Qatar Complex Fluid Laboratory
The Qatar Complex Fluid Laboratory focuses on fluid, pore-space and pore-surface interactions relevant to improving our understanding of carbon sequestration and CO2-driven enhanced oil recovery. Experimental and modelling approaches are complimentary.
Micro-fluidic micro-models of realistic pore-space images with varying complexity allow fundamental flow processes to be observed for different reservoir fluids: hydrocarbons, brines, and gases such as CO2. These flows are modelled using state-of-the-art Lattice-Boltzmann simulations developed in-house. The rheology of mixtures of reservoir fluids and supercritical CO2 is studies using our advanced controlled stress rheometer with its high pressure cell.
A fundamental requirement in developing successful CCS technology is a knowledge and understanding of both the thermodynamic phase equilibria and transport properties of CO2, not only in its pure form but also in mixtures of other fluids encountered in capture-and-storage processes, including water, brines and hydrocarbons.
Traditionally, cubic equations of state have been the thermodynamic modelling tool of choice, while viscosity has been either estimated with simple mixing rules or modelled using empirical correlations. However, the predictive power of these techniques is quite poor when applied to complex fluid systems such as these. Instead, QCCSRC employs progressive molecular-based modelling techniques.
Reservoirs are usually capped with an almost impermeable rock, which seals in the fluids. To determine the flow properties of these rocks, a dynamic pressure transmission experiment has been developed to speed up the measurement of capillary entry pressure and permeability, two parameters critical for estimating the storage capacity of the reservoir. The pressure transmission measurement can also be combined with X-ray CT imaging to visualize the response of micro-cracks to the changes in the state of effective stress.
Modelling and experiments are carried out in close collaboration so that knowledge gained from one can be fed back to the other. Experimental results help to verify and improve models, while modelling aids the interpretation of experiments and allows for more efficient experimental resource targeting.
Looking forward: areas under investigation
- Observing pore geometry effects on fluid flow
- Understanding fundamental wettability influences
- Identifying areas for pore-network modelling work flow refinement
- Measuring cap rock permeability and capillary entry pressure parameters, vital to determining the storage capacity of a candidate CCS reservoir.