle hints of fines formations. For instance, declining production over the course of several weeks or months is a common indicator of fines migration buildup near the wellbore area. A software system that incorporates production data over time allows managers to read small problems that require further study.
By visualizing and analyzing data over time, users can achieve the following to navigate fines migration challenges:
- comprehension of the changing nature of the reservoir
- the simultaneous view of time-variant and multiple streams of information
- enhanced analytics of open hole logs, cuttings, and sidewall cores
As fines grow more prominent, analysts can know when to intercede and mitigate the damage done to the completion. Overall, the combined data analytics can further clarify the subsurface conditions of the reservoir, giving analysts more time to make correct decisions that address oil well problems seamlessly.
Resolve Oil Well Production Problems with CoViz 4D
CoViz 4D has the ability to combine multiple data streams to highlight areas of contention that may prevent operators from maximizing hydrocarbon goals. The unique tool not only shows hazards and anomalies, but it also offers cross-correlation features that allow teams to make connections between varying data streams, providing a haven for creative solutions to some of the toughest mechanical and reservoir conditions.
For the mechanical issues, CoViz 4D helps by comparing the unstructured production data in the problematic well with the normally producing surrounding wells. CoViz 4D also handles downhole hardware diagrams which are usually originally documented in paper drawings; these are helpful in comparing all wells for consistency or inconsistency in design that may lead to mechanical problems.
Reservoir issues usually require more effort to diagnose and remediate. In these cases, CoViz 4D can be particularly valuable because of its ability to visualize structured data (seismic, geologic models and interpretations, and reservoir models) alongside the unstructured production and well design data.
CoViz4D allows geoscientists, engineers, and all members of their teams to visualize and analyze multidisciplinary data in a comprehensive viewing environment to accurately pinpoint and resolve oil well production problems.
Image courtesy of Leonid Ikan