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Permalink Reply by Les Bamburg on December 7, 2010 at 10:46

Abudu, in areas where both the Mid-Bossier Shale and Haynesville Shale are present, they are typically separated vertically by 600 - 800 ft. Operators are very skilled at controlling how far the fractures propagate vertically and keep them contained within the target formation. The fractures probably extend less than 300 ft horizontally from the lateral so hence the reason for needing ~ 80 acre spacing.

So an operator could drill two horizontal wells (one each in the Mid-Bossier Shale and Haynesville Shale) in almost the same vertical north-south plane and produce without any cross-drainage between the formations. This will also occur in some parts of the Marcellus Shale and Granite Wash because of stacked targets.

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Permalink Reply by adubu on December 7, 2010 at 10:56

Les B --Thanks for info-- another question pops up from your answer---what is the make up in the 600-800 ft vertically between the formations-- another type shale, sand or limestone or what? Do you mean the lateral legs could be in the same north-south horizontal plane just at different vertical depth as defind by depth of the bossier and haynesville?

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Permalink Reply by Les Bamburg on December 7, 2010 at 12:37

Adubu, I believe in most cases the two formations are separated by a low porosity section of the Bossier Shale (Lower Bossier Shale) that is non-commercial.

In theory horizontal lateral leg of a Mid-Bossier Shale well could be directly above the horizontal lateral leg of a Haynesville Shale well but in realilty the operator would likely have some at least some minimal amount (100 ft?) of horizontal separation.

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Permalink Reply by waltcop on December 7, 2010 at 11:28

Les,
Is the 600 - 800 ft formation that vertically separates the Mid-Bossier Shale and Haynesville Shale alway a non productive mineral formation (no Oil or Gas) or can there be pockets there as well? Just wondering since it is pockets of CV, and maybe other formations, in the same area as the MBS and HS which could allow for more than 16 wells per unit. Am I correct or is it just wishful thinking on my part.

Anyway, " Merry Christmas to one and all".

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Permalink Reply by Les Bamburg on December 7, 2010 at 12:40

Waltcop, normally it would just be a layer of non-commercial low porosity shale (Lower Bossier Shale) with no productive oil or gas.

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Permalink Reply by j garrett on December 7, 2010 at 16:53

The drainholes and fracs will bleed into each other, by design. The production from SL wells will be considered as coming from only one well, per the TX RRC field rules. The laterals can be no more than 300 ft apart.

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Permalink Reply by Les Bamburg on December 7, 2010 at 18:10

JG, the laterals for the two different stacked lateral wells would not be in communication. The intent is for each well to drain a separate formation interval (Haynesville Shale versus Mid-Bossier Shale).

The laterals can be no more than 300 ft apart in the horizontal direction but there is no limit in the vertical direction.

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Permalink Reply by j garrett on December 7, 2010 at 18:27

With all due respect Les, that's not the way the field rules read. Surface locations can be no more that 250 ft apart and the horizontal laterals can be no more than 300 ft apart, which means the fracs will overlap. This is stated in Rule4.1d . Rule 4.2 states "A Stacked Lateral Well, including all surface locations and horizontal drainholes comprising such Stacked Lateral Well, shall be considered as a single well for density and allowable purposes." Rule 4.6 states "...the operator will file a separate form G-1 or Form W-2 for record purposes only for the Commissions Proration Department to build a fictitious Record Well..." . Rule 4.7 : "...each surface location of a Stacked Lateral Well will be listed on the proration schedule, but no allowable shall be assigned for an individual surface location." "...and the sum of all drainhole test rates shall be reported as the test rate for the Record Well."

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Permalink Reply by j garrett on December 7, 2010 at 18:31

Here are the Texas field rules. Rule 4 is related to Stacked Laterals.

Attachments:

• Texas RRC Field Rules.pdf, 396 KB

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Permalink Reply by Les Bamburg on December 7, 2010 at 19:09

JG, I am familiar with stacked lateral field rules having read various field orders. If two "stacked laterals" are drilled into the Mid-Bossier Shale and Haynesville Shale the fractures may overlap horizontally but will not be in communication due to the vertical separation between the two formations.

The intent of the stacked laterals provision seems to be to allow two horizontal wells to be drilled inside the minimum spacing. Otherwise one of the two formations could not be properly drained.

If fractures from adjacent wells were to be in communication with each other it would reduce the gas recovery from each well and negatively impact their economics.

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Permalink Reply by j garrett on December 7, 2010 at 19:25

I believe I understand the wording "...fractures may overlap horizontally..." , but please clarify ".. but they will not be in communication due to the vertical separation between the two formations."

I believe the SL field rules are simply to allow full production from both intervals, which I believe are closer together than stated above. They are giving the operators the opportunity to maximize production. The Operators have to figure out the economics, but, gas prices won't stay where they are forever. At higher prices both wells will be economical even if they are bleeding a bit from one another. Combined production may be 35-50 mmcf instead of 20-30 mmcf from one well, as an example.

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Permalink Reply by adubu on December 8, 2010 at 1:29

j garrett-- are you saying there is not 600-800 feet vertical depth separating the bossier/haynesville formation? Have you seen logs sheets on the shale that IDs both and should show vertical depth separation of two? I sure it is variable to the location drilled i.e. Nothern La. vs Shelby -nacgodoches county, etc. Basically TRRC field rules require 80 acre spacing per well, but in truth with SL you get 2 in 1 wells so 16 counted as 8 in 640 acre unit. Cost to drills also almost doubles, but some saving on pad, location, rig movement,etc cost when second of two SL drilled.

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