The surname "van Gulik" is quite common in the Netherlands. The name literally translates from Dutch into "from Gulik". It appears that the location referred to is the Duchy of Jülich
The name has been modified over time from an original "van Jülich" to it's present variants like: van Gulik, Van Gulick, Van de(r) Gulik, Guliks, Gulickx, Gulikers, and Jülicher.
A reference on Wikipedia is available here: