It does not take long to realize that there are more varied predictions on how much Natural Gas this country has, than there are flavors in your local store’s Ice Cream freezer. And, unlike that Ice-Cream, many of the natural gas numbers leave a sour taste in the mouth. Which numbers are correct, which are biased towards an agenda, and which are just plain old pie in the sky – (a-la-mode)?
Now, I am not a geologist so I cannot offer my own independent conclusions, although that does not seem to inhibit many others. What I can do, is to look at those numbers, compare them, and attempt to derive some sensible compromises based on reality, technical awareness, and just plain common sense.
First, lets look at the numbers reported by what are considered by most to be credible and reliable sources. Unlike some, these sources also have facts and figures to back up their analysis.
The United States Geological Survey in their latest report ( Dec 2008) says we have 742 Trillion cubic feet of proved conventional reserves, 378 Trillion Cubic feet of Unproved reserves, and 743 Trillion Cubic Feet of technically recoverable Unconventional resources (Shale and tight gas).
The Energy Information Administration in Jan 2007 puts US total recoverable conventional reserves at 211 proved and 373 unproved, and technically recoverable unconventional reserves (Proved and unproved) at 1,366 Trillion Cubic feet. Ref: http://www.eia.doe.gov/oiaf/aeo/assumption/pdf/oil_gas.pdf
Already we have some serious disagreement, although both sources agree on Unproved Conventional gas. The difference in the unconventional reserves likely centers around the definition of “Technically recoverable”.The big difference comes in the proven reserves. For some reason the EIA comes up with a very low figure for this, (I did the math 3 times). Yet, both sources add up to roughly the same total of 1,800 Trillion Cubic feet of reserves.
Now, lets turn to the Natural Gas Association. First of all, they agree with me that there is a wide disparity in these assessments. I feel so good! They base their own assessment on EIA data as above with total proven reserves at 211 Trillion Cubic Feet, and a total of 1,536 Trillion Cubic feet of unproven reserves.
http://www.naturalgas.org/overview/resources.asp (Very useful page!).
OK. The above references, ignoring what they consider to be technically recoverable, all predicate that we have a total of about 1,800 Trillion Cubic Feet of Natural gas reserves in the US. Now, I could fill a few pages with references to other reports that “grow” this estimate in leaps and bounds. It all culminated for me in a purported report from JP Morgan Chase that our reserves are NOW 8,000 Trillion Cubic Feet. I have not been able to find the actual report, only references to it. It does strike me that many of these inflated numbers are coming, not from geologists, or even energy companies, but from institutions with a financial stake in the trading of Natural Gas. Hmmmm.
I would like to point out also, that there is wide disparity on how much of that gas can be recovered. Certainly not all. According to the Natural Gas association, about 10% of the unconventional. Many sources put it closer to 30 percent. So far shale gas production in the Barnett shale has not lived up to expectations, and they are recovering about maybe 35% of what they thought they would. http://www.aspousa.org/index.php/2009/08/lessons-from-the-barnett-shale-suggest-caution-in-other-shale-plays/
One final issue I would like to address. A common talking point is how many years this supply of Natural Gas will last us. First some baseline numbers. We used 22 Trillion Cubic Feet of Natural Gas last year. That is 1.8 TCF per month, or 60 Billion Cubic Feet a Day! In the same month we will use about 11 Billion gallons of gasoline, 5 billion gallons of diesel fuel and 342 Million-Megawatt hours of electricity.
Well, if we change nothing, and manage to recover all 1,800 TCF of our natural gas, we are good for 81 years. If we manage to only recover 35%, then about 28 years worth.
But, what if we try to replace our gasoline use with natural gas? That 11 Billion Gallons of gasoline a month is about 1,364 trillion BTUs. Equivalent to 1.3 trillion Cubic Feet of Natural Gas, increasing our consumption by 72%. If we add in the diesel, that would equal .65 Trillion more Cubic feet. So replacing our transportation fuel would more than double our consumption of Natural Gas, and reduce our remaining supply to 14 or 40 years, depending on your optimism level. http://www.theoildrum.com/node/5615.
Let’s replace electricity from coal instead. Coal supplies 48% of our electricity, or 164 Million-Megawatt hours a month. Each one has 3.414 BTUs of energy. So, that is 560 Trillion BTU’s. (I checked the decimal point). It would require .6 trillion Cubic Feet of Natural gas to replace our coal. About a 33% increase, assuming the power plant efficiency is the same – it is close. That would make our natural gas last anywhere from 19 years to 54 years, again depending on how much natural gas we can actually recover.
Finally, I would recommend reading this report on The Oil Drum. It addresses some of these points, and also makes the point that the whole natural gas reserves picture is steeped in unfounded numbers and hype.
As for me, I think I will have some Ice Cream.