constraints in well bore conditions

Hello all!
I am building a 3D model, and I use well bore conditions. If I want to define minimum height constraint, have I to define one value of minimum hight at all slices or a different one at each slice ??

You should define the same value for all slices. As active constraints may convert the well bc into a head bc, you'd have a mixture of well and head bcs in the different slices if you would put different constraint values. Be careful with the minimum head constraint: If the water table falls lower than the minimum head due to external effects like neighboring wells, you'll get infiltration at the well. In such a case, it would be better to use a head condition (value = minimum head) in combination with a minimum flux constraint to specify the maximum pumping rate.