Dear Rockman;
That was a good reply thanks for taking the time
k – Haven’t been able to follow the entire conversation. But note on your map that the red dotes are wells that tested between 0 and 2 mmcf/d. In reality there are very few if any “dry holes” in the trend. But there may be a high percentage that test a non-commercial flow rate of NG and are thus never produced.
You and Rock Doc are right about this. "It was something I saw on the internet.", When I chased down the source,I would say this is more correct.
Not sure about the cap rock portion of the conversation. Typically there’s no cap rock or top seal with respect to the fractured shale plays. All the NG that is produced from such formations is that which has been taped in the naturally occurring fractures. Those fracture don’t extend infinitely upward. Where they stop vertically is where that production ceases.
A lot of the confusion is that I get information from a lot of sources and they differ in important ways. The cap rock thing I got from a geologist friend of mine. Rock Doc and you seem to differ in the process of fracking, although he seems to have changed his mind. Anyway, what I think you call fractures, somebody else might call a flaw. A flaw would be a place in the rock which has no tensile strength. Anyway, the fluid should flow immediately into these flaws. I would expect that the flaws are then extended in fracking, since as I understand it they listen for the extension with (micro seismic) microphones. Since these cracks are extended it doesn't seem likely that there is a lot of gas trapped in them. When the fluid is removed they remain open due to the propant. I think what most frackers think is that the gas is then emitted from the very high surface area of the fractures. The hyperbolic curve they expect comes from Darcy's (him again) law. It is well known that diffusion dominated processes, and Darcy's law would have the same math, have a square root of time dependence. Your model would not have that dependence, since I assume from your model that these flaws are just accessing pores in the rock.
Where you, Rockdoc, and John differ with me, and I think a lot of other people is that we think that the rock responds plastically to the deformation of fracking, by extending other preexisting flaws away from the frack. If this is enough to provide a percolation path to an aquifer, who knows, but like you said it is possible. Also if there is an increase in contamination near these it may be due to plastic processes far away from the aquifer, allowing nearer things.
Saying there was methane contamination in the water after Cabot drilled doesn’t prove the water wasn’t contaminated before they drilled
To me when somebody says something changed, something changed. I realize that there is a logical flaw there, so it's not proof, but I take it seriously.
k - I can't remember if I've made this point to you before but I do have a dog in the fight over shale frac'ng. A very big dog, in fact: I would be very pleased if they proved frac'ng always damaged fresh water aquifers and was banned everywhere including Texas. It also wouldn't hurt my feelings if the banned the import of all Canadian oil.
Um, I thought I had a dog in this fight also. And also on both sides, since I own land above the Marcellus shale, and I though I would have a decision to make, or have one made for me. I am kind of doubting that now since, the USGS downgraded the western part of the field, and it turns out that I am between the dry gas and wet gas regions,and that video I posted. It seems pretty clear to me that by the time the juggernaut gets to Allegany count if it does all these issues will be more clear.