The discussion title is from an article by Arthur Berman who is Contributing Editor for "WorldOil.com - The oilfield information source". A link to his article is contained in his response to our discussion on decline curves. I have excerpted his post to begin this discussion as I think his professional views are most informative and should be of interest to our members. Mr. Berman has granted me his permission to repost his comments. Thank you, Arthur.
Reply by Arthur Berman 3 hours ago
Skip,
All shales are not equal. The Haynesville Shale is overpressured and, therefore, less brittle than the Barnett, so fracture stimulation is not as effective. It is also much deeper, so there are more problems reaching sufficient pressure with pumps, etc. to create a good fracture stimulation. Also because it is deeper, any fracture that is created is less likely to remain open.
For a fuller discussion of Haynesville vs. Barnett, see my September column in World Oil:
http://worldoil.com/magazine/MAGAZINE_DETAIL.asp?ART_ID=3640&MO... .
The flatter "tail" of the decline curve is not something that I see much value in, since it is highly interpretive at this early stage in Haynesville production history. Also, monthly production volumes in the flat portions of hyperboloic decline curves rarely generate enough revenue to cover lease operating expenses, so much of the reserves from this phase of a decline curve are not commercial, though technically recoverable.
When I do a decline analysis, I usually figure something like $5,000-10,000 month are necessary for lease operating cost. Assuming that current gas prices are $7.00/Mcf and about $1.00/Mcf of that goes for midstream costs, and another $1.00 or more goes to pay G&A costs, that means that the economic limit of a well is between 1-2 MMcf/month. That doesn't include taxes and royalty which is perhaps another $2.00/Mcf, so really the economic limit of a well is 1.75-3 MMcf/month.
All the best,
AEB