"The skunk at the picnic"......Marcellus Shale "Fault Lines"

 

What`s the story about faults found in the Marcellus Shale layer?  Are they always bad or sometimes good?  Do they make an area unsuitable for drilling & development now and forever, or are there strategies to overcome them?  Are faults common or found only in certain areas and why?   Is there a Pennsylvania map showing where these faults are located?   How do gas companies overcome the presence of faults?   Can they simply drill from another direction?  Has anyone had a unit or well plan cancelled because of the discovery of faults?   Wouldn`t a gas company investigate an interested area for faults before signing new leases or plan for a unit?  Does finding a fault mean that an specific area can not be developed?                               Is a fault the "skunk at the picnic" for landowners and lease owners ?

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Permalink Reply by farmgas on August 31, 2011 at 12:12am
Patrick & Area Man...please reply to my last posting.    As a landowner or lessor, what could one anticipate a gas company doing if faults are discovered?   Thanks....
Permalink Reply by Patrick DeBerry on August 31, 2011 at 2:56am

As I stated earlier, it is my understanding that the driller will select those locations where they have the best chance of hitting paydirt. The geology isn't the same across this play. You can't just lay out nice neat 640 acre units and drill in the middle of each one.  Anticipating what one of these gas companies will do is tricky business. I can tell you that they will do whatever is in their best interest which is maximizing the return on their investment to drill the well in the first place. That said, it is possible that some properties may never get included in a producing well. I would imagine that the smaller ones parcel is, the greater the chances of that happening. I detect a certain sense of urgency in your last post. If I could give you one piece of advice it would be to practice patience. You will sleep better at night!

 

0jw0dsu4txfuvPermalink Reply by 0jw0dsu4txfuv on August 31, 2011 at 9:30am

Proud someone else is attempting to answer these democrats questions,

Permalink Reply by farmgas on August 31, 2011 at 9:52am
Homer...what are you talking about?  This question is not related to politics...
Permalink Reply by Patrick DeBerry on August 31, 2011 at 11:53am

I'll be interested to see where this one goes now. I have an idea there will be a new "skunk at the picnic" very soon.

Permalink Reply by Hunter on September 8, 2011 at 3:06am
I'm a landowner, approached by a gas company (over a year ago) who is planning on 6 MS horizontal wells sometime in 2012.  Well site is on my property.  I have signed agreement papers, as have all property owners in the unit.  A road right of way agreement onto my property is done, and pipeline agreements to the closest compression station are just about completed, only to be told by my land man that a fault is now suspected.  Seismic testing was done several months ago along a road about 1-2 miles from my property.  I've been told the drilling on my land is now "on hold but not canceled".  Another nearby proposed MS well site (1-2 miles away, adjacent to the siesmic tested road) has been canceled due to the fault.  My land man wants to meet with me about this.  What questions should I be asking my land man?  Any advice?  Thanks.   
Permalink Reply by Area Man on September 8, 2011 at 3:27am

Hmm... not too much you can do - it's the will of the company drilling, how much risk they are willing to take and how they can mitigate.

For you to stay informed though, I would suggest asking how big the fault is (how much offset) and in what layers.

If it's shallow, it may be a gas migration issue.  If it's lower, closer to the Marcellus, then they may have to redesign the pad/drilling program... which may mean repermitting, pushing back the schedule.

 

Hope that helps some.

Permalink Reply by Ann Ticopa on September 8, 2011 at 5:56am

Several questions.  Can 2D vibrosis truck seismic detect faults?  Are faults more common in steep terrain with lots of rock outcrops?  Do salt layers interfere with seismic testing?  (I recently read that can be the case with oil well seismic.)

The last time browsed the new permits for my Northern PA county, about 12% of the permits were for reworks, mostly drilling deeper.  (Modestly deeper, not Utica Shale deep.)  Likely reason they didn't get it right the first time?

And, finally, how do they determine the depth to drill the vertical portion?   Is it "by the numbers", examining the cuttings, or something else?

 

 

 

 

Permalink Reply by Area Man on September 8, 2011 at 6:33am

Whoo, boy! Lot going on here. Ok, lemme see if I can hit all the questions here.
Can 2D detect faults? Of course! And that is likely what is being asked about here in general, something on that scale… because seismic has a finite resolution, that is, the offset on the fault must be >30’ or so or you won’t see it. SO, seismic (2D or 3D really) can detect plenty of faults, but there are always smaller faults (called subseismic) that WON’T show up and they can still ruin your day drilling.
Are faults more common in more mountainous regions? Not necessarily… but likely. The surface is going to be a product of tectonic forces – so stress the crust, create faults, movement along those faults creates surface topography. BUT, do these faults interact with the drilling target? Maybe the surface features are very young in comparison, so you have to drill through some faulted rocks to get to your target below, which is relatively stable. Or just the opposite. And anything in-between obviously.
Salt – well, salt screws everything up really. It doesn’t transmit seismic energy very well, so yes it does interfere with seismic imaging. As well, it is more mobile than most other surrounding rocks and will move, creating chaotic faulting and making things difficult to interpret.
Re-entering/deepening a well bore. Well, sure, maybe the operator missed on the first go. But usually, especially in this area, smaller, shallower targets were drilled. Then, fortuitously, a MUCH large field was discovered deeper down so it can be more profitable to re-enter, or even just use existing well pads or infrastructure to access these deeper horizons.
And finally, depth. This depends – if you say vertical “portion” I assume you mean on a horizontal well. The vertical will either be (1) until you reach your target (also called a pilot since you ‘tag’ your target so you KNOW where it is) where you plug back, go back uphole and build your curve, or (2) if you have data nearby where you are fairly sure you know the depth of the target then the drillers calculate at what rate they want to build to the 90 degree (or whatever) landing angle… so, say you want to be at 90 degrees at 10,000’ depth – if you need to build 90 degrees and the drillers are comfortable with 5 degrees per 100’, you can back out where you need to “kick-off” your horizontal portion.
Whew! Hope that helps. Cheers!

Permalink Reply by Ann Ticopa on September 8, 2011 at 9:28am
Thank you!
Permalink Reply by Don on September 8, 2011 at 4:20am
Would you mind giving the location of the proposed site? Thx
Permalink Reply by Hunter on September 8, 2011 at 8:47am

Don - Armstrong County, PA.  About 50 miles northeast of Pittsburgh.  Are you familiar with the area?

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