P005 Determination of the Acoustic Properties of Hydrocarbon Rich Gases Using PVT Relations A. Shams* (Heriot-Watt University) C. Macbeth (Heriot-Watt University) & F. Gozalpour (Heriot-Watt University) SUMMARY Published approaches for determining the seismic properties of pore fluids are investigated to examine the effect of gas quality at constant pressure and temperature. For this purpose a range of fluids from natural gas to rich gas condensate is prepared and tested to determine pertinent acoustic properties of the fluid at single-phase conditions. The results show that the ratio of heat capacities of fluids in currently used models do not vary with the