Delving a bit more into the Marcellus shale gas reserves issue, previously discussed, it seems there is some controversy as to how much gas is there, and how expensive it will be to get it out.

A website called Energy and Capital had a post about a year ago here, saying

Back in 2002, the United States Geological Survey (USGS) reported that only about 1.9 trillion cubic feet of natural gas was technically recoverable.

Well, things are about to change.

In December, 2007, two professors, Terry Engelder and Gary Lash, reported that the Marcellus shales could hold 167 trillion cubic feet of gas. And that was based on their conservative estimates. Their higher estimates suggested the formation could be as much as 500 trillion cubic feet. If you take into account a 10% recoverability factor, that comes out to almost 20 trillion cubic feet.

The author goes on to note that drilling firms that have been successfully using horizontal drilling methods to get gas out of a formation called the Barnett shale in the Texas region, may well move into the Marcellus shale, and that these would be good investment plays.

There are some interesting factors to consider here. How good is the academic estimate of the amount of gas in the Marcellus shale? What do such estimates depend upon, and what sorts of investigations are appropriate to confirm them? Maybe some of our friends at Cornell in geophysics can have a look. Meantime, I’ll dig out some of the citations.

The firms working in Texas may have also to contend with very different conditions in the Marcellus shale than in the Barnett. At least parts of the Marcellus shale area were affected by glaciation, for example. Are there any geomorphologists out there who can comment?