Negative discharge rate test

Hi, everyone

I try to use negative discharge at flowknots to simulate production well behavior in geothermal study. I notice that there are weird effective minimum principal stress distribution at production points so I do the simple simulation like below.

Model (with one joint as fracture):

Here is only neagative dishcharge rate (as production, -10 ton/hour) at center and no injection. There is positive stress (tension) near production points compared to initial condition. Greater stresses occur at distances from the production point.The larger eff. min. principal stresses are more likely caused by reduced pore pressure.

Initial stress:

End 30 days simulation:

My question is about why there is tensile stress occurs near production points and how to explain it ?