The recent interest is largely driven by field observations which suggest that the saturation pressure in tight formations may change dramatically. Therefore, it is expected that the extremely low permeable Lower Cretaceous rock may influence the phase behaviour of the reservoir fluid.
The degree of influence needs to be estimated with a theoretical model that can be experimentally validated.
We propose here a modelling study of the effect of tight rock on phase behaviour that will be validated experimentally in parallel. We will use the modelling and simulation tools developed in a recent shale project with ConocoPhillips to analyse especially how capillary pressure will change the phase equilibrium.
With the modelling and simulation tools, we will perform calculations specifically for the Lower Cretaceous reservoirs of interest by including their rock properties and pore characteristics into the calculation. We will also simulate the depletion production process from Lower Cretaceous reservoir rock, which can reveal the interplay between changed phase behavior and fluid flow in such a production process.
The simulation can be made both for core plugs and for reservoirs. The former is useful for interpreting laboratory depletion tests in tight rocks and the latter is useful for interpreting the field scale production.
The project is funded by the Danish Hydrocarbon Research and Technology Centre.