ERT - Ensemble based Reservoir Tool

21.1.1 verified Fri May 01 auth: no python

ERT (Ensemble based Reservoir Tool) is an open-source tool for ensemble-based reservoir management, including history matching, uncertainty quantification, and optimization. Current version is 21.1.1, with monthly releases following a versioning scheme based on calendar year and patch number.

pip install ert

Common errors

error ImportError: cannot import name 'ErtAnalysisError' from 'ert' ↓

cause The symbol is not exposed at the top-level package; it's in a submodule.

fix

Use 'from ert.analysis import ErtAnalysisError' instead.

error ModuleNotFoundError: No module named 'res' ↓

cause The old 'res' package was removed in ERT 21.0.0.

fix

Replace 'import res' with 'import ert' and update all dependent imports.

error TypeError: __init__() got an unexpected keyword argument 'ens_path' ↓

cause The API changed between versions; 'ens_path' is no longer accepted in the constructor.

fix

Check the ERT API documentation for the correct arguments or use the new configuration-loading approach.

error ert configdump: error: unrecognized arguments: --help ↓

cause The CLI interface changed; use 'ert --help' for top-level help.

fix

Run 'ert --help' or 'ert configdump --help' for subcommand help.

Warnings

breaking The 'res' and 'libres' packages have been removed. All imports must use the 'ert' package instead. ↓

fix Replace 'from res import *' with 'from ert import *' and update all import paths to use the new structure.

breaking Python 3.11 or later is required. Python 3.10 and earlier are not supported. ↓

fix Upgrade to Python 3.11 or newer.

deprecated The synthetic_forward_model keyword is deprecated. Use FORWARD_MODEL with a shell command instead. ↓

fix Replace 'SYNTHETIC_FORWARD_MODEL' with 'FORWARD_MODEL <shell_command>' in your configuration.

gotcha Configuration parsing may fail silently if the config file contains unknown keywords. Always validate with 'ert configdump'. ↓

fix Run 'ert configdump -v <config.ert>' to check for errors.

Imports

ErtAnalysisError
```
from ert.analysis import ErtAnalysisError
```
Commonly imported from old paths or submodules.
ert
wrong
```
import libres or import res
```
correct
```
import ert
```
The old 'res' or 'libres' package was merged into ERT. Use the top-level 'ert' package.
ErtScript
```
from ert.script import ErtScript
```
ErtScript base class for workflows.
ert_config
```
from ert.config import ErtConfig
```
Configuration parser.

Quickstart

Load an ERT configuration and demonstrate basic imports.

from ert import ErtConfig
from ert.analysis import ErtAnalysisError

# Load configuration from a file
config = ErtConfig.from_file("config.ert")
print(config)

# Minimal example to run an ensemble experiment
# (requires a valid ERT configuration file with forward model)
# For more details see https://ert.readthedocs.io/en/latest/