Cause of temperature jump in high-res model

[Mai MRST]

Hello MRST team,

I'm running geothermal models and noticed that in a high-res model with 10 m cubic cells, the temperature within injection well rises by almost 10 degrees compared to a low-res model with 20 m cubic cells.

What could be the cause of this temperature elevation? Is this a result of fluid compressibility? We have the same result with an incompressible fluid. Is the enthalpy relationship to pressure independent to the fluid compressibility in MRST?

Does MRST incorporate any energy/enthalpy terms for frictional heating during reservoir flow?

Best,

Mai