Properties of Athabasca Bitumen and Boscan Ultra-heavy

I found an interesting table in the text 'Hydrocracking Heavy Hydrocarbon Feedstocks...', J.F. Kril & M. Ternan, 'Catalysis on the Energy Scene', Elsevier (Amsterdam) 1984.

Property	Athabasca Bitumen	Boscan Heavy Oil
Relative Density (15 °C)	1.009	1.016
Pitch 524 °C (wt %)	51.5	66.7
Conradson Carbon Residue (wt %)	13.3	16.7
Pentane insolubles (wt %)	16	22
Tolune insolubles (wt %)	0.7	0.1
Ash (wt %)	0.6	0.2
Components
Carbon (wt %)	83.4	82.4
Hydrogen (wt %)	10.5	10.4
Sulphur (wt %)	4.5	5.7
Oxygen (wt %)	1.0	0.5
Nitrogen (wt %)	0.4	0.8
Iron (ppm)	358	23
Vanadium (ppm)	213	1174
Nickel (ppm)	67	114

It seems that the Venezulian ultra-heavy oil from Boscan is in many ways actually worse than Alberta bitumen. I didn't know this; I assumed that the investment climate in Venezula was driving the preferrential development of Alberta tar sands.