pVT (NO3.7c)

The pVT facilities at SINTEF Reservoir laboratory consist of pressure cells and apparatuses for studies of fluid systems at reservoir conditions. The individual installations can be used for detailed characterisation of the pVT behaviour of fluid systems used in core flooding experiments, and for stand-alone studies of fluid systems at reservoir conditions.

The pVT facilities at SINTEF Reservoir laboratory is working in close collaboration with other ECCSEL facilities at SINTEF, such as the co-located core flooding facilities (ECCSEL facility NO3.7a). Services such as advanced characterisation of the composition (mass spectroscopy) of fluid samples are possible at other SINTEF laboratories.

The pVT facilities at SINTEF Reservoir laboratory is well equipped to perform a wide range of fluid studies under reservoir conditions relevant for CO₂ storage and CO₂-EOR. The overall maximum working conditions are 700 bar/150 °C and for the HPHT IFT cell up to 2000 bar/ 240 °C. All basic fluid properties necessary for interpretation of core flooding studies may be measured in the laboratory.

The facilities are also well suited for studies of phase equilibrium of binary mixtures relevant for research of the impact of impurities in the CO₂ stream, e.g. for CO₂ transport research, with pressure and temperature read-out accuracy of 0.01 bar and 0.02 °C, respectively. The pVT cells have an internal rotary stirrer integrated into the piston top. The stirrers are driven with magnetic coupling that avoids additional penetration of the seal. The stirring enables rapid equilibration of the process fluids at each measurement step.

The IFT cells are mounted on (semi)circular rails that facilitated rocking movements to speed up equilibration of the phases in the cells. This mounting also easily facilitates switching between pendant and rising drops. The IFT cells are equipped with several auxiliary ports to enable accurate control of the process pressure during forming of new drops at the needle tip. Manually operated pistons with small volume enables accurate control of drop volume during equilibration. Several needle sizes are available to expand the formation of stable drops for a wide range of phase density differences and IFT values.

All facilities are well ventilated, and the laboratory is equipped to handle poisonous substances such as SO₂ and CO.

The laboratory contains the only high-pressure interface laser light scattering IFT cell currently in operation (globally). The light scattering cell relies on the reflection/scattering of light from a stable horizontal interface between the phases in the cell and is therefore ideally suited for measurement on fluid systems with very low interfacial tension (down to 10^-5 mN/m) and/or with low density difference that makes the pendant drop technique impossible. This is most relevant for gas condensate systems or systems at near-critical conditions.