MiniRes

A lean petroleum reservoir simulator using TPFA (two-point flux approximation). Documentation.

• Small: all of its physics fit in core.py's 400 lines of code.
• Capable: two-phase, slight compressibility, BHP control, well paths, irregular outlines and faults (inactive cells), aquifers – but a toy: 2D uniform grid, immiscible, isothermal, and simple well models and operation.
• Adjoint model included; verified against finite differences.
• Python: (pip install minires), or demo it in a web browser via (backend: Google) or (no backend!).
• Fast: similar to JutulDarcy's (but no JIT startup/wait) at equal accuracy on 2D two-phase cases of size $100$ – $10^5$.
• Reliable: reproduces the numbers of the Matlab code (2007) from NTNU/Sintef by Jørg E. Aarnes, Tore Gimse, and Knut–Andreas Lie. Further validated against Buckley–Leverett's analytic solution, ECLIPSE's numbers on the Egg model and JutulDarcy's on quarter five-spot, SPE-10, and Egg.
• Tested extensively: , with many examples doubling as regression tests.

Used by

Please let me know (or make a PR) if you use this in your work, and I will add it to this list.

• History matching tutorial

Contributions

To also get the examples and tests, clone instead, and install with uv, in editable mode:

git clone https://github.com/patnr/MiniRes.git
cd MiniRes
uv sync  # or: pip install -e .
uv run pytest
uv run ruff check

AI

AI (in particular Claude Code) has already played a major role in developing the recent features here, so AI-generated contributions are welcome. But there is a strong focus on minimising slop, meaning that the changes should be as small as the job allows, and written in the style of what surrounds them. CLAUDE.md carries conventions and a good deal of what has already been tried and rejected.