thanks
your calculations indicate that there is no precise answer for this question - but we're in the ballpark.
13,800 hours of manual labor at $20 per hour is $267,600 per barrel.

And I could make the argument (strongly) that the energy quality of oil is higher than human labor...;)

Crude at $97.75 today a bargain!!!!

I had always heard about 75W output on a fairly continuous basis for a fairly fit person, but wouldn't be surprised if in reality it is more like 50W when average fitness is considered and the work is stretched over 8 hours, day after day, month after month...etc. So the 25,000 hour figure not off the mark either perhaps, though I don't know enough to argue about it.

The numbers I have are a gallon of crude is about 138,000 BTU, and a gallon of gasoline is about 125,000 BTU. The standard figure for boe is given as 5.8 million BTU.

Using these numbers, I get about 16,600 hours. 100W is perhaps a little high for sustained effort, usual figure is 0.1 HP, about 75W. This gives nearer 23,000 hours manual labor.

33 kwh is gross chemical potential energy, but given that we are mostly concerned about mechanical uses for oil should we not be doing somthing like this?:

first subtract 10% for energy cost of the oil production i.e. assume that EROEI on oil is about 10:1 right now, that gives us 29.7 kwh / gal

then assume 2/3 will be lost when converting it to mechanical by running an engine connected to a machine, so we then have 9.89 kwh / gal

So a gallon is more like 9.89 / 0.8 * 8 = 98.91 person hours of labor.

X 42 = 4,153 hours of manual labor per bbl (that would be 1 person year at 6 days a week 13 1/4 hours a day, which sounds like a rough number estimate for a third world sweatshop).

Lets assume we can hire manual labor "somewhere" for 20 cents an hour (1/3 of the worlds population earns less than $2 per day according to the UN) then the manual labor substitution cost of the bbl becomes something like $830 per bbl.

Is this the valid measure? This talk of "slave labor equivalents"? Consider: If there is a half-ton rock, I might require ten slaves to move it (figuring each slave capable of lifting 100 lbs.). But I have technology: a long lever, a wheeled cart. Now, instead of ten slaves, I can move the rock myself (given certain assumptions such as a fulcrum for the lever and cart-friendly terrain - but those assumptions aren't unreasonable for a broad range of situations). Nor do I need to eat ten times my normal meals for the day to have energy for the lever and cart.

Since much of our technology is of the lever or cart type, rather than the brute strength type, this whole "slave equivalence" metaphor is severely misleading. It makes for a nice rhetorical flourish, but misrepresents our reality. It treats machines as primarily energy-consumers, whereas they achieve their primary value via design - as levers and carts do - with energy inputs being a real but secondary, and not tightly-correlated part of any equation accurately describing their place in our economy.

Comparing oil to manual labour may provide a sense of scale to the energy in a barrel of oil but it ignores the sheer versatility of oil.

No matter how many human labourers I have, I will never be able to get them to move me along at 60 miles per hour without ever complaining or getting tired.

Human labour can't be converted into lubricants, chemicals, medicines, ashphalt, plastics etc., etc.

What a miracle oil is ? $ 100 a barrel is a bargain.

From "Food, Energy, and Society" by Pimentel, pg. 13. Gasoline is 20% efficient in converting to work in a mechanical engine, 8.8 kWh. A horse working for ten hours at maximum capacity yields 7.5 kWh. Man can work at 0.1 HP or 0.075 kW per hour. 117 hours of Man work done by 1 gallon.

See http://greatchange.org/bb-answer2.html for a tentative resolution of $146.00 as the value of gasoline per gallon, considering the energy cost of machinery and the need to do more work as value than what simply pays for the fuel.