lasio

name	lasio
description	Read, write, and manipulate LAS (Log ASCII Standard) well log files for borehole geophysical and petrophysical data. Use when Claude needs to: (1) Read/parse LAS 1.2 or 2.0 files, (2) Extract well headers or curve data, (3) Convert LAS to DataFrame/CSV/Excel, (4) Create new LAS files from arrays, (5) Modify existing LAS files, (6) Handle problematic or malformed LAS files, (7) Batch process multiple well files.
version	1.0.0
author	Geoscience Skills
license	MIT
tags	["Well Logs","LAS","Petrophysics","Data I/O","Lasio","CWLS","Wireline","Borehole"]
dependencies	["lasio>=0.30"]
complements	["welly","petropy","striplog"]
workflow_role	data-loading

lasio - LAS Well Log Files

Quick Reference

import lasio

# Read
las = lasio.read("well.las")

# Access data
df = las.df()                    # DataFrame (depth as index)
gr = las['GR']                   # Single curve as numpy array
depth = las['DEPT']

# Well info
well_name = las.well['WELL'].value
uwi = las.well['UWI'].value

# Write
las.write('output.las')

Key Classes

Class	Purpose
LASFile	Main container - holds headers, curves, data
CurveItem	Single curve with mnemonic, unit, data array
HeaderItem	Header entry (mnemonic, unit, value, descr)

Essential Operations

Read and Inspect

las = lasio.read("well.las")
print(las.curves.keys())         # Available curves
print(las.well)                  # Well section headers
print(las.version)               # LAS version info

Access Curve Data

# As numpy arrays
gr = las['GR']
depth = las['DEPT']

# With metadata
curve = las.curves['GR']
print(curve.unit, curve.descr)   # 'GAPI', 'Gamma Ray'

Create New LAS

import numpy as np

las = lasio.LASFile()
las.well['WELL'] = lasio.HeaderItem(, value=)
las.well[] = lasio.HeaderItem(, value=)

depth = np.arange(, , )
las.append_curve(, depth, unit=, descr=)
las.append_curve(, gr_data, unit=, descr=)
las.write()