Slanted verticals

The SONRIS data indicates a well surface location and a bottom hole coordinate. The interactive map shows a straight line between the two, sort of indicating that the well bore is vertical, then goes horizontal from there.

It's recently dawned on me that this isn't necessarily true. A number of the wells have a perforation point that's offset from the surface location. i.e. the line drawn on the SONRIS map is not necessarily the correct location and orientation of the lateral.

A lot of the bores on SONRIS have strange looking angles on the lines drawn on the map, but the actual lateral could still run directly N-S.

I did a little geometry thinking and realize that, since the vertical depth of these wells is 10,000 feet, you can do a considerable offset between the surface location and penetration point and not increase the length of the vertical bore that much.

For instance, on a 10,000' vertical, offsetting the surface location 5000' from the perforation point only adds 11% to the length of the vertical bore.

I know some wells around lakes have slanted verticals. Are they using slanted verticals for lesser obstructions? It would seem that you have considerable freedom in choosing the surface location even if you want a particular location for the perforation point.

How difficult is it to drill a slanted vertical? Is it difficult to increase the slant past a certain angle?

I've seen quite a few applications that have slightly slanted verticals. Have any of you seen many wells that have more significant slants?

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Permalink Reply by Mac Davis on October 4, 2009 at 0:46
I understand, thanks.

What I'm wondering is if they're doing much directional drilling around here for purposes of locating the surface well at a more convenient place than directly over the end of the lateral. Or to drill multiple wells from one well pad?

And, is it significantly more effort to do directional drilling vs. vertical?

Do you have to "steer" the bit even when you're doing a vertical bore? Given the length of the vertical bores and the flexibility of the pipe involved, it would seem that the bore would tend to wander a lot if you don't do something to steer it. It would be rather unfortunate to see your drill bit coming up out of the ground a few hundred feet away.
Permalink Reply by The_Baron on October 5, 2009 at 5:14
CHk has done this with many wells here in the HA.
Permalink Reply by waltcop on October 5, 2009 at 13:09
Directional drilling does have to be recorded and filed with the drilling permit, and not to be used outside of the unit to drain someone elses minerals......RIGHT?
Permalink Reply by Missy on October 7, 2009 at 15:02
Electro, when you say, "correct" to Waltcops question, then say that it can be done, it seems to contradict. I understand what you mean but I think the answer to waltcops question is ".WRONG." They can , as you said, extract from another section and the guy with the rig sitting there will get ZERO unless he has mineral interest in the section. It would be great if all parties were made aware , but I doubt if this happens, unless one has legal counsel.
Permalink Reply by Missy on October 7, 2009 at 16:13
Perfect sense, I understand. I was looking at it from the standpoint of the surface owner, and he may be the mineral owner in the neighboring section. I am sure they wouldn't attempt to steal minerals, but I am not sure that the O&G company would make their drilling plan available to all parties. I am curious if anyone knows what amount is usual for a well bore easement? Thanks Electro
Permalink Reply by waltcop on October 7, 2009 at 17:18
Missy and Electro,
Thank you for explaning in detail about the question I raised. I had recalled the situation many years ago about the illegal drilling that took place and was hoping it had been stopped. But it does seem unfair if a rig can be placed in one section and directional drill into another without all parties affected being in full agreement. For an example, I am not the surface owner of one of my tracts but have 50% interest in the minerals. If the surface owner makes an agreement with an O & G company to place their rig on his tract and allow them to directional drill into his neighbors property, in Louisiana would this break the 10 year servatude and/or would he be required to share 50% of all receipts with me?
Permalink Reply by Mac Davis on October 8, 2009 at 12:47
waltcop, I think you get nothing, unless you have a specific agreement to retain ownership of surface drilling rights and/or subsurface drilling rights. (If such a thing is allowed by law.)

You own partial rights to the minerals under "your" land. You don't get any part of any income earned by any other activities on the land as long as they don't drain your minerals.

If the surface owner built apartments, you wouldn't get a cut in the profits. If he sold timber, you wouldn't get a cut. If he sold pipeline right of way, you wouldn't get a cut. If he leased part of the land for a drilling company to store equipment, you wouldn't get a cut. It's only when someone takes your minerals under "your" land that you're due payment.
Permalink Reply by Mac Davis on October 5, 2009 at 12:33
Why is the combination of directional drilling followed by horizontal particularly bad?
Permalink Reply by king john on October 6, 2009 at 0:35
i'm curious if there is some technlcal advantage to kick out drilling. there is a rash of drilling in the beaumont texas area and all the wells are drilled using this method. some are multi-bore from the same pad while others are single bore. all are kick outs.
kj
Permalink Reply by king john on October 6, 2009 at 2:20
i could see where hitting the pay zone at an angle would give slightly more exposure, can anyone think of any other advantages for this method of drilling?
kj
Permalink Reply by Mac Davis on October 6, 2009 at 5:48
What do you mean by "kick out drilling?" There's some advantage to moving the surface well slightly outside the unit you're drilling so that you can reach the proper depth for the lateral closer to the edge of the unit. It would seem that you could use a larger radius for the turn as well. Presumably a larger radius turn would be easier.

If you're talking about drilling an non-vertical bore down to the point where you make a turn, it would seem that only makes sense if you end up with a better location for the well pad. Either obstructions, cheaper prices from landowners, cost of roads, etc. It would seem that drilling multiple wells from one pad would save on cost for land, pipelines, equipment, etc. It would also do less damage to the environment.
Permalink Reply by Grillin' - MmmMmm on October 6, 2009 at 6:11
There are savings from locating multiple wells from a drilling pad. Particularly when completing the wells and piping them into facilities. You can locate one set of frac pits, tanks etc. and complete multiple wells without relocating the equipment and digger new pits. There are also surface use issues as you point out, but they aren't huge drivers across the majority of the HA. In other areas (like environmentally restricted areas) its a must.

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