JT Heat exchange in the cell containing well (using ECO2N)
In a non-isothermal run with gas (CO2) injection into an aquifer conditioned within supercritical domain of CO2, you expect some heating from compression and some cooling from expansion. Is it right to assume that compression happens usually inside the cell containing well and from there beyond, it will be some expansions as flux area stats to expand? I wanted to find out whether both positive and negative contribution to heat find place when we use either "well" or "source" as the mean of injection? Is it functioning In the same way in a T2well-ECO2N configuration where the wellbore cells are open?
Comments are welcome.
if I properly understood your question, in T2Well-ECO2N (as in all TOUGH2/3 simulators) there are no specific options to model JT effects. Cooling or heating driven by pressure changes simply derive from the dependency of fluid mixture enthalpy from P. According to P changes, you simply have a change in mixture enthalpy and this may produce a change in fluid T (buffered by the rock heat capacity) .
This is accounted for by the simulator independently on the option you use to simulate the injection of the gas.
Usually a P increase/decrease produces a cooling/heating, but it depends on the fluid mixture and (P,T) conditions. For instance, at high P the JT coefficient may become negative and the P effect is reversed. Below an example of JT coefficient computed as function of P (200-1000 bar-a) at 3 different T (30, 60 and 100°C) for an injection gas mixture of hydrocarbons (mainly methane) and acid gases ( H2S + CO2). At P between 200 and about 480 bar-a the JT coefficient becomes negative.
Appreciate your rapid help here, as usual.
I am aware of the +/- effects upon "where" in the envelope one might be. But I got a better understanding of sole P and delta-H dependency now, thank you indeed.