Those 10 years require the use of fracking, which is I think too bad for the environment, especially for a country as densely populated as Germany. The resources that don't require fracking are only enough for 1-2 years of consumption at current levels.
Germany just today cut a NatGas deal with Qatar to reduce RUS dependence [0]. They are certainly looking, as they should.
I'd say the biggest issue with the local fields is that they are likely undeveloped, and that takes time before the oil flows. Ironically, from what I've gathered watching the US fields, the fracking wells take less time to turn on/off vs the more ordinary wells.
If Germany can turn on any local wells, especially quickly, it should help significantly, since the big issue is to buy time - time to switch to new sources of NatGas/Oil, and time to replace sinks with renewables.
Also to consider is the relative harm from some short-term drilling & fracking, vs the damage if RUS has the funds to expand their aggression into more of the EU.
