Coupling IPhreeqc with UTCHEM to model reactive flow and transport

A detailed step-by-step algorithm is presented through which we integrate IPhreeqc of the United Stated Geological Survey (USGS) state-of-the-art geochemical package with UTCHEM for comprehensive reactive-transport modeling. UTCHEM is 3D multi-phase flow and transport research simulator developed in The University of Texas at Austin. On the other hand, IPhreeqc is the open-source modules of the USGS state-of-the-art geochemical package, PHREEQC. Through this coupling, we are able to simulate homogeneous and heterogeneous, irreversible, and ion-exchange and surface reactions under non-isothermal, non-isobaric and both local-equilibrium and kinetic conditions. All the data communications between UTCHEM and IPhreeqc is performed through the computer memory without writing/reading files. We further parallelize the geochemistry module of UTCHEM-IPhreeqc in order to conduct field scale reservoir simulations. Our proposed coupling procedure can be implemented in any existing reservoir simulator for comprehensive reactive-transport modeling. One realistic case study is presented using UTCHEM-IPhreeqc.