viscous pore/orifice flow

[MarkUMSU]

I'm looking for a guideline for approximating flow velocity through a pore or orifice for a given pressure and viscosity.

eg

My pressure differential is 13 kPa
The pore/orifice size is 0.5mm

Will a fluid with a viscosity of 1000cP be able to flow through this hole? What would be its velocity?

At what viscosity will there be no flow?

How concerned should I be about surface tension or other factors?

Thanks!