Winchester Energy (ASX: WEL) will begin work this week on what it has described as a potentially “transformational” test of the Bonus Sands unit within its White Hat 3801 oil well in Texas.
The program will test previously unmapped sands in the shallower formation than were the targets in the original drilling four years ago.
The Three Fingers shale at the White Hat 3801 well contains a series of thin sandstones and sand laminations (known as the Bonus Sands play) within a gross interval of 60 feet (18m).
These thin sands and sand laminations potentially extend over between 5,000 and 7,000 acres (20.2 to 28.3sq km).
The Bonus Sands interval has been drilled in several wells at the White Hat Ranch, and all of them have oil and gas shows and hydrocarbons in samples.
Winchester said if this re-completion is successful, it will offer “substantial” follow-up potential with a number of other wells available for re-entry.
The program, including fracture stimulation, will cost less than US$150,000 (A$212,300) due to greatly reduced service prices as a result of the COVID-19 downturn.
Previously obscured porous sands
The White Hat 3801 well, located in Nolan County, was originally drilled in 2016 by a previous explorer.
Winchester has a 100% interest in the well.
The porous sands in this well have previously been obscured by the “hot” shale and therefore not recognised by previous operators, the company said.
Winchester’s testing of the Bonus Sands will include a slick-water fracture stimulation using 4,000 barrels of water to place 100,000 pounds (45,360kg) of proppant — that is, sand in water to keep the fissures open — into the formation.
Winchester said it expects this Bonus Sands play may provide commercial production using vertical wells rather than the more expensive horizontal drilling technique.
Winchester Energy’s ground is located in the highly productive eastern shelf of the Permian Basin in Texas.
The area in which Winchester Energy is operating has numerous productive units with a long-established history of oil and gas production.
Other well tests show insufficient hydrocarbons
In just over a year, the production base has been extended with two new production locations, Fry Sand in the Mustang oilfield and Cisco Sands in the Lightning oil field.
Meanwhile, Winchester reports that at White Hat 2004, further testing of two units in the upper Cisco Sands has been completed.
This well was first drilled in late 2019.
However, based on the results of these tests at White Hat 2004, the company has decided there is insufficient hydrocarbon returns to warrant fracture stimulation or further testing.
The tests cost about US$35,000 (A$49,537).