( Reservoir Mapping Method )
Reservoir Mapping: Advanced Methods for Well Placement
Reservoir mapping represents the highest level of geosteering proficiency. While the “Model, Compare, and Update” method focuses on the path of a single wellbore, consequently, this practice involves integrating data into a larger, multi-dimensional view of the entire reservoir. Furthermore, by mapping the subsurface architecture, you move from simply “staying in zone” to actively defining the boundaries of the field.
Integrating Data for Field Development
Effective analysis requires you to synthesize disparate data streams into a cohesive geological map. For instance, you compare your real-time LWD data against all offset wells in the field rather than relying solely on a type log. As a result, this allows you to “connect the dots” between wells and identify trends in reservoir quality.
- Seismic Integration: You overlay your current well path onto 3D seismic cubes. If your well path deviates from the seismic prediction, the reconciliation process often leads to discoveries of new fault blocks.
- Property Trends: Beyond just locating the formation, you evaluate reservoir characteristics. By mapping porosity and resistivity trends, you can identify high-permeability “sweet spots” that were not visible in initial planning.
Why Field-Scale Analysis Matters
First, accurate visualization helps determine the most productive locations for future infill wells. Additionally, mapping allows you to detect geological hazards, such as water-bearing compartments, well before the bit reaches them. Finally, maximizing the recovery factor provides significant value to the operator, which you can read more about on the Society of Petroleum Engineers (SPE) website.
Common Challenges in Subsurface Modeling
In new fields, you may be the first to map a specific area; therefore, your real-time interpretation becomes the “ground truth” for the entire project. However, this work requires geological intuition and proficiency with complex 3D modeling software.
Learning Objectives
This lesson provides the final piece of the Advanced Well Placement puzzle. You will learn:
- How to integrate real-time drilling data into 3D regional geological models.
- Techniques for multi-well correlation and field-wide analysis.
- How to update field-wide seismic interpretations based on drilling results.