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Permalink Reply by Brian Powers on January 23, 2013 at 4:42am

Todd -

the assertion that the shale is 30 ft. thick and is organically rich suggests the potential for hydrocarbon potential, but a couple of things trouble me. First, the drillers who are landing the horizontal well have to geo-steer to keep the well within the 30 ft zone without entering the zones above or below the 30 ft organically rich window, which is not always an easy task. I worked on a conventional project in the Middle East where we used a mud logger studying the microscopic fossils in the drill cuttings to help steer the well. When we punched through to the shale above the top of this upper carbonate zone, we invariably got stuck and had difficulties getting the drill pipe free.

 

My second concern in a thin zone, no matter how organically promising, is in containing fracture growth in zone. Deeper hydraulic fractures tend to propogate vertically, and as any fracture grows, the fluid tends to find areas of higher permeabilty or natural fractures or fissues that allow the fluid to leak off and the frac proppant to bridge off, which terminates that stage of a multi-stage frac.

 

In my opinion, the developers will have probelems staying in zone and sucessfully fracing a 30 feet thin zone.

 

Brian

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Permalink Reply by David Perotto on January 23, 2013 at 6:01am

Brian,

I have read 50 ft is an approximate minimum. Does that sound accurate to you?

Dave

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Permalink Reply by Brian Powers on January 23, 2013 at 6:22am

David -

50 ft. sounds like a reasonable minimum thickness to me. If logging while drilling (LWD) tools are used, which measure the rock properties often used to confirm zone, such as gamma ray, resistivity and porosity, these tools are located 100-200 ft behind the bit. The meaurement while drilling (MWD) tools that measure depth, deviation and azimuth may be placedcloser to the bit in the drilling assembly. Depending upon how agreesively the hole angle needs to be changed to find the sweet spot of the zone, the bit could punch through below or above, and I reiterate my earlier concern.

 

A good directional driller with the correct tools and lots of experience could probably hit a 50 ft thick shale with minimal issues

 

Brian

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Permalink Reply by Billy Park Whyde on January 23, 2013 at 2:11pm

Interesting Brian. Working for a fracking company myself I find it all interesting. Was looking at some information that was 170 million years old  the other day in relation to the Rose Run. I guess it could be addictive.

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Permalink Reply by Todd on January 23, 2013 at 2:28pm

Thanks Brian.

The reason why I ask is that there seems to be alot of oil in the Marcellus in my area (northern WV panhandle) but the Marcellus Shale is only 30' thin at my location.  So far, the operator has drilled and completed an Upper Devonian well near my property with only minimal final open flow of calculated gas of 1166 Mcf/day and 5 bbl's of oil/day.  There is supposed to be alot of "super-rich" NGL's in this location though.

I appreciate your professional opinion on this!

Thanks again.

Todd

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Permalink Reply by Todd on January 23, 2013 at 3:57pm

Brian and David,

I just found that Range is drilling 7 wells from one pad to the 30' thick Marcellus Shale in my area.  So, perhaps, 30' is the new 50' threshold for fracing.

 

 

Attachments:

• Well Plat McMichael 007-20321 Marcellus 30ft Thick.pdf, 143 KB

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