Replies to This Discussion

Permalink Reply by Two Dogs, Pirate on December 17, 2008 at 16:43

It allows for re-fracking from now until the cows come home and any frack thereafter.

• ▶ Reply

Permalink Reply by Bruce on December 17, 2008 at 16:51

I realize every well has its own characteristics, but is there a "norm" on the number of times a well can be refraced and what kind of production rates do they have in comparison to ip rates? What can we look for in relation to the haynesville shale and its refracing production rates? Any ideas? Thanks

• ▶ Reply

Permalink Reply by Two Dogs, Pirate on December 17, 2008 at 16:57

I am not an expert in this but I would think they would start from the bottom of the formation and work up.

• ▶ Reply

Permalink Reply by The_Baron on December 17, 2008 at 17:23

?????

The bottom In a horizontal? The last few big wells are done with a multiple stage frac (at least six stages). The start at the end of the bore and work their way back. Each time the part of the well already fraced must be sealed off with a packer, and a new perferation is made, that zone is fraked and so on.

In a traditional vertical well, yes it is possible to come in and perferate into a higher formation and frak it, but I would be suprised if you could go into a latteral and frac it again.

• ▶ Reply

Permalink Reply by Bruce on December 18, 2008 at 14:36

Let me see if I am understanding you right Baron, you are saying a haynesville shale well could be fraced at 6 different depths, which would be done when the bottom most depth had depleted its production they would frac the next level and so on. Has there been any studies or estimates on how long a frac on a Haynesville well could possible last? If so then could we estimate that length of time by 6 to get a total lifespan of a haynesville shale well? I find all of this very interesting and apologize if my questions seem so elementary but I would really like to know and I bet I am not the only one. Thanks everyone for your help and have a nice day!

• ▶ Reply

Permalink Reply by Les Bamburg on December 18, 2008 at 15:18

Bruce, most O&G companies have indicated that refracing is not an economic option for many of the shale gas plays. It was utilized by Devon on some of their original vertical wells in the Barnett Shale in areas with ~ 500' of thickness. With the current 10-12 stage frac jobs on Haynesville Shale horizontals and 80-acre spacing most of the economic gas should be recovered.

• ▶ Reply

Permalink Reply by Bruce on December 18, 2008 at 15:44

Thanks Jim and Les I appreciate the input and the clarity that both of you have provided. I would like to ask one other thing. I have heard lifespan estimates from 10 to 50 years from a Haynesville well, has there been some kind of consensus on the true lifespan of a well or is it still just an educated guess? Jim for instance on a 16mmcf well, with the bulk of production being in 3 years, what kind of daily production could be expected after that? I guess what I'm trying to get a handle on is how the per acre royalty is affected over the lifetime of a well. Thanks for your input.

• ▶ Reply

Permalink Reply by Les Bamburg on December 18, 2008 at 16:08

Bruce, the general consensus is 30 years but this only based on estimates & projections. Attached is an example decline curve I created for a Haynesville Shale horizontal well with a 11.7 MMcfd initial rate and 30 year life. Projected production rates at different times is as follows:

5 years - 836 Mcfd
10 years - 542 Mcfd
20 years - 269 Mcfd
30 years - 134 Mcfd

Attachments:

• HS Well Decline 12-18-08.pdf, 103 KB

• ▶ Reply

Permalink Reply by Grillin' - MmmMmm on December 18, 2008 at 16:10

There are a couple of threads regarding decline curves. Bottom line, though, is that without a lot of production data its all extrapolation and estimation. Many are using the Barnett Shale decline curves as a model which is probably pretty good. This shows the well to decline rapidly during the first year (70% or so) and then that drops off hyperbolically. After 3-4 years, the well rate will start to level out and decline in the single digit range. But that rate is usually in the 100-300 mcf/day range. again, this is conjecture at this point but the science is pretty good.

So, take a 20 MMCF/day well on the initial test; by the end of year one expect it to be in the 6 MMCF/day range. But this will also depend on pipeline constraints and other things. If the wells are "choked back" since there is no pipeline capacity, the decline rate will be less until the pressure declines to a point where it hits the pipeline pressures. The other threads have much more detail and conjecture. This is the Readers Digest version.

• ▶ Reply

Permalink Reply by Bruce on December 18, 2008 at 16:23

Les thanks for the well lifespan curve and estimates, it is amazing how it drops off the first three years! I appreciate the work you did to explain this to me and everyone else and Mmmarkkk I never considered pipeline constraints and other extraneous things such as that but I see how that could affect rates as well. Once again the experts come through. Thanks guys!

• ▶ Reply

Permalink Reply by Bruce on December 18, 2008 at 17:55

Thanks Jim for your response. The variables are enormous for each well I am seeing and I appreciate every one for pointing this out. The enormity of it all boggles the mind but it truly is very interesting and I want to learn all I can. Thanks everybody for your help.

• ▶ Reply

Permalink Reply by Clay on December 19, 2008 at 10:24

Haynesville wells can be re-stimulated at a later date due to the fact that they are tight rock wells, but the decline of a Haynesville well is unknown thereafter and the increase of production from the 2nd, 3rd, 4th, etc... frac would be unknown as well. However, I can tell you that (according to reputable individuals in the Barnett) the second frac of a Barnett well would bring the production back to 65% of its original Mcf/day. Now keep in mind that the porosity of the Haynesville is more than that of a Barnett and the decline curve is more as well, so all of this will have some effect on the future fracs. There will come a time when it is not cost efficient to re-frac a well. Consider this – the Haynesville is like a thick piece of marble and each time you frac into it, it shatters that much more, when will it turn to rubble and not yield enough gas to maintain production and operation costs? That is the question that will be answered on a case - by – case basis WAY in the future.

Also, I have heard that an average Barnett well can be re-stimulated about 4 times throughout its life. Once again, this is all based off of estimates considering the Barnett has not reached that stage yet.

• ▶ Reply

• ‹ Previous
• 1
• 2
• 3
• 4
• Next ›
• Page