Blog: Wells that go around the corner

For a few years now, unconventional oil and gas operators in the USA managed to squeeze 2 mile laterals in 1 mile acreages, by drilling lateral section of shale wells across lease areas, turning them and drilling a return section inside the same lease. Shell was the pioneer, with the first horseshoe well (NEELIE 1-85 LOV-4H) drilled in Loving County, Texas in 2019. It was followed by a few companies replicating the intriguing design over the next years.

Stacked paperclips drilled by Oxy in Eddy County, New Mexico

U-turn, U-Laterals, horseshoe wells or paperclip wells were drilled in Wolfcamp and Bone Springs targets in the Permian Basin (in both Delaware and Midland sub-basins), also in the Eagle Ford shale, Niobrara and Utica shale. About 50 paperclip wells were executed in the US between 2020 and 2024.

More details about US paperclips can be found here:

A paperclip well design consists of a vertical hole, followed by a curve (or build section) that lands the well in the desired reservoir, then an ongoing leg, a 180 degrees turn that points the well in the opposite azimuth direction, and a return leg that brings the well close to the original landing point, thus doubling up on lateral length, even when constricted by mineral lease area. Wells can be stacked in multiple benches, or crossing over between benches.

Niobrara crossing paperclips drilled by Bison in Weld County, Colorado

Many Bakken wells in North Dakota have high turns in the lateral section, bending around land parcel boundaries to maximize drainage. The design earned the nickname “boomerang well” for its curved shape.

North Dakota Bakken boomerang wells

Canadian bent wells

High turn wells, where azimuth changes more than 180 degrees in the horizontal part of the well, have been drilled in Canada as well.

Obsidian (still named Penn West at the time) drilled a string of multilateral collector wells, with legs reaching between other Bluesky multilateral wells. The complicated well designs contained between 25 and 47 legs.

Obsidian Bluesky multilaterals in Peace River oilsands

One of these wells, 100043008318W500, drilled in 2015, has legs on both sides of the build section that bend more than 180 degrees. Five of the 35 legs exhibit trajectories that start heading West and end up East bound.

Boomerang wells

Single leg boomerang wells, with horizontal sections turning up to 90 degrees in the middle of the lateral, were drilled by Kelt in Valhalla, targeting the Montney silt/shale. The first lateral of this kind dates back to 2015, when 102120807811W600 was drilled with a turn of 78 degrees midway through the lateral section.

Kelt Montney wells in Valhalla – plan view

Several other wells were drilled nearby, with turns of up to 90 degrees, , sometimes in stacked benches of the Montney Formation.

Kelt Montney wells in Valhalla – 3D view

Drill-bit multilateral exploration

Ghost River kicked off several legs in different directions in their 100140503503W400 well, drilled in 2021. The well ended up with leg 6 turning 155 degrees in the lateral. Flexible well designs, and the ability to change directional plans on the fly makes this approach feasible when chasing thin sand beds with variable thickness.

Variable turn Sparky multi-leg drilled by Ghost River in eastern Alberta

The high lateral turn was not executed to extend the well, but rather to search for better sand in the laterally variable reservoir.

Cenovus drilled a few multilateral well targeting the Cummings member of the Mannville Group in their Rivercourse property in Eastern Alberta.

One of these wells, 100130104701W400, drilled in 2024, has legs draining the Cummings sand, extending for as long as good quality sand was observed in the well. Leg 5 bends a full 174 degrees in the lateral.

More boomerang wells are planned in unconventional reservoirs in Canada, with operators maximizing access to their resource when land access is tight. Throughout 2025, we were anxiously awaiting the first full bend U-Turn to be drilled in Canada. It did not take long to see the first achievements in this direction.

Canadian Paperclip wells

The first unconventional well with a significant turn in the lateral is CNRL HZ KAYBOBS 7-26-61-20, with the horizontal section turning from 85 azimuth to 315, a turn of 130 degrees. Not quite 180 for a full U-Turn, the well is closer to a V-Turn, or a C-Turn.

Still, this trajectory resembles an unraveled paperclip, so it fits the category. The well is drilled in the Duvernay Formation, at a vertical depth of 3,200 meters, to a total depth of 6,611 meters. CNRL used rig Ensign 770, with SLB providing directional services and Chinook Consulting providing geosteering services.

CNRL fitted a 6,600 meter long well in a leftover triangular acreage crammed between legacy wells drilled North-South and newer wells drilled along strike.

In September 2025, Ovintiv and Phoenix Technology Services drilled well OVV HZ DAWSON CREEK J10-35-077-15 just south of Dawson Creek. Drilling concluded at the end of September. This is now the first full U-Turn well drilled in Canada.

Plan view of OVV HZ DAWSON CREEK J10-35-077-15W6 immediately South of the City of Dawson Creek

The Lower Montney well was drilled to a total depth of 5,570 meters, at a vertical depth of 2,460 meters, with a lateral section of about 3,000 meters. Almost two miles of production hole was fitted in a one square mile section of land, that already had a well drilled obliquely in the same bench. Close proximity of the City of Dawson Creek impedes drilling longer wells straight north from this location.

3D View of OVV HZ DAWSON CREEK J10-35-077-15W6 in a multi-well pad
Cross-section depicting wells drilled in two Montney benches

A month later, Yangarra Resources Ltd. drilled well YANGARRA HZ FERRIER 3-29-39-8W5. The Cardium well was drilled to a Total Depth of 4,078 meters.

Plan view of YANGARRA HZ FERRIER 3-29-39-8W5

The well, drilled with Altitude Energy Partners directional drilling, has a 1,325 meter long lateral section. Almost a mile of lateral length was drilled in a quarter section (a quarter square mile).

3D view of YANGARRA HZ FERRIER 3-29-39-8W5 drilled from a multi-well pad
Cross-section depicting YANGARRA HZ FERRIER 3-29-39-8W5, drilled immediately below the Cardium Sandstone

Turning from 170 to 355 degrees azimuth, this is the first full turn U-Turn well in Alberta, and the first Cardium well to bend more than 180 degrees in the lateral section.

Chinook Consulting Services provided reservoir navigation services for several U-Turn wells in Canada, the Permian Basin and Eagle Ford Shale in Texas.

(c) Chinook Consulting Services, August 2025, updated January 2026

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Author:
Calin Dragoie

Posted On:
August 11, 2025

Category:
Drilling, Geoscience, Posts, Technical Articles