I think the weakness is directly related to the over all market. The DOW is at a critical juncture here, if it doesn't bounce soon we may be in for a very bearish winter in the markets I'm afraid.
The so called fiscal cliff and diminishing profits and outlook from many of the majors is not boding well in the near term. The oil price in most cases is related to economic activity (sometimes supply issues) so prices could drift lower.
PBN costs are low and production is ramping up so I think they will fare better than most in a low oil price environment. Their cash flow should support the dividend, which in turn should support the share price as well.
Of all the companies out there right now, PBN looks to be the best investment during a downturn IMO.