CLATHRATES - COMPUTER-PROGRAMS TO CALCULATE FLUID INCLUSION V-X PROPERTIES USING CLATHRATE MELTING TEMPERATURES

Knowledge of final clathrate melting temperatures is essential for est imates of salinity, bulk composition and density in H2O-gas-rich fluid inclusions by nondestructive methods. The salinities calculated stron gly depend on the thermodynamic model used, which involves many indepe ndent intensive properties and related parameters, such as osmotic coe fficients, fugacity coefficients, gas solubilities. Four programs have been developed (DENSITY, ICE, Q2, and NOSALT) using Turbo C++ version 3.0 to handle clathrate melting temperatures with several initiation procedures. These programs allow the calculation of bulk densities and compositions (V-X properties) for H2O-CO2-CH4-N-2-NaCl-KCl-CaCl2-rich fluid inclusions using the clathrate melting temperature in combinati on with liquid-vapour equilibria, data from Raman spectroscopic analys is of the nonaqueous phases, and volume fraction estimates of the phas es present. Calculations are restricted to fluid compositions less tha n eutectic salinities. If volume estimates are not provided, the progr ams calculate only the properties of the individual phases present in fluid inclusions during clathrate melting, including the salinity. Err ors in measured parameters and in volume fraction estimates, which may be relatively large, are also handled by the programs. (C) 1997 Elsev ier Science Ltd.