ExxonMobil and its partners have found more oil reserves in the Stabroek Block following the drilling of the Yellowtail-1 well, marking their 13th oil discovery in the offshore Guyanese concession.

Stena Carron - Daytime

Image: The Stena Carron drillship. Photo: courtesy of Hess Corporation.

Drilled to a depth of 18,445ft in 6,046ft of water, the Yellowtail-1 well intersected approximately 292ft of high-quality oil-bearing sandstone reservoir.

The well, located approximately 10km northwest of the Tilapia discovery, has been drilled using the Noble Tom Madden drill ship. The vessel is now scheduled to drill the Hammerhead-2 well.

In recent months, the firms have increased the recoverable resource estimates on the Stabroek Block to about 5.5 billion barrels, and the latest discovery adds to this total.

The Yellowtail-1 well is said to be the fifth discovery in the Turbot area, which is expected to become a major development hub, ExxonMobil said.

ExxonMobil Exploration and New Ventures senior vice-president Mike Cousins said: “Similar to the Liza area, successive discoveries in the Turbot area have continuously grown its shared value.

“Our success here can be attributed to our industry-leading upstream capabilities, the strength of our partnerships and our ongoing commitment to growing Guyana’s offshore potential.”

ExxonMobil affiliate Esso Exploration and Production Guyana operates the Stabroek Block with 45% stake, while Hess Guyana Exploration owns 30% interest.

The other partner in the block is CNOOC Petroleum Guyana, a wholly-owned subsidiary of CNOOC, with 25% stake.

Hess CEO John Hess said: “Yellowtail marks the 13th significant discovery on the Stabroek Block.

“As the fifth discovery in the greater Turbot area, it underpins another major development hub.”

The Noble Bob Douglas drillship is completing initial stages of development drilling for Liza Phase 1 project, while the Stena Carron vessel, following the completion of well test at Longtail-1 well, will move to drill the Hammerhead-3.

The Stena Carron vessel is scheduled to drill a second well at the Ranger discovery later in 2019.

ExxonMobil said that it plans to deploy another exploration vessel offshore Guyana to increase the total number of drillships on the Stabroek Block to four.