Solve challenging subsurface flow problems with PetraSim

PetraSim is the graphical module for the TOUGH2 family of simulators. Developed at Lawrence Berkeley National Laboratory, TOUGH2 and its derivatives are recognized for their powerful simulation capabilities for fluid flow and heat transfer in porous and fractured media.

The TOUGH2 codes have been applied to problems ranging from Yucca mountain groundwater flow to multi-component environmental remediation. PetraSim makes the power of TOUGH2 accessible to modelers through an interactive 3D environment that includes mesh generation, parameter definition, and display of results.

PetraSim significantly lowers the barriers to TOUGH2 use by freeing the analyst to focus on the model, while automatically handling the complex details of TOUGH2 input and output files.

PetraSim includes TOUGH2 (version 2), T2VOC, TMVOC, and TOUGHREACT (version 1.2) executables. Newer versions of TOUGH and TOUGHREACT, including TOUGH3 and TOUGHREACT v3.32/4.13, are supported with licensing purchased through LBL.

The TOUGH2 (version 2) executables packaged with PetraSim include changes to the TOUGH2 source code available only with PetraSim. This includes the output of CSV files (used for results visualization within the interface) and a number of changes designed to improve geothermal models. There are detailed in this paper and include (but are not limited to) the following:

• Specify the start-up time for a well on deliverability. This avoids the need for multiple restarts when modeling a number of make-up wells in field-scale geothermal production forecast.
• Specify the productivity index (PI) and flowing pressures for each layer of a well on deliverability.
• IAPWS-IF97 correlations for pure water added to the standard TOUGH2 EOSs. These extend the use of TOUGH2 to near-critical conditions (T>350°C) and to geothermal geopressured conditions (P>1000 bara).
• IAPWS 2008 viscosity formulation for pure water and steam added to the standard TOUGH2 EOSs.
• Grouping of source/sink cells using source/sink names. This makes it possible to correctly assign production when multiple wells intersect the same cell.
• Writing of SAVE file at specified time steps.
• Additional results output in GOFT file for EOS2 and EWASG.
• New capillary pressure and enthalpy options in EOS2 and EWASG.
• Improved convergence during EOS2 change of phase.

Applications for PetraSim and the simulators it supports include:

• Coupled process modeling (thermal, hydrologic, chemical, mechanical, biological)
• Carbon sequestration and other types of injection
• Performance assessment of nuclear waste repositories
• Geothermal reservoir studies
• Vadose zone hydrology
• Fate and transport of volatile organic compounds
• Design and analysis of laboratory and field experiments