I was wondering: is there a sample of an oil barrel in the VDL (maybe in different sizes)? If not, is there another instrument in VDL that has a similar sound?

Eric offers some good suggestions here. Also, you might try using the propane tank, then tuning it down several steps to give it a deeper, oil barrel sound.

What about the trash can sounds? Or even messing with the steel drum sounds to get the right sound you are looking for.

Without it being here in front of me, might there be something in the Metal Combo you could use?