ExxonMobil and its partners have made an oil discovery at the Longtail-3 well in the Stabroek Block offshore Guyana.

The well has been drilled to a total depth of more than 6,100ft using the Stena DrillMAX rig.

It is located approximately 3.5km south of the Longtail-1 well, where approximately 256ft of oil-bearing sandstone reservoir was identified in 2018.

Following the drilling, the Longtail-3 well encountered 230ft of net pay, including newly identified, high-quality hydrocarbon-bearing reservoirs below the original Longtail-1 discovery intervals.

ExxonMobil exploration and new ventures senior vice-president Mike Cousins said: “Longtail-3, combined with our recent discovery at Uaru-2, has the potential to increase our resource estimate within the Stabroek block, demonstrating further growth of this world-class resource and our high-potential development opportunities offshore Guyana.

“We will continue to leverage our core competitive advantages in our ongoing exploration campaign, delivering substantial value to the Guyanese people, our partners and shareholders.”

The Stena DrillMAX will now be moved to drill the Whiptail-1 exploratory well on the Stabroek block, as part of the planned 15-well campaign.

The partners plan to use the Noble Sam Croft rig to support development drilling work for Liza Phase 2 development offshore Guyana.

In other drilling activity at the Mako-2 appraisal well in the Stabroek block, ExxonMobil confirmed the quality, thickness, and areal extent of the reservoir.

Together with the previously announced Uaru-2 discovery, the latest results suggest potential deployment of a fifth floating production storage and offloading vessel (FPSO) in the east of the Liza complex.

ExxonMobil affiliate Esso Exploration and Production Guyana operators the Stabroek Block with 45% interest.

Other partners include Hess Guyana Exploration (30%) and CNOOC Petroleum Guyana (25%), a wholly owned subsidiary of CNOOC Limited.