In order to run some numerical simulations, I would like to know some rough values (estimates) of the velocity at which the crude oil flows through the rock or soil matrix from which it is extracted. I found lots of data about production rates (bpd), which is the main parameter of interest from the engineering point of view, but so far, nothing about this technical aspect. One last thing, I am an outsider (civil engineer and applied mathematician), not an specialist.
Think in order of magnitude terms of inter-well spacing (500 metres in an offshore waterflood?) divided by water breakthrough time (say, 3 years). 500m/1000 days = 0.5 metres per day. Yes, I know a saturation contour isn't a fluid particle (phase vs. group velocity), but the relevant multiplier will be of order unity.
If you want particle velocity, another approach is to do the calculation (flowrate * formation volume factor) / (linear dimension * net thickness * porosity). Say (100Mb/d * 1.3)/(10km*100m*0.15) = 0.14 metres per day, so same close order of magnitude. Of course things will speed up when you get into convergent flow near the wells.
Are you using a commercial reservoir simulator? They don't normally concern themselves with fluid velocities, at least not in terms of what goes in and out of the code.