US oil major ExxonMobil has lifted its estimate for the Stabroek Block offshore Guyana to more than 4 billion barrels of oil equivalent (boe).
The previous recoverable resource estimate was 3.2bn boe.
The increase follows completion of testing at the Liza-5 appraisal well, a discovery at Ranger, incorporation of the eighth discovery, Longtail, into the Turbot area evaluation and completion of the Pacora discovery evaluation.
Neil Chapman, senior vice president, ExxonMobil, said: “Outstanding resource quality across these opportunities combined with industry-leading project execution capabilities will provide great value to resource owners, partners and our shareholders.
“Continued success in Guyana and progress in other upstream growth projects in the U.S. Permian Basin, Mozambique, Papua New Guinea and Brazil are giving us additional confidence in achieving our long-term earnings growth plans that we outlined in March.”
Guyana’s first development, Liza Phase 1, will use a floating production, storage and offloading (FPSO) vessel to produce 120,000 barrels of oil per day, starting by early 2020.
Liza Phase 2, which is targeted for sanctioning by the end of this year, will use an FPSO vessel designed to produce up to 220,000 barrels of oil per day and is expected to be producing by mid-2022.
The Liza-5 well successfully tested the northern portion of the Liza field and, along with the giant Payara field, will support a third phase of development in Guyana. The Payara development will target sanctioning in 2019 and will use an FPSO vessel designed to produce approximately 180,000 barrels of oil per day, as early as 2023.
The Longtail well established the Turbot-Longtail area as a potential development hub for recovery of more than 500 million oil-equivalent barrels. Additional prospects to be drilled in this area could increase this estimate.
The collective discoveries on the Stabroek Block to date have established the potential for up to five FPSOs producing over 750,000 barrels per day by 2025. There is potential for additional production from significant undrilled targets and plans for rapid exploration and appraisal drilling, including at the Ranger discovery.
The Stabroek Block is 6.6 million acres (26,800 square kilometers). ExxonMobil affiliate, Esso Exploration and Production Guyana Limited, is operator and holds 45 percent interest in the Stabroek Block. Hess Guyana Exploration Ltd. holds 30 percent interest and CNOOC Nexen Petroleum Guyana Limited holds 25 percent interest.