ANNOUNCING ECHELON 2026.2

New features in this release, developed by the ECHELON Consortium Team in Milan and North America, include:

Python scripting

ECHELON now installs with an embedded Python interpreter and its own Python module, echpy, giving user scripts access to simulator data and state at different stages of the simulation. Scripts can modify model data, change well controls, and carry out other workflows that are easier to express in Python than in keyword input. They can draw on standard Python packages such as numpy, pandas, and scipy, which ship with ECHELON and need no further setup, and they can act both when the grid and its properties are being set up and when the production schedule is running.

Array arithmetic expressions

A new free-form expression facility (the ARITHMETIC keyword) lets users build and modify grid, property, and region arrays with formulas that can include mathematical functions and conditional logic, instead of chaining together conventional array-editing keywords. Expressions can be limited to parts of the grid, including local grid refinements (LGRs), and can be used throughout the input, from grid definition to the schedule.

Coal bed methane model for compositional fluids

The coal bed methane model, introduced for black-oil models in ECHELON 2024.1, is now also available for compositional models. Each hydrocarbon component adsorbs and desorbs individually, driven by its own partial pressure, either instantaneously or at its own rate. Components can also be made to compete for a shared adsorption capacity, which enables physically consistent modeling of the displacement of adsorbed methane by injected carbon dioxide. As in black-oil, the model applies equally to shale gas formations. The coal bed methane model is compatible with both dual-porosity and dual-permeability models.

User-defined quantities in reservoir coupling

User-defined quantities (UDQs) are now fully supported at the field-scheduling level of an ECHELON Reservoir Coupling (ERC) run, so that field-wide strategies spanning several coupled reservoirs can be expressed directly: for example, a well target derived from production across all reservoirs, or a comparison between wells in different reservoirs. These quantities can set well targets and other field-scheduling controls and trigger conditional actions; they are reported in the field-level summary output and carry through restarts. Quantities defined for the field and within each reservoir are kept independent, so identically named quantities never clash.

Network coupling enhancements

For wells that are coupled to FNS at the wellhead and whose response is intrinsically non-monotone, ECHELON has the option to pass the complete inflow-performance curve to FNS. FNS can then select the stable operating point when the well and network curves intersect more than once. This applies to both producers and injectors. In addition, network constraints, boundary conditions, and branch targets can now be set from field-level UDQs, allowing them to follow values computed during the run.

Other features and improvements

- Pinchouts at the interface between LGRs and their host grid are now handled reliably.

- Flow is now represented across a fault between two vertically stacked LGRs where the fault throw brings their cells into contact.

- Summary output for cell-based quantities is now available for LGR cells.

- A new option controls how the rock volume of a dual-porosity or dual-permeability model is divided between matrix and fracture cells, which affects features that depend on it, such as rock heat storage and coal adsorption.

- The connection report now identifies the origin of every connection (user-defined, fault, pinchout, LGR, matrix-fracture, or a combination of these), making it easier to check how the grid has been connected.

- The solver log now summarizes nonlinear convergence in one compact row per Newton iteration, for both black-oil and compositional runs, making it quicker to diagnose models that struggle to converge.

Please contact Stone Ridge Technology to obtain this 2026.2 release of ECHELON for use in your evaluations, or for additional information on ECHELON software’s capabilities.