Electrofacies

petropy.electrofacies(logs, formations, curves, n_clusters, log_scale=[], n_components=0.85, curve_name='FACIES')[source]

Electrofacies function to group intervals by rock type. Also referred to as heterogenous rock analysis.

Parameters:
  • logs (list of ptr.Log objects) – List of Log objects
  • formations (list of formation names) – List of strings containg formation names which should be previously loaded into Log objects
  • curves (list of curve names) – List of strings containing curve names as inputs in the electrofacies calculations
  • n_clusters (int) – Number of clusters to group intervals. Number of electrofacies.
  • log_scale (list of curve names) – List of string containing curve names which are preprocessed on a log scale. For example, deep resistivity separates better on a log scale, and is graph logarithmically when viewing data in a log viewer.
  • n_components (int, float, None or string (default 0.85)) – Number of principal components to keep. If value is less than one, the number of principal components be the number required to exceed the explained variance.
  • curve_name (str (default 'FACIES')) – Name of the new electrofacies curve.
Returns:

list of petropy.Log objects
Return type:

list

Examples

>>> # loads sample Wolfcamp calculates electrofacies for that well
>>> import petropy as ptr
# reads sample Wolfcamp Log from las file
>>> log = ptr.log_data('WFMP')
>>> logs = [log]
>>> f = ['WFMPA', 'WFMPB', 'WFMPC']
>>> c = ['GR_N', 'RESDEEP_N', 'RHOB_N', 'NPHI_N', 'PE_N']
>>> scale = ['RESDEEP_N']
>>> logs = ptr.electrofacies(logs, f, c, 8, log_scale = scale)

>>> import petropy as ptr
# loads logs from a list of paths and
# calculates electrofacies across the wells
#
# defin file_paths for las files to analyze
>>> file_paths = ['path/to/log1.las', 'path/to/log2.las',
... 'path/to/log3.las', 'path/to/log4.las']
# create list of Log objects
>>> logs = [ptr.Log(x) for x in file_paths]
# define csv with tops for all wells
>>> tops_csv = 'path/to/tops.csv'
# add formation tops to wells
>>> for log in logs:
...     log.tops_from_csv(tops_csv)
# define list of formation tops. If single formation, f = ['FORM']
>>> f = ['FORM1', 'FORM2']
# list of curves to use for classification
>>> c = ['GR_N', 'RESDEEP_N', 'RHOB_N', 'NPHI_N', 'PE_N']
>>> scale = ['RESDEEP_N']
# run electrofacies across logs in list
>>> logs = electrofacies(logs, f, c, 8, log_scale = scale)
# save las in renamed file
>>> for i, log in enumerate(logs):
...     new_file_name = file_paths[i].split('.')[0]+'_with_HRA.las'
...     log.write(new_file_name)