Not necessarily.
If it's half, it may be worthwhile on an energy basis in a narrowly defined sense. But there are far-reaching secondary energy costs beyond this explicit accounting. How do you account for the fuel burned in the jetski that your combine operator uses in his free time, or the cost of forging the steel that went into his combine blades? We live in a global economy and in this sort of analysis, there are probably hidden emissions not noted in the study that make 2:1 EROI insufficient.
There are non-EROI issues as well. What happens if we devote all our land to biofuel production? People starve. What happens if we devote all our land to 10:1 biofuel production and it doesn't cover 1% of current demand?
We have crops with higher Energy Return on Investment, just none (so far) that are economical to produce in Iowa in order to win the Iowa caucus.
Brazillian sugarcane ethanol is perhaps 5:1.
Daytime, immediate-use solar is something like 30:1. Less when you factor in batteries.
Wind turbines around 20:1.
Hydropower is maybe 100:1.
Oil varies enormously. Used to be, sweet light Saudi crude from the Ghawar field might break 100:1. Most fields globally more like 10:1-20:1. Alberta heavy oil sands are something like 5:1. If you dip all the way down into ultraheavy kerogen fuels, solid at room temperature and demanding lots of processing, there are certainly deposits that are less than 1:1.
https://en.wikipedia.org/wiki/Energy_return_on_investment
There was a bit of an obsession in the mid 2000's with the concept of a global "peak oil" production, limited by supply-side constraints involving all the low-hanging fruit effectively being picked. While this is often dismissed as neo-malthusianism catastrophism, most of the ideas involved are unscheduled eventualities rather than some defined apocalypse. It introduced a lot of people too young for the 1970's OPEC embargo to the concept of energy scarcity, and effectively ironed out a great deal of the discourse using a fairly active forum.
http://theoildrum.com/node/9249
The major errors of that community's consensus were:
A) The particular shape of the Hubbard Peak bell curve is somebody's fit, not related to fundamentals, and extrapolating sigmoid / logistic curves have both huge error bars when the reasoning is sound, and little merit if the reasoning is not fundamentally sound. You simply can't predict a peak well in advance based on inflection points of this wide of a variety of sources, central limit theorem be damned.
B) Natural resource reserve estimates are both highly subjective and something that suffers from game-theoretic problems. If a speculator 'knows' that the ridge on the horizon is probably full of gold, but has an incentive to work the claim he already started a few miles away, he has no reason to report it. The same applies to countries and companies. Honest reserves estimates are also always quoted in terms of "Economically extractable at current prices", but prices can change and dramatically shift the number.
C) While the underlying fracking and injection technologies to expand the horizons of what constitutes an extractable reserve date to the 60's, they were not ubiquitous or as readily controllable until recently.
D) There is more than enough long-tail low-payoff hydrocarbon fuel out there for us to boil the planet in a CO2 oven, unfortunately.