Boundary conditions

Hi, I am modeling the injection of fluid into a porous domain through a fault. I have a created multiple zones for the domain(sand, shale and fault) and put an injection well at bottom end of the fault that cuts through the horizontal sand and shale layers. I want to model the fluid injection such that there is flow of the fluid from the fault zone into horizontal layers surrounding the fault and liberation of remaining fluid from the top. So far, all my fluid is getting collected at the top and saturation at the top of the fault increases significantly. Is it due to having a no flow boundary at the top? I haven't specified any boundary condition, so I'm not sure what I can do to make the flow liberate from the top. 

Can anyone suggest to me what changes I need to make?

Thanks,

Sulav