I'm looking to make share investment in oil service companies. Anyone else have investment in this sector? Tips? Opinions?

I'm currently looking at Transocean, PGS and Petrofac.

Well, as a finite resource in scarce supply the future looks grim.
However the price will sky rocket up until that point, so profits will come.

How many new oil fields being discovered ? What volume of shares are being traded ? Any pre-IPO companies to be had with fat post-IPO profits ?

unfortunately for us, the market has already priced in whatever tips and information we can offer. where these stocks will go next is anybody's guess.