Burts Bees do a pore minimising product which I have used and it worked for me. It's like a green powder that you mix with a bit of water and make a paste and put it on your face
A friend of mine has very oily skin and open pores and she swears by the pore minimising products from Clinique. There are about three different products that do different things so you would need to ask the consultant on their counter which one would be best for you. They might even have a sample you could try.