User’s Manual for the
HYDRATE v1.5 Option of TOUGH+ v1.5:
A Code For The Simulation Of System Behavior In
Hydrate-Bearing Geologic Media
George J. Moridis
Earth Sciences Division, Lawrence Berkeley National Laboratory
University of California, Berkeley, California
Abstract
HYDRATE v1.5 is a numerical code that for the simulation of the behavior of
hydrate-bearing geologic systems, and represents the third update of the code since its
first release [Moridis et al., 2008]. It is an option of TOUGH+ v1.5 [Moridis, 2014], a
successor to the TOUGH2 [Pruess et al., 1999] family of codes for multi-component,
multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory.
HYDRATE v1.5 needs the TOUGH+ v1.5 core code in order to compile and execute. It
is written in standard FORTRAN 95/2003, and can be run on any computational platform
(workstation, PC, Macintosh) for which such compilers are available.
By solving the coupled equations of mass and heat balance, the fully operational
TOUGH+HYDRATE code can model the non-isothermal gas release, phase behavior and
flow of fluids and heat under conditions typical of common natural CH
4
-hydrate deposits
(i.e., in the permafrost and in deep ocean sediments) in complex geological media at any
scale (from laboratory to reservoir) at which Darcy’s law is valid.
TOUGH+HYDRATE v1.5 includes both an equilibrium and a kinetic model of
hydrate formation and dissociation. The model accounts for heat and up to four mass
components, i.e., water, CH
4
, hydrate, and water-soluble inhibitors such as salts or
alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice
phase and hydrate phase). Hydrate dissociation or formation, phase changes and the
corresponding thermal effects are fully described, as are the effects of inhibitors. The
model can describe all possible hydrate dissociation mechanisms, i.e., depressurization,
thermal stimulation, salting-out effects and inhibitor-induced effects.
