A long-overlooked shale play in South Texas might finally be showing signs of promise, thanks to a surprising result from Formentera Partners in Frio County. After more than a decade of dashed hopes and uneconomic wells, a new horizontal test in the Pearsall Shale has delivered what may be the most encouraging result in years—and it’s turning heads.
Austin-based Formentera Partners has filed initial production (IP) data with the Texas Railroad Commission for its Hurrikain Cat I-STX #S731H well, a horizontal test in the Pearsall’s Lower Bexar member. Drilled to roughly 10,000 feet with a 7,862-foot lateral, the well posted a 24-hour IP of 1,499 barrels of oil and 4 MMcf of associated gas. That’s 191 barrels of oil per 1,000 feet of lateral—an unusually strong result for the Pearsall, a formation once dubbed the “heartbreak shale” due to its poor economics in past efforts.
The data was submitted on April 14. According to the report, the well had already produced 15,130 barrels by February 3, the date of the official IP test. Oil gravity was measured at 44 degrees, and the test was conducted on a 36/64 choke—standard for South Texas oil wells.
Formentera declined to comment on the results, but managing partner Bryan Sheffield previously hinted that the company’s strategy involved using longer laterals and modern, high-intensity frac designs—an approach notably different from the early 2010s wildcats, which relied on shorter laterals and far less aggressive completions.
This time, it looks like that shift is paying off.
A Strategic Shift in the Pearsall
The Hurrikain is situated in the southeastern corner of Frio County, an area that has seen little modern horizontal drilling. Its lateral tracks along Highway 1582, near the intersection with Highway 85. It was drilled from the same pad as Formentera’s earlier test, the Darlene 1-STX #N731HP, a pilot drilled last summer and filed as a shut-in well. That well was plugged back into the Pearsall after being drilled down to the Sligo formation.
Interestingly, the Hurrikain’s IP was filed using Form W-2—the Texas RRC’s oil well classification—rather than the typical gas well designation (Form G-1) seen in the Pearsall. It’s a subtle but significant indicator that Formentera sees this as a true oil well, rather than another gassy disappointment.
EOG Resources is also taking another swing at the Pearsall. The company drilled its Burns Ranch #1H test about 15 miles southwest of the Hurrikain location. It, too, filed an incomplete IP report in March, describing the well as a shut-in producer targeting the Pearsall at around 11,000 feet. The renewed activity from EOG and Formentera—two operators with proven track records in unconventional plays—suggests the Pearsall may finally be coming into focus.
Frac Evolution and Lessons from the Past
The difference this time may come down to the recipe.
Early Pearsall tests in the 2010s did yield oil, but with EURs that couldn’t justify continued development. The formation was deeper, hotter, and more challenging than its better-known neighbor, the Eagle Ford, which lies about 3,000 feet shallower in the area.
A good example is the Marathon Oil-operated Whitley-Dubose #1H, now owned by Britanco, which produced about 100,000 barrels over 10 years. The well’s 5,736-foot lateral was completed using just 16 barrels of fluid and 475 pounds of proppant per foot—numbers that look antiquated today.
Formentera’s approach is far more aggressive. Sheffield said last year that the company’s new completions would likely use 2,000 to 3,000 pounds of proppant per foot—more in line with high-intensity frac designs that have proven effective in other shale plays.
“If we go to 2,000 and 3,000 pounds per foot, you know that well is going to IP north of 400 bbl/d,” Sheffield told Hart Energy last fall.
Veteran South Texas wildcatter Rob Turnham agrees. After reviewing the well file, he described the result as “a very good well,” pointing to the 36/64 choke size as another encouraging sign. “It’s a good look at what the rock will do,” he said, emphasizing that the wide-open choke provides a more accurate snapshot than a constrained IP test would.
And the fact that the well had already been flowing for two weeks prior to the test gives more credibility to the result. “It’s not just one day at peak rate,” Turnham added.
The evolution of frac technology was always going to circle back to the Pearsall, he said. “With so many layers of pay in South Texas, it was only a matter of time before someone put a modern frac on it and made it work.”
Hope in the Heartbreak Shale?
Formentera’s early success doesn’t yet mean a full-blown Pearsall renaissance, but it’s clearly a signal worth watching. Between their modern approach to completions and their strategic positioning updip from earlier gas-prone Pearsall wells, the company appears to be methodically testing a long-dismissed play with fresh eyes—and a deeper toolbox.
That EOG is quietly pursuing its own Pearsall efforts nearby only adds to the intrigue.
For now, it remains to be seen whether the Hurrikain is a one-off win or the opening shot in a broader revival of the Pearsall Shale. But for the first time in over a decade, there’s a bit of excitement swirling around a formation that had been mostly written off.
And that alone is worth paying attention to.
