Replies to This Discussion

Permalink Reply by Aubrey C. Sanders, Jr. on May 13, 2010 at 10:49

Tony,

The two wells you mentioned are in the same unit, but probably not on same lease. Typically there may be several leases within any given unit. You can tell they are in same unit by fact they are both in SUI. This is the unit designation. Well # 240888 is an alternate to 209254. Alternate unit wells are very common because, rarely, if ever, will the original unit well be able to effeciently drain a unit. Through reservoir engineering studies conclusions will be drawn as to need for and placement of alternate unit wells.

It appears to me that well number 209254 was originally a lemon, but they made lemonade from it. Smackover completion was the lemon, but Haynesville sand and Cotton valley turned out very well.

As to why they waited so long to drill last well I am not sure. Perhaps re-interpretation of additional geologic data spurred drilling of latest well. Maybe competition from competiors on adjacent leases and drilling new well was protective move to avoid drainage.. Maybe just the fact that the
unit was being held by production influenced decision.

The changes in the older well were simply made to enhance production by going to different formation. Very common when deeper formations are depleted.

Permalink Reply by tony allen on May 13, 2010 at 14:43

Thanks for the explanation Mr. Sanders,I think I understand the alt wells now.Sonris show wells 237333 and 237867 by petrochem have exactly the same production numbers,is that a combined production of the 2 wells ?It seems that Petrochem did these wells within 6 mos of each other,and they did the same for wells 236447 &237577.I guess the O&G can drill multiple alts without violating the 160 spacing rules.Do you think they moved so fast to protect from drainage from the Questar wells?Thanks again for sharing your experience with those who have none! .