These are the usual culprits:
1) Too much priming sugar causing overcarbonation.
2) Incomplete mixing of the priming sugar, causing some bottles to be over-carbed and others under-carbed.
3) Too much trub/particles in the bottled beer creating nucleation sites for CO2, causing it to create excess bubbles.
4) Beer too warm.
I'd try opening them when they've been in the fridge for a few days to make sure everything has settled to the bottom of the bottle and the CO2 is fully dissolved. Then just slightly pry up the edge of the cap to let some of the pressure out. Try this a few times before opening it all the way. If there isn't a whole lot of pressure in there, and it just foams and foams, then it's probably a bottle infection.
Just be careful - overcarbonated bottles can be pretty dangerous.