Formation Damage Analysis via the REACTRAN Code

P. Ortoleva, C. Moore, J. Chadam

When aqueous fluids out of equilibrium with a formation are injected into that formation, a variety of processes can take place, including aqueous phase reactions, mineral nucleation/growth, dissolution, and transport. Our computer code, REACTRAN, solves reaction-transport equations for these processes. Because the fluid flows are often fast, some reactions may be far out of equilibrium. However, very fast reactions make straightforward simulation of the reaction-transport equations impractical. REACTRAN is a user-friendly code that allows for making some reactions fast (i.e., maintained at equilibrium while others are at finite rate), and simultaneously calculating changes of permeability. Input to the REACTRAN code includes the velocity of the well fluid and the composi ion and temperature of it and the reservoir rocks as well as equilibrium and rate constant data for the chemical reactions. The output of the code is the temporal evolution of the spatial distribution of primary and secondary minerals and porosity.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.