Replies to This Discussion

Permalink Reply by Skip Peel - Mineral Consultant on Friday

Thanks, Ryan. It's hard to determine how a U-Turn well might stimulate the 330' set back without knowing stage lengths and perf cluster design and spacing.  Is it possible that the curve in such a well would produce from the set back zone.  Although the design may be more cost effective for an operator, does it still leave behind recoverable gas that is not produced in the unit?

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Permalink Reply by Ryan Howrish on Friday

This design does not change the first and last take points for gas. You drill ~1000ft or more of unproductive lateral,making the u-turn rather than drilling another ~10,000ft vertical section and well pad for a new well. The amount of unrecoverable gas is the same as drilling two separate wells with the same completed length.

You can see the unproductive zones on the plat of the GEP U-turn well.

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Permalink Reply by Skip Peel - Mineral Consultant on Friday

Thanks.  That's what I was concerned about.  The design simply creates additional stranded reserves in the no-perf zone.

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Permalink Reply by Ryan Howrish on Friday

It does not create additional stranded reserves, it just follows the existing 330ft setback rules.  If the rules change, a design like this could be used to cause less waste.

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Permalink Reply by Skip Peel - Mineral Consultant on Friday

If there is no opportunity to drill an HC well into the unit with the U-Turn well(s) how would the 330' no-perf zone be stimulated and produced?

Permalink Reply by Ryan Howrish on Friday

It is not without challenges, but you could perforate and stimulate around the U.  That would require changes to the directional plan, and it's not without risk.  Due to the off-azimuth direction of the U portion of the lateral, I would expect that section of the well to be less productive.  If the choice is never drain that area, or try something while you are already in the hole for minimal incremental capital, someone might try it. All a moot point while the 330ft offset rule exists.

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Permalink Reply by Skip Peel - Mineral Consultant on Friday

Thanks, Ryan.  You can tell that the no-perf zones are a concern of mine for how to produce them and not leave them stranded.  Would what you suggest for stimulating around the U portion be worth a re-frac?

Permalink Reply by M B Gilster on Monday

The U-Turn discussion is timely as I've been receiving notices concerning CHK's permit/application/drill etc. in Bethany Longstreet (Pankey) specifically HA RA SU75. utilizing the U-Turn method.

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Permalink Reply by Ryan Howrish on Friday

I agree the no-perf zone is a challenge but unfortunately there are several thousand wells and hundreds of units developed that are unlikely to ever produce from the 330ft offset in LA.

It may not be worth stimulating the U portion of the lateral. I don’t know that it has been tried anywhere onshore? If the commission allows for it, someone might try it.

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Permalink Reply by Rock Man on Friday

I am pretty sure that operators are perforating the "bottom of the U" curve in the Permian Basin.

Even with the 330' stand off line, perf'ing this zone accesses the
330' interval via the frac and growth of stimulated rock volume in that area

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Permalink Reply by Skip Peel - Mineral Consultant on Friday

Drainage outside of a unit boundary was always a big deal in the days of conventional reservoir development.  The distance that those wells could produce from could be quite large in formations with high porosity and permeability.  The old regulations die hard even though regulators now deal largely with unconventional production.  The possibility that a well may produce some molecules slightly outside of a unit boundary should not be a hindrance to maximizing production of recoverable reserves.  This has puzzled me for some time since state regulators tend to fall over themselves in the rush to approve changes to regulations requested by the industry.  The Haynesville Shale being a good example.

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Permalink Reply by Ryan Howrish on Monday

My thoughts are that if 330' stages efficiently drained that area with large fracs, stages would not be spaced 120-140ft apart.  One of the significant step changes in productivity from the first several years of development to today is the reduction in stage and cluster spacing. We spent a ton of money in the Marcellus, Eagle Ford, Austin Chalk, and Haynesville trying to understand the impact different completion designs had on productivity.  I think the reason lots of old wells with 300-400ft stage spacing are identified as re-frac candidates is because the fluid and proppant loading was too light and the stage and cluster spaicng was too wide.  I think very little gas is efficiently drained much beyond the last perf cluster at the hell and toe of wells.

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