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Permalink Reply by ScottM on January 21, 2014 at 7:36am

Is the "Ohio" shale part of the overall Marcellus formation or does it lie outside of it? I believe this well was considered a test well in 2006.

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Permalink Reply by James Vanderink on January 21, 2014 at 10:27am

Its better than playing dominos all day. Heres some info from Oxfords recent wells into the Ohio Shale.

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Permalink Reply by ScottM on January 21, 2014 at 12:29pm

Thanks for the info. Good to know. Hopefully another productive layer! !

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Permalink Reply by Thomas Rockwell on January 21, 2014 at 7:30pm

We happen to have one of those Oxford horizontals in the Ohio Shale.  Permitted for 3900', it only made it to 2500' (just enough to HBP our property.)  It has not done well.  After two years we finally started getting royalties--about 5 cents/acre/month, and that is with a nodding jenny.  I believe they listed 11 fracs on the well card.  The engineer indicated that their first horizontal had done well, and the reports support his claim, but apparently the pressure is just a little too low in the Ohio, due to it shallowness (2,500 feet)

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Permalink Reply by James Vanderink on January 22, 2014 at 12:41am

That's stinks, but I bet better days are ahead for you. Many layers here in Ohio that have great potential. NGO/Anadarko are going to try the Clinton with a long bore in Coshocton county. I bet the results will be kept close to the heart on that one because that would be a game changer.

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Permalink Reply by 0i7okn54zwbdo on January 22, 2014 at 3:53am

Drilling a horizontal Clinton well seems inefficient to me.  Anyone have any data that explains why a conventional trap reservoir would be economical for a horizontal bore?

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Permalink Reply by Steven A Joliat on January 22, 2014 at 4:24am

Among the variables to consider is the total surface area of the wellbore that lies in the productive zone of the formation.  A horizontal wellbore can offer a much greater surface area to drain oil and gas than several vertical wellbores.  It is not quite that simple and depending on the horizontal drilling vs conventional drilling and completion costs, it may prove uneconomic at times.  However, searching in an older conventional reservoir for those untapped pockets using 3D seismic isn't cheap either.

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Permalink Reply by 0i7okn54zwbdo on January 22, 2014 at 7:14am

Horizontal works well in shale because the shale contains the hydrocarbons fairly evenly across an area.  With conventional traps you may have a strong well drilled vertically and an offset 40 acres away that's a total dud.  So drilling in between the traps--which is going to more often be the case--seems wildly inefficient because the well bore will pass over hundreds of feet of ground that contains nothing at all.  What am I missing?

Permalink Reply by 0i7okn54zwbdo on January 22, 2014 at 7:25am

Clinton drilling is not that easy.

Permalink Reply by 0i7okn54zwbdo on January 22, 2014 at 7:45am

They happen.  It's about an 87% success rate, but that makes it even harder to understand spending the money for a horizontal.

Permalink Reply by pg guy on January 22, 2014 at 9:05am

Because the Clinton has been drilled so prolifically in eastern OH, there is likely minimal risk in such a project.  An O&G operator would research to identify an area where existing wells have good rocks, and then drill the horizonal through such an area.  The HZ borehole would steer between the older wells to hopefully drain an area beyond the drainage pattern of the earlier vertical well fracs.

Of course, even successful well construction through good rocks does not guarantee results, and the HZ well would have to significantly out-perform a vertical well in order to be an economic success, as the costs would likely be several times the cost of a vertical well.

Permalink Reply by Steven A Joliat on January 22, 2014 at 9:15am

I don't think it is that you have missed anything here Marcus, the key to your question lies in the type of reservoir model you describe.  As you have described the Clinton, it appears to be a disconnected set of small reservoirs of oil which is supported by your observation of results from conventional drilling on 40 acre spacing.  Production seems to be governed to some extent by fractures controlled by geologic structures.  A big if, which I suggest and may possibly match Anadarko's geologic model, is what if in some areas there may be a strong linear continuity to the reservoir, say long channel like accumulations that have somewhat better porosity and permeability.  This would provide an attractive target for horizontal drilling if the wells are maintained in the channels or bars.  This scenario also can explain why vertical wells can be relatively close together and vary wildly in production.  If some wells lie outside the linear trend of the reservoir they will never produce significant oil or gas.  Wells completed in the channel or bar produce from the area the fracture treatment enhances, so perhaps not much of the channel is drained.  A carefully situated multistage lateral may then replace several vertical wells.  However, if the reservoir is shallow enough, you have a good degree of confidence in your well siting, and you are using slim hole completions I would bet vertical trumps horizontal.

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