Photo: Christian Ove Carlsson

CERE Seminar by Teresa Regueira Muniz "Extended PVT study of high pressure-high temperature reservoir fluids including the reverse Joule-Thomson effect"

"Extended PVT Study of High Pressure-high Temperature Reservoir Fluids Including the Reverse Joule-Thomson Effect"


As a general trend, dwindling conventional oil and gas resources along with an increasing demand for oil inevitably push more production activities in challenging environment such as deeper reservoirs characterized by high pressure-high temperature (HPHT) conditions. Consequently, there is a need to extend the conventional PVT (phase equilibrium and physical properties) study to HPHT conditions and to address the specific issues associated with the production in HPHT reservoirs. For high pressure reservoirs, accurate measurement and modelling of volumetric properties are crucial since fluid compressibility is one of the major production mechanisms. In addition, a special concern is the Joule-Thomson effect due to large pressure drop in the production. The Joule-Thomson coefficients are usually negative for HPHT fluids, corresponding to a temperature rise upon pressure drop. The “reverse” Joule-Thomson effect is important to accurate temperature measurement as well as safe production.

This study presents a systematic experimental study of two HPHT reservoir fluids, one gas condensate and another volatile oil, in the temperature range from (25 to 200)°C and pressure up to 1400 bar. Their saturation pressures at different temperatures were measured by use of a PVT cell from Sanchez Technologies consisting of a variable volume cell with full visibility. The liquid fractions in the two-phase regions were also measured. The single-phase densities were measured in an Anton Paar DMA-HPM high pressure vibrating tube densimeter. The Joule-Thomson coefficients were determined indirectly through measurement of density values and isobaric heat capacity values. The isobaric heat capacities were measured in a Setaram C80 Calvet type differential heat-flux calorimeter using a method similar to that described by Bessières et al. [1]. For measurement at extreme pressures, self-designed cells allowing circulation of fluid were used. By combining the obtained density and heat capacity measurements, we provide in this work values of the Joule-Thomson coefficients in the temperature range from (60 to 175)°C from (100 to 1200) bar. The obtained values of this coefficient were negative under the studied conditions, indicating an increase of temperature for an isenthalpic expansion of the studied fluids.

Additionally, the measured experimental data were modelled using both classical cubic EoS’s (SRK and PR) and an advanced non-cubic EoS (PC-SAFT). The characterization method of Varzandeh et al. [2] was used to apply PC-SAFT to reservoir fluids. The two types of EoS were compared for prediction of phase envelopes and densities.


1. D. Bessières, H. Saint-Guirons, J.-L. Daridon, J. Therm. Anal. Calorim. 62 (2000) 621-632.

2. F. Varzandeh, E. H. Stenby, W. Yan, Fluid Phase Equilib. 433 (2017) 97-111.


Thu 19 Apr 18
9:00 - 10:00