If Washington is preparing for another SPR release, it won't do it during the GOP convention and give the opposing party a political topic to address. But it will take action soon after it's over, as the window is only briefly open. And the best way to play it is with crack spreads, actually buying gasoline against the sale of crude oil; however, these are very sensitive and difficult trades to time. Another option, and the one I recommend, is playing two refiners that always seem to be at the front of the line when cheap SPR barrels are made available: Valero (VLO - Get Report) and Hess (HES - Get Report).
I already am long Valero against a short of Tesoro (TSO - Get Report) so I will be less likely to load up further on this stock. But Hess, which has done nothing in the big crude rally (the shares are currently hanging around $50), looks like a good short-term punt. Plus, if the SPR release doesn't come, you've lost nothing.
Trading by trying to guess at government action isn't usually a winner's game, but this looks like a reasonable shot to take for a short time. Wait until the middle of next week and see if I'm right.