ExxonMobil, Hess unveil Pinktail as 20th significant discovery in Guyana's Stabroek Block

ExxonMobil and Hess have made another offshore deepwater discovery in Guyana on the Stabroek block, Pinktail, which Hess said may form the basis for a future development by mid-decade, the pair said Sept. 9.

Drilled in 5,938 feet of water, Pinktail is located 22 miles southeast of the partners' Liza Phase 1 project which began production in December 2019.

ExxonMobil is the operator of the block, with a 45% stake, in partnership with Hess, with 30%, and China's CNOOC, with 25%.

Pinktail is a "high-quality oil-bearing sandstone reservoir," Hess CEO John Hess said in webcast remarks at the Barclays CEO Energy-Power Conference in New York. "We think it has the potential to be coupled with Whiptail, a discovery announced earlier this year ... to be the sixth development" on Stabroek.

"It will have good economics," John Hess said. "[This] news today is very, very important in terms of going up the value queue in terms of what our next set of developments are."

Pinktail, which encountered 220 feet of net pay, is nearly four miles southeast of the Yellowtail Field – an earlier discovery that is moving toward a final investment decision, ExxonMobil and Hess said in separate statements.

Whiptail is located roughly three miles west of Yellowtail and about four miles southeast of the partners' Uaru discovery, also on Stabroek and announced in January 2020.

Deeper zones, quality hydrocarbons

"Whiptail and Pinktail both had deeper zones with good quality hydrocarbons in those zones," Hess Chief Operating Officer Greg Hill said at the conference. As the partners move forward, particularly at the end of this year, they plan to drill a well called "Fangtooth" targeting only that deeper zone, he said.

"That will be a real key piece of data," Hill said. "Fangtooth, if it's big enough, could potentially be a stand-alone hub on its own."

So far, only one of the 20 Stabroek discoveries is producing – Liza Phase 1, which came online in December 2019 and is now producing about 120,000 b/d of oil, the maximum capacity of its floating production, storage and offloading vessel. But the Liza Phase 2 development is slated to start up in early 2022 and a third development, Payara, should follow in 2024.

The Stabroek partners expect approval by the Guyana government for Yellowtail, the fourth development, by year-end 2021. Yellowtail, whose startup is anticipated in 2025, will be larger than the other three developments and will likely be produced through an FPSO with 250,000 b/d capacity, John Hess said.

By contrast, Liza Phase 2 and Payara are each designed to produce into an FPSO of 220,000 b/d.

Yellowtail: 'much larger' resource

Yellowtail will develop "a much larger resource base than any of the previous developments," Hill said. "So we're pretty excited about the overall economics of Yellowtail and also the size of the reservoir that it's going to develop."

The potentially fifth Stabroek development is envisioned for the Uaru discovery, which may be coupled into a development with the Mako find made in December 2019.

In any case, the fifth development is targeted for 2026 startup, followed by the sixth development in 2027, said John Hess, although those projects are still on the drawing board.

"In total, we see the potential for up to 10 FPSOs ultimately to develop the discovered resource to date on the Stabroek Block," he said.

So far, the partners have estimated 9 billion boe of recoverable resource on Stabroek. Pinktail will add to that total, ExxonMobil and Hess said.

"These discoveries are part of an extensive well program in the Stabroek Block utilizing six drillships to test play extensions and new concepts, evaluate existing discoveries and complete development wells for the Liza Phase 2 and Payara projects," said Mike Cousins, senior vice president of exploration and new ventures at ExxonMobil, said in its statement.

In addition to Pinktail, the partners announced Sept. 8 the successful appraisal of their Turbot discovery, which was the fifth significant find on Stabroek in October 2017.

The Turbot-2 well encountered 43 feet of net pay in a newly identified, high-quality hydrocarbon bearing sandstone reservoir, ExxonMobil and Hess said. But they added the reservoir is separate from the 75 feet of high quality, oil-bearing sandstone reservoir pay encountered in the original Turbot-1 discovery well.