Hello!
I have been doing the Berkeley Method for two years with wood chips, here's what to do:
Wood chips have a C:N of 226:1 but really this is misleading because although you will have compost after your 18 days of turning turning and more turning, your pile will still be full of wood chips. The reason for this is due to the fact that only the outer layer of the woodchip is consumed by your thermophilic bacteria, these little guys are amazing but they can't consume whole chips in only 18 days sadly (this was something I was very puzzled about when I first started my Berkley Method with Woodchips adventure. The true C:N ratio of a woodchip is actually more like 678:1!
So I sift or Tremmel out the chips from the compost and reuse them until they are no longer. Most of the time it takes three or four trips through in order to completely compost a chip. It's the lignin in the wood that takes so long to decay, the stuff which keeps trees upright!
At first I thought this was lame having to sift out my chips but then I realized that I didn't need to keep finding chips as often so there's an upside for sure.
Check out this compost Calculator from Washington State, it's the best one I have found for sure.
http://www.klickitatcounty.org/solidwaste/fileshtml/organics/compostcalc.htm
Cheers,
Charlie