Division Step 3.1: Characterisation of the storage dynamic behaviour

At least the following factors shall be considered:

1. (a)

   possible injection rates and CO₂ stream properties;

2. (b)

   the efficacy of coupled process modelling (that is, the way various single effects in the simulator(s) interact);

3. (c)

   reactive processes (that is, the way reactions of the injected CO₂ with in situ minerals feedback in the model);

4. (d)

   the reservoir simulator used (multiple simulations may be required in order to validate certain findings);

5. (e)

   short and long-term simulations (to establish CO₂ fate and behaviour over decades and millennia, including the rate of dissolution of CO₂ in water).

The dynamic modelling shall provide insight into:

1. (f)

   pressure and temperature of the storage formation as a function of injection rate and accumulative injection amount over time;

2. (g)

   areal and vertical extent of CO₂ vs time;

3. (h)

   the nature of CO₂ flow in the reservoir, including phase behaviour;

4. (i)

   CO₂ trapping mechanisms and rates (including spill points and lateral and vertical seals);

5. (j)

   secondary containment systems in the overall storage complex;

6. (k)

   storage capacity and pressure gradients in the storage site;

7. (l)

   the risk of fracturing the storage formation(s) and caprock;

8. (m)

   the risk of CO₂ entry into the caprock;

9. (n)

   the risk of leakage from the storage site (for example, through abandoned or inadequately sealed wells);

10. (o)

    the rate of migration (in open-ended reservoirs);

11. (p)

    fracture sealing rates;

12. (q)

    changes in formation(s) fluid chemistry and subsequent reactions (for example, pH change, mineral formation) and inclusion of reactive modelling to assess affects;

13. (r)

    displacement of formation fluids;

14. (s)

    increased seismicity and elevation at surface level.