Roger,

Thx for responding. Ok, quoting you, "The economic quality of that tankful depends on the amount of economic effort that was required to extract the oil,...". Emphasis added. Economics has nothing to do with EROEI.

And, "If for example it took 10 labor hours to produce a tankful of gas from conventional oil compared to 30 labor hours to produce a tankful of gas from oil shale, then clearly the gas produced from conventional oil is superior." It may be superior (and, no, differential labor hours is not common sense) but that isn't what EROEI is about. It is how much energy is required to produce so many joules compared to how many joules you had to expend to get them. And, BTW, I've done energy balances for chemical plants so I am not unaware of how to do them.

Let's look at on-shore and ultra-deep water drilling. It may take more "labor hours" drilling on-shore but the infrastructure for deep water drilling is massive, e.g., it requires horrendous amounts of energy before drilling even begins! Yet, on a bpd basis, the off-shore field could look excellent on the basis of "labor hours" alone.

I am totally lost by your last statement, "Energy balance calculations just account for the excess resource costs due to the consumption energy during the production of fuel." Excuse me? So, drilling, et.al., don't count when it comes to EROEI, just the energy used by a refinery? Now, I may have misinterpreted this so maybe you want to clearify it.

Todd

As an aside, the Yahoo Energy Resources forum has beaten EROEI into the ground for several years but has yet to find common ground.