by rockdoc123 » Sat 25 May 2013, 11:20:05
$this->bbcode_second_pass_quote('', 'R')ockdoc, whose data? The first chart comes from 6 or 7 wells. Do these 6 or 7 wells represent a larger trend? If so, why? How is the data better than that referenced by Berman and Likvern?
It's plotted data from individual well production from the operators in the play. I used to have access to priority data from one of the major consulting firms. That firm tries to differentiate wells into like candidates (i.e. similar completion length, number of fracs etc)
The reason why this is better information to look at than Bermans in my opinion is because (and I think I've said this on a couple of threads) he gets his data from publications that do not discriminate between age, horizontal versus vertical, short lateral versus long reach horizontals, completion type, completion length, propant used or not...etc etc. Statistics is a great thing to us in any argument as long as you are not lumping apples and oranges and grapefruits together in order to surmise something about bananas.
At one point I did mention a statistical study that is a bit different and actually has some validity.
Swindell, G, 2012, Eagle Ford Shale - An early look at ultimate recovery. SPE 158207
in this study efforts were made to discriminate between various elements and as one would guess there is a difference between the more modern wells which are longer horizontals, have larger and more numerous fracs and the older wells, some of which aren't even horizontal. This is an important point to my mind. That is why, I believe, it is more instructive to look at individual wells or groups of wells of the best operators. Because of the nature of the oil and gas business in the US and Canada there are a lot of small operators who are hitting well above their weight when it comes to shale gas/oil developments and often their wells are not descriptive of what the shale could produce if properly drilled and completed. Looking at the best operators and their well performance should instruct better as to what the shales can do under the right technological applications.
Of course there is still the issue regarding sweet spots within the shales. The Swindell study addresses this for the Eagle Ford by looking at EUR on a county by county basis. Interestingly enough if you correct his BOE conversion calculation (he uses 20:1 as he believes it reflects price but the industry uses 6:1 as its standard unrelated to price) the EURs across the play are not all that much different, averaging out close to 400 MBOE/well.