See attached jpg of Rex Harvey 3H. This well is in Penn Township Butler County, Pa. The well pad location is behind the Gumto Greenhouse on Meridian Road. This well is producing at somewhat less than double the output of nearby Marcellus only wells.
impossible to drill and produce 2 formations from one lateral or all the companies would be doing it.......how would you drill two formations thru one pipe??????? have researched and can find no info on drilling two or more formations from one horizontal well
There is one vertical and two horizontals - look again. It is for real, I'm in that unit. Penn Energy Resources has done this same thing. Go to marcellusgas.org . Producing formations listed as Burket and Marcellus. Just from the gas output you would know something was different. I'm in another unit nearby this one with Marcellus only wells. They put out about half the production.
I worked an onshore project in the Arab Emirates where we accessed two zones horizontally from a vertical "mother bore". The casing was set just above the lower interval, which was drilled as usual. For the upper interval, we employed a Baker Hughes product called a "Lateral Entry Nipple" or (LEN). It was a whip stock and window mill combination. After orienting for depth and azimuth, the whip stock was set via drill pipe and weight slacked off on the drill pipe to shear a brass bolt to release the window mill, After milling the casing window, cement and a few tens of feet of upper zone formation, the pipe was tripped and a drilling assembly was attached to drill the upper layer.
As I recall, there was 80 to 100 feet of vertical distance between the two layers; design of the drilling assembly was critical to ensure that a turn from near vertical to horizontal could be made quickly without entering the lateral below or punching through the shale cap rock above the upper layer, which invariably ended in a stuck pipe situation.
The LEN had a machined profile that allowed wireline tools to be set to isolate either zone or to re-enter the upper zone with tools such as coiled tubing.
Accurately determining the production split between lower and upper zones was a huge problem, as was successfully getting coiled tubing tools over the lip of the upper whipstock re-entry device.
So far as I can recall, this project was the only use of the LEN anywhere the world, the product was not a huge success, but was fairly profitable for Baker Hughes.
The rock type that we were accessing in this example was tight, naturally fractured carbonate that we did not perform propped fracturing treatments in.
From my memory bank...
Thankfully also, drilling too technology for horizontal well drilling has progressed in leaps and bounds compared to the primitive methods that we used then
Thanks for the read Brian.
Talking over MY Head in many areas of the Drilling Technique you described using back then; and that's for sure (considering there's alot of unfamiliar (to me) natural gas & oil E & P jargon).
BUT, I'm still able to take away what I think is some very important / usefull stuff.
The important / useful stuff (to me) primarily being that stacked laterals have been done before (awhile back) in a marine application that you were personally involved in (albeit with some difficulty executing).
Also from this OP we're all informed that someone has successfully done it again - and recently - landside.
Also think it safe to say (agreeing with you) that it's probably easier to do now.
Oops - my bad.
I guess you were onshore developing two (2) laterals from one vertical when you were working the Arab Emirates well you wrote about above.
I must've skim read that portion and took your word onshore for offshore by error as I hurriedly tried to get to the details of how successful it all panned out.
So the double lateral well was onshore / landside then - better matching prospects for the technique to be applied in our geography !
Great then !
Coffeeguyzz & Brian,
Had to look up the term 'whipstock' and learned it is a tool that cuts a window / hole in the side of the vertical casing.
Wonder what the origin of that term is / was ? ?
The whipstock itself does no cutting, think of it as a casing anchor with a metallic slide that guides a mill or subsequent bottom hole assembly laterally into the casing below the anchor depth. I could draw one on a bar napkin, but we're trading thoughts/notes from our computers, not face to face over a beer or two (many).
The long ago story from my past was indeed onshore; but the concept could have been applied in an offshore environment; but getting good cement isolation at the window junction(s) was always a tough challenge.
Depending upon the rock mechanics and fracture treatment design, the frac of the lower zone may grow vertically into the upper zone.
Rex Energy responded to my inquiry about this unusual well construction and I was told (as others here suggested) that it was just a simple way to give Rex an option at the time of drilling. There was never any intent to drill a dual lateral well. In the end, they drilled the Marcellus on both the Harvey 3H and 5H.
Thanks for your technical input.
Now there's a twist that didn't occur to me until your latest reply.
Multiple laterals in a single strata.
Would it be appropriate / fair to be paid a sign on bonus / up front delay rental payment per each and every lateral developed regardless of which strata is developed ( covering the eventuality of multiple laterals in a single strata) ? ?
Something to at least try and float during a leasehold negotiation seems to me.
Has anyone had any success getting that Incorporated into a lease as yet ?
In my mind considering the agreed to royalty (say 15% of the production value) would be the same for the entire acreage pool (say 640 acres) it would not matter (to the land / mineral owner / Lessor) if the fractures of the long horizontals (laterals) merged vertically / horizontally / on the bias.
The only difference / money item for the land / mineral owner / Lessor would be the sign-on bonus / up front delay rental payment for each lateral.
How thick of a strata depth would be required to make multiple stacked laterals in the strata feasible and economically viable? Your best guess is acceptable, and I realize there are multiple variables in play here.