CODEWITHSUNDEEP
pythonlaslog-ascii-standard
Kevin Nguyen
Kevin Nguyen

Reputation: 33

LAS files - Python

I'm pretty sure this is a very menial question about LAS files, but I wasn't entirely sure how to google this. For context, I'm trying to create a plot given the information in a LAS file.

import lasio as ls
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

well = ls.read(r'1051325649.las')
df = well.df() 

fig = plt.subplots(figsize=(10,10))

#Set up the plot axes
ax1 = plt.subplot2grid((1,3), (0,0), rowspan=1, colspan = 1) 
ax2 = plt.subplot2grid((1,3), (0,1), rowspan=1, colspan = 1)
ax3 = plt.subplot2grid((1,3), (0,2), rowspan=1, colspan = 1)

ax1.plot("GR", "DEPT", data = df, color = "green") # Call the data from the well dataframe
ax1.set_title("Gamma") # Assign a track title
ax1.set_xlim(0, 200) # Change the limits for the curve being plotted
ax1.set_ylim(400, 1000) # Set the depth range
ax1.grid() # Display the grid

The LAS file pretty much looks like this where I want to create a plot where the far left column "DEPT" should be the X-axis. However, the "DEPT" or depth column isn't able to be made into a format to allow for me to plot it. **Note: there is a GR column on the right not in this picture, so don't worry. Any tips would help greatly.

enter image description here

Upvotes: 2

Views: 4077

Answers (2)

Amir Charkhi
Amir Charkhi

Reputation: 846

When reading .las files using lasio library and converting them to pandas dataframe, it automatically sets DEPT as the index for the dataframe.

There are two solutions for this problem:

  1. Use the data as-is:
import matplotlib.pyplot as plt
import lasio

well = lasio.read('filename.las')
well_df = well.df()

plt.plot(well_df.GR, well_df.index)

And well_df.index will be the DEPT values.

  1. Reset the index and use DEPT as a column
import matplotlib.pyplot as plt
import lasio

well = lasio.read('filename.las')
well_df = well.df()

well_df = well_df.reset_index()

plt.plot(well_df.GR, well_df.DEPT)

Upvotes: 1

kii
kii

Reputation: 497

Short answer:

plt.plot expects that both "GR" and "DEPT" are columns in df, however the latter (DEPT) is not a column, it is the index. You can solve it by converting the index in df to a column:

df2 = df.reset_index()
ax1.plot("GR", "DEPT", data = df2, color = "green")

Upvotes: 1

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