Petrophysical analysis of Niger Delta well log data using Python, featuring facies discrimination, Reservoir Quality Index (RQI) engineering, and Net Pay quantification with a 40.24% NTG result.
# Reservoir Quality Analysis — GCA Capstone Project
A data-driven petrophysical analysis of well log data to identify and quantify the best-quality reservoir intervals in a Niger Delta well.
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## Project Objective
This project focuses on identifying the best quality rock (reservoir) using data logic applied to wireline log data from **Well A** (a Niger Delta well). By combining statistical facies discrimination, feature engineering, and boolean filtering, the analysis delivers a quantified Net Pay result that can directly inform field development decisions.
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## Workflow
1. **Import Libraries**: `lasio`, `numpy`, `pandas`, `matplotlib`, `seaborn`
2. **Dataset Loading & Cleaning**: Load `.LAS` file, handle null values, inspect well metadata and curve information
3. **Statistical Facies Discrimination**: Gamma Ray histogram analysis to justify and select GR cutoffs
4. **Feature Engineering**: Compute the Reservoir Quality Index (RQI)
5. **Net Pay Quantification**: Apply pay sand criteria and calculate gross thickness, net pay, and NTG
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## Key Results
| Metric | Value |
|---|---|
| Reservoir Gross Thickness | ~941.98 m |
| Net Pay Thickness | ~379.02 m |
| Net-to-Gross (NTG) | **40.24%** |
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## Methods & Techniques
### GR Cutoffs (Niger Delta Context)
The Gamma Ray histogram reveals a **bimodal distribution** consistent with interbedded sand-shale sequences of the **Agbada Formation**. Two cutoffs were evaluated:
- **60 API** (industry standard) — conservative cutoff for clean sand discrimination
- **75 API** (high-side) — captures marginal sands in the transition zone
### Reservoir Quality Index (RQI)
A custom feature engineered to move beyond simple lithology identification:
```
RQI = Porosity × (1 − GR_norm)
```
GR values are normalised to a 0–1 range (0 = cleanest sand, 1 = purest shale), making RQI a dimensionless index that highlights intervals that are **both clean and porous** — the most productive sands.
### Net Pay Criteria
Pay sands …