[Graeme]

New, rigorous assessment of shale gas reserves forecasts reliable supply from Barnett Shale through

$this->bbcode_second_pass_quote('', 'T')he study, conducted by the Bureau of Economic Geology (BEG) at The University of Texas at Austin and funded by the Alfred P. Sloan Foundation, integrates engineering, geology and economics in a numerical model that allows for scenario testing based on many input parameters. In the base case, the study forecasts a cumulative 44 trillion cubic feet (TCF) of recoverable reserves from the Barnett, with annual production declining in a predictable curve from the current peak of 2 TCF per year to about 900 billion cubic feet (BCF) per year by 2030.

[Keith_McClary]

$this->bbcode_second_pass_quote('', 'W')hile the BEG model shows the correlation between price and production, it suggests that price sensitivity is not overly dramatic, at least in the early phase of a formation's development. This is because there are still many locations to drill in the better rock, explains Tinker, which is cost effective even at lower prices.
"Drilling in the better rock won't last forever," says Tinker, "but there are still a few more years of development remaining in the better rock quality areas."

[kuidaskassikaeb]

When I was reading the FAQs I saw this

Decline rate is the function of permeability, porosity and well depth and is proportional to 1/sqrt(Time) that is the square root of time. $this->bbcode_second_pass_quote('', 'D')ecline rate is the function of permeability, porosity and well depth and is proportional to 1/sqrt(Time).

[SamInNebraska]

Just as a practical aside, it strikes me that "new" and "rigorous" aren't the right words when talking about a particular producing formation which has been...producing...for 31 years. Call it a "gee we've manufactured wells all over this area and if we extrapolate the dregs that are left" its more like guessing at how much cereal is left in the box after you've eaten 3/4's of it...hell a chimpanzee could do that. Getting the answer right from the beginning, now THAT requires some talent. Like what Hubbert did.

[Buddy_J]

$this->bbcode_second_pass_quote('kuidaskassikaeb', '
')Bermans take on the Bakken shows the effect of assuming the decline rate on the ultimate recovery.
http://theseventhfold.files.wordpress.c ... r_2009.pdf

Since the takeaway on this paper seems to be that the Barnett will last forever, and the data in his paper is from the Barnett somebody got it wrong.

[dissident]

I don't see t^(-0.5) dependence in this graph from the same report that claims algebraic time dependence. All I see is exponential dependence. It's easy to tell by the fact that the tails for production initiated before 2010 are basically hitting the time axis over the range shown. With t^(-0.5) dependence all the tails would be extending past 2030.

Here is what t^(-0.5) dependence looks like:



(from this link)

[kuidaskassikaeb]

Mr. Dissident person:

Um I got the square root dependence out of the FAQs for the papers, which as far as I know are not available. Your graph is accurate, but exponentials actually look like the graph you gave also. You would have to put them next to each other to see the difference. In the long term one square root of T dependence is equivant to a B of 2. This according to Berman is outside the range of theory and must be wrong. But it is what you expect from diffusion and other processes where flow rate is propotional to pressure difference and removing the gas produces a depleted layer. To me this one half power thing was a big insight, in that despite reading the posts regularly on this site, I never quite figured where people disagreed.

I thought that Fraking was supposed to be a short term thing with a fast payback, that kind of died off quickly, but produced lots of gas. Now I find out that it is supposed to be a long term thing with a slow payback due to a long production tail. Also if these people are using a square root of T and the data has been exponential for another 4 years. Well that's not right.