You may be having a legit but, and if so I apologize, but there is a max limit to the length of your oil line (6-7 patches). The southern one you need to direct the line THROUGH the fence, because the fire will chain through it even if you can't walk through. The oil thing I didn't know, but map chat helped clarify that. However, I still was having trouble getting the oil down -- the workaround I found was to mount up and down, and then it would work again. But back in LS3E5 at the volcano, I never had this problem, so... I'm assuming something is wrong here with the oil mechanics in general. I actually tried the fence, and it never went through (twice when I'd TEST it it'd work, but never a straight line...), and managed to stretch out 7 patches around the corner to get it. Still terribly aggravating. Not to mention, the meta event splattered oil elementals everywhere at one point...