The pVT facilities at SINTEF Reservoir laboratory supports research for CO₂-EOR and CO₂ saline aquifer storage. Process wetted parts are in corrosion resistant materials suitable for CO₂/brine mixtures. It has been used to characterise oil/brine/CO₂ fluid systems through:

• Determination of p-V curves (constant composition volume expansion curves) for original reservoir fluids and for mixtures of reservoir fluids and CO₂
• Determination of phase fractions for binary mixtures and for more complex mixtures such as reservoir fluids
• Characterisation of phase envelopes for CO₂-rich mixtures representative of CO₂ streams from capture processes
• Determination of expansion factors from reservoir conditions to ambient conditions
• Measurement of interfacial tension between oil/brine, oil/gas, oil/CO₂, brine/CO₂
• Determination of characteristics of chemicals for foam stabilisation or viscosity-altering substances for CO₂-EOR or CO₂ saline aquifer storage.
• Studies of oil/gas miscibility

The operative installations currently encompass:

Two automated pVT-cells

• Working conditions up to 700 bar, 200 °C for both cells
• Process volume up to 150 ml
• Windowed high-pressure cell enabling visual characterisation of the process fluids and accurate measurement of phase fractions
• In-cell rotary stirrer for rapid equilibration of fluids
• Possibility for mounting of camera
• Mounted in heating cabinet
• Cell inserts for studies of special conditions such as asphaltene precipitation and condensate drop-out
• CCS-related research has priority on one of the pVT-cells

Automated HPHT pVT cell

• Working conditions up to 1000 bar, 210 °C
• This cell is a free-standing benchtop apparatus with heating integrated in the cell body
• The basic design of the windowed cell is as for the 700 bar cells

Automated slim-tube apparatus

• Working conditions up to 700 bar, 150 °C
• Coiled sand-filled 12-m long tube
• Pore volume ~50 ml
• In-line measurement of fluid density at outlet

Two pendant drop cells for IFT measurements

• Working conditions up to 850 bar, 180 °C, and 2000 bar, 240 °C, respectively
• Corrosion resistant for CO₂/brine systems at high temperature and temperature
• High-resolution camera system combined with in-house image analysis software
• Measurement range down to ~1 mN/m
• Mineral samples can be inserted for studies of contact angle and contact angle alteration with time in mineral/CO₂/brine systems

Interface laser light scattering cell for ultra-low IFT measurements (~10^-5 mN/m)

• Working conditions up to 700 bar, 180 °C
• The typical application of this cell is for measurement on gas condensate systems and systems with very small density difference between the phases

Rolling-ball viscometer

• Working conditions up to 700 bar, 150 °C
• Measurement range 0.1–3 cP

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.

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.