try fiddling with the viscosity setting... 0 makes it flow like water 1 makes it flow like tar...

and/or

also the boyancy on the density needs to be really low as well to get a very subtle movement on the fluids and as you know boyancy makes the fluids go up or down 1 being up -1 being down and 0 it doesn't go anywhere at all and the only thing driving the fluids IF ANYTHING at all is the gravity...

you can actually keyframe these settings too