The present cases will demonstrate CO2 injection into a saline aquifer. Note that the set up of the flow models used to simulate this type of CO2 injection will differ from the ones used to simulate CO2 injection in depleted gas reservoir. The simulations for the cases presented here will consider the following 3 stages with a total simulation time of 50 years and the following set up:

 

1.Initialisation:

i.A hydrostatic pressure distribution

ii.Surface temperature of 10 ºC with a thermal gradient of 0.035 ºC / m

iii.Uniaxial stress burial conditions derived from the sediment column weight

 

2.Injection:

i.Injection of CO2 will be simulated from t=1 year to t= 21 years (20 years of injection)

ii.Injection via a well located in a corner of the reservoir from depth of 1370 m to 1390 m

iii.An injection target gas surface volume rate of 1.0 Mt/year (0.25 Mt/year for a quarter-model)

 

3.Post-Injection:

i.After injection the well is closed and the simulation carries on for a further 29.5 years after well closure

 

 

Two cases will be considered:

 

▪Case01a: Isothermal case (temperature is prescribed and is constant throughout the simulation)

 

▪Case01b: Transient thermal case (Pflotran-OGS will solve the thermal field)

 

Note that the folder structure required to run ParaGeo-Pflotran-OGS coupled simulations as well as the different results being output will be described in detail in Case01a and may be omitted in the cases that follow.