Core Facies & Sequence Analysis for Reservoir Characterization
Systematically classify lithofacies and build sequence stratigraphic models from well logs and cores
What You Can Do
You can rapidly interpret well logs, core descriptions, and seismic data to classify lithofacies associations, construct sequence stratigraphic frameworks, and generate facies distribution predictions across your field. Claude processes multiple well descriptions simultaneously to build repeatable facies analysis workflows, produce correlation frameworks, and create publication-ready facies summaries that directly inform exploration and development decisions.
Features
Systematically categorize grain size, sedimentary structures, paleontology, and depositional processes from core and log descriptions into discrete facies associations
Interpret genetic depositional sequences, identify key surfaces (SB, MFS, ts), and establish chronostratigraphic correlations across multiple wells
Generate structured summaries linking each facies to depositional setting, lateral extent, reservoir quality, and seal potential
Build facies-based cross-sections and correlation schemes for 5+ well datasets with confidence levels for each correlation
Map paleo-shorelines, paleoslope directions, and progradation/retrogradation patterns based on facies stacking patterns
Apply interpreted facies models to estimate likely lithofacies and depositional settings at exploration prospects or development locations
Rapidly backccheck your facies assignments and sequence models against published depositional analogs and case studies
Synthesize multi-well core studies and published literature into coherent basin-scale depositional narratives
Example Output
Example 1: Lithofacies Summary Table
| Facies Code | Lithology | Grain Size | Key Structures | Paleontology | Depositional Setting | Lateral Extent |
|---|---|---|---|---|---|---|
| F1 | Fine-grained sandstone | 0.1–0.25 mm | Ripple cross-lamination, bioturbation | Shallow marine benthics | Lower shoreface | Regional |
| F2 | Mudstone, silty | <0.063 mm | Laminated, organic-rich | Planktonic forams | Offshore transition | Field-wide |
| F3 | Coarse sandstone | 0.5–1.0 mm | Planar laminations, trough cross-bedding | Sparse bivalves | Upper shoreface | Local, NE trending |
Example 2: Sequence Stratigraphic Framework (3 wells)
Sequence JSA-2 spans 45–120 m TVD across all three wells. Lowstand Systems Tract (LST) shows incised channel sand (F3) in Well A, correlative estuarine mudstone (F4) in Well B. Transgressive Systems Tract (TST) records smooth shoreface progradation (F2→F1). Maximum Flooding Surface identified by offshore mud peak and planktonic foraminifer spike. HST shows regressive stacking (F1→F3) with 2° dip to NE.
Example 3: Facies Prediction for Prospect X
Based on dip-direction facies trends from Wells A–C, Prospect X (5 km NE) is expected to contain 60–80 m of upper shoreface sandstone (F3 equivalent), thinning basinward to shoreface transition mudstone. Estimated net:gross ~65%. Seal potential moderate (F2 regional mudstone). Analog: South Field play, similar paleobathymetry and progradation direction.
What's Included
- SKILL.md: Complete instruction file with overview, when-to-use guidance, and workflow structure
- Lithofacies Description Template: Standardized core description and facies coding framework
- Sequence Stratigraphy Checklist: Step-by-step guide to identify key surfaces, systems tracts, and sequence boundaries
- Well Correlation Workflow: Structured prompt templates for multi-well facies correlation and cross-section building
- Facies Association Table Template: Markdown table for organizing grain size, structures, paleontology, environment, and lateral extent
- Regional Analog Synthesis Framework: Method for backchecking interpretations against published case studies and depositional models
Who It's For
- Sedimentologists — Building facies frameworks and depositional models from well and core data
- Subsurface Geologists — Correlating wells across exploration and development fields using sequence stratigraphic principles
- Reservoir Characterization Teams — Predicting facies distributions and reservoir quality lateral to drilled locations
- Exploration Geoscientists — Integrating facies analysis into play-fairway mapping and prospect risk assessment
- Core Lab Specialists — Systematically documenting and classifying core lithofacies for regional database integration
Best For
- Interpreting 5+ well datasets to establish a consistent facies framework
- Building sequence stratigraphic models for field- or play-scale subsurface architecture
- Generating facies-based stratigraphic cross-sections for team presentations and subsurface maps
- Predicting lateral facies distributions and reservoir character at undrilled exploration targets
- Synthesizing depositional history from core descriptions and well logs into coherent basin narratives
- Backchecking facies assignments and paleoenvironmental interpretations against published analogs
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