Table I. Crude oil characteristics.

	Biodegraded Oils	Unaltered 0ils

Reservoirs Age Depth, TVD API gravity Sulfur, % Vanadium, PPM Pristane/phytane % Saturates/ % aromatics Carbon isotopes {Sats.} Sulfur isotopes	GA,HB Trim - A 4200-4800 25-29 1.1 - 1.5 9 -17 1.50 48/40 -27.3 -6.O	KE,LF,OI Ang - B 6600-7400 31-38 0.5 - 1 .1 1 -10 1.20 57/32 -27.5 -6.4