ExxonMobil announced an oil discovery offshore Guyana at the Mako-1 well southeast of the Liza field, marking the 15^th discovery on the Stabroek Block.

Mako-1 encountered approximately 164 feet (50 meters) of a high-quality oil bearing sandstone reservoir. Mako-1, drilled in 5,315 feet (1,620 meters) of water, is located approximately six miles (10 kilometers) southeast of the Liza field, which began producing oil in December 2019. (Earlier post.)

The discovery adds to the previously announced estimated recoverable resource of more than 6 billion oil-equivalent barrels on the Stabroek Block.

New discoveries in this world-class basin have the potential to support additional developments. Our proprietary full-wave seismic inversion technology continues to help us better define our discovered resource and move rapidly to the development phase.

—Mike Cousins, senior vice president of exploration and new ventures at ExxonMobil

The full wavefield inversion (FWI) approach is a significant departure from the way seismic data are currently used to image the subsurface, ExxonMobil says Standard seismic analysis is time- and labor-intensive, consisting of a series of operations designed to remove noise and unwanted signals from the data prior to imaging. After imaging, subsurface properties are estimated, but there is no explicit feedback loop to compare these estimates with the original field data. In contrast, the FWI process is largely automated using computer simulation to bypass the time-consuming steps of the traditional approach.

ExxonMobil’s proprietary algorithms and investments in supercomputers allow it to increase the range of frequencies used by full wavefield inversion so it can create remarkably precise maps of subsurface structures.

In most published FWI studies, only the lowest frequency portion (less than 10 Hz) of data using simple simulation physics is inverted, resulting in low-resolution models. ExxonMobil has run FWI on 3-D seismic surveys using higher frequencies and more simulation physics, generating high-resolution and more accurate models of the subsurface.

The improved imaging and reservoir characterization provided by FWI has translated to improved results in the field. As one example, high-resolution seismic images and models derived from our FWI technology were used to target drilling optimally and form an integral part of the company’s ongoing activities in Guyana.

The Liza Phase 1 development achieved first oil on 20 December 2019 and will produce up to 120,000 barrels of oil per day utilizing the Liza Destiny floating production storage and offloading vessel (FPSO).

The Liza Unity FPSO, which will be employed for the second phase of Liza development and will have a production capacity of 220,000 barrels of oil per day, is under construction and expected to start production by mid-2022.

Pending government approvals and project sanctioning of a third development, production from the Payara field north of the Liza discoveries could start as early as 2023, reaching an estimated 220,000 barrels of oil per day.

Drilling activities in Guyana continue with four drillships to further explore and appraise new resources as well as develop the resources within approved projects.

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% interest in the Stabroek Block. Hess Guyana Exploration Ltd. holds 30% interest and CNOOC Petroleum Guyana Limited, a wholly-owned subsidiary of CNOOC Limited, holds 25% interest.

Resources

• Jerome R. Krebs, John E. Anderson, David Hinkley, Ramesh Neelamani, Sunwoong Lee, Anatoly Baumstein, and Martin-Daniel Lacasse (2009) “Fast full-wavefield seismic inversion using encoded sources” Geophysics 74:6, WCC177-WCC188 doi: 10.1190/1.3230502