Target formation is missing in the well
The targeted formation might be missing when drilling a well if insufficient exploration was carried out and lead to encounter unexpected geological structure or inaccurate positioning of the target. It can also be caused by inadequate analysis of exploration data (seismic, well data, core drill etc.) or may result from mistake of drilling operator when descending towards the reservoir. It is generally limited by thorough exploration work and precise seismic data interpretation.
Informations
- Category: Risks due to subsurface uncertainties
- Id: D-9
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Phases:
- Drilling / Testing
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Consequences:
- Economic / Performance / Acceptability
Mitigation
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Prevention:
- Additional investigation early in the project to provide accurate interpretation of expected geology and information on the target reservoir (e.g. geophysical methods)
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Monitoring:
- Thorough geological survey/core sample analysis
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Corrective measures:
- Drilling further
- Test aquifers encountered during the descent of drilling tool (before casing is placed) and find suitable water bearing formation in the already drilled section
- Use well to explore other reservoirs
- Convert to closed loop system
More information is available on the project deliverable (link), or navigate on the online version.
