striplog - Lithological Logs

Quick Reference

from striplog import Striplog, Interval, Component

# Create from intervals
intervals = [
    Interval(top=0, base=10, components=[Component({'lithology': 'sandstone'})]),
    Interval(top=10, base=25, components=[Component({'lithology': 'shale'})]),
    Interval(top=25, base=40, components=[Component({'lithology': 'limestone'})]),
]
strip = Striplog(intervals)

# Load from file
strip = Striplog.from_csv('lithology.csv')  # Columns: top, base, lithology

# Access and display
print(strip)
strip.plot()
df = strip.to_dataframe()

Key Classes

Essential Operations

Create from CSV

# CSV format: top,base,lithology
strip = Striplog.from_csv('lithology.csv')
strip.plot()

Create from Description Text

from striplog import Striplog, Lexicon

description = """
0.0 - 5.5 m: Fine to medium sandstone
5.5 - 12.0 m: Grey shale with silt laminations
12.0 - 18.5 m: Massive limestone, fossiliferous
"""
strip = Striplog.from_description(description, lexicon=lexicon)

Query and Extract

# Get interval at depth
interval = strip.read_at(z=15)
print(interval.primary.lithology)

# Crop to depth range
subset = strip.crop((10, 30))

# Unique lithologies
lithologies = strip.unique('lithology')

Statistics

# Net-to-gross for specific lithology
ntg = strip.net_to_gross(pattern={'lithology': 'sandstone'})
print(f"Sandstone: {ntg * 100:.1f}%")

# Merge adjacent same-lithology intervals
merged = strip.merge_neighbours()

Well Correlation

import matplotlib.pyplot as plt

wells = [Striplog.from_csv(f'well{i}.csv') for i in range(1, 4)]
fig, axes = plt.subplots(1, 3, figsize=(10, 8), sharey=True)

for ax, well, name in zip(axes, wells, ['Well 1', 'Well 2', 'Well 3']):
    well.plot(ax=ax, legend=legend)
    ax.set_title(name)

plt.tight_layout()
plt.savefig('correlation.png')

Export

strip.to_csv('output.csv')
strip.to_las('output.las')
strip.to_json('output.json')
df = strip.to_dataframe()

Hatch Patterns

When to Use vs Alternatives

Use striplog when you need to represent geological intervals (lithology, facies) as structured objects with querying, statistics, and correlation.

Use welly instead when working with continuous well log curves (GR, RHOB). Welly and striplog complement each other -- welly for curves, striplog for lithology intervals.

Use custom matplotlib instead for simple, one-off stratigraphic columns where you don't need interval querying or net-to-gross calculations.

Common Workflows

Create lithological log from CSV data

- [ ] Prepare CSV with columns: top, base, lithology (optionally color)
- [ ] Load with `Striplog.from_csv('lithology.csv')`
- [ ] Define Legend with colors and hatch patterns for each lithology
- [ ] Verify intervals: check for gaps or overlaps
- [ ] Merge adjacent same-lithology intervals with `merge_neighbours()`
- [ ] Compute statistics: `net_to_gross()`, `unique()`
- [ ] Plot with legend and export to desired format

Common Issues

References

• Lexicon Configuration - Rock type dictionaries and synonyms
• Component Definitions - Properties and multi-attribute intervals

Scripts

• scripts/create_striplog.py - Create striplog from CSV or text data