Introduction to MRST 2012b

MRST 2012a is a major release in terms of new features. We especially highlight the following

• A new module for fully implicit simulators with automatic Jacobian calculations.
• A new module for doing flow diagnostics.
• A new module for Discrete Fracture Matrix (DFM) simulations.
• The previously separate module for vertical equilibrium CO₂ models has been integrated into MRST as a regular module.

The new features have been extensively tested in-house—but discretion is advised when adopting the features in your own work-flows or research.

Please review the Upgrade Notes at the end of this document if you're upgrading from a previous edition of MRST.

Acknowledgements 

Work by the following developers constitutes this release of MRST

• Stein Krogstad
• Knut-Andreas Lie
• Olav Møyner
• Halvor Møll Nilsen
• Bård Skaflestad

The developers would also like to acknowledge the following persons for valuable contributions to this release of MRST

• Josten R. Natvig
• Eirik Keilegavlen
• Tor Harald Sandve
• Jhonatan Camacho

Olav Møyner acted as primary release manager for MRST 2012b.

New developments in MRST 2012b

We would like to point out a number of new developments in this release.

• MRST 2012b introduces a framework for creating simulators based on automatic differentiation. This enables fast prototyping of new models for reservoir flow since the computation of Jacobians is done automatically. Included within are three fully implicit simulators which use automatic differentiation: 
  
  • A black oil simulator (Oil/Water/Gas with gas dissolved in oil)
  • A oil and water simulator
  • A oil, water and polymer simulator

To activate the fully implicit module, enter

mrstModule add ad-fi

Please note that the fully implicit solvers are still under active development. Especially functionality relating to wells and linear equation solvers should be regarded as beta software which is subject to change.

• A flow diagnostics module that includes tracer partitioning and time of flight calculations for upscaling evaluation and analysis of well effects.

To activate the flow diagnostics module, enter

mrstModule add ad-fi

• The previously separate vertical-equilibrium module has been integrated into MRST and is released along with the 2012b release. New in this version is an implementation based on saturation values which can be used with existing solvers. A general effort has been done to make the implementation easier to read and maintain.

To activate the vertical equilibrium module, enter

mrstModule add vertical-equil

• The upscaling module has been updated with functions for relative permeability upscaling, including functionality for capillary and viscous limits as well as rudimentary support for periodic grids.
• A new module for Discrete Fracture Matrix (DFM) simulations contributed by Tor Harald Sandve and Eirik Keilegavlen. This module lets users solve problems involving fractures on unstructured grids.

To activate the DFM module, enter

mrstModule add dfm

• Some common MRST idioms have been added to the gridtools module to make prototyping easier for developers unfamiliar with MRST internals. See gridAddHelpers for more information.
• A simple volume renderer has been added under the name plotGridVolumes. While computationally more expensive than existing plotting functions, it allows at a glance visualization of inner parts of 3D grids. The syntax is similar to plotCellData.
• Support for MRST on Windows has in general been improved as a general effort has been made to repair the build process on Windows for compiled (.mex) files and other utilities using OS specific features.
• The deckformat module has been updated with preliminary support for reading restart and summary files. Note that this functionality is not considered mature and is limited to partial support for the version 7 of the EGRID format.

If you encounter a software issue using one of SINTEF Applied Mathematics' official modules, then please do not hesitate to contact the authors, for instance by sending an e-mail to Bård Skaflestad.

Upgrade notes

The following user-visible changes have been made to existing functions and data structures since the previous release of MRST.

• The function removeCells now correctly alters geometry fields when given a grid where computeGeometry has been applied.
• The function plotWell has been altered to give better default plots when called with default parameters for both realistic and synthetic grids.
• The function refineUniform in the agglom module now correctly refines 1xN strips of cells.
• Corrected two programming errors in the deckformat module that, together, contributed to a size mismatch and subsequent assignment error when attempting to expand a PVTO table through translating two independent undersaturated data records into earlier records.
• The function upscalePerm in the upscaling module now defaults to TPFA discretizations. A new keyword ‘method’ can be used to reselect mimetic discretization for cases when grid orientation effects are significant.
• The following files has been moved from the msmfem module to the coarsegrid module:
  • compressPartition
  • partitionCartGrid
  • partitionLayers
  • partitionUI
  • processPartition
• The msmfem module is no longer loaded by default. Note that along with the changes to the coarsegrid module, this may mean that existing programs written for MRST now depend on the coarsegrid module. Users should update their files accordingly. If you experience error messages such as

Undefined function 'partitionUI' for input arguments of type 'struct'.

this indicates that the script depends on the coarsegrid module.