ExxonMobil’s projects in Guyana’s Stabroek Block carry hefty prices.
Its fifth – Uaru – carries the highest thus far: US$12.683 billion, since it will be the biggest offshore development, rivalling neighbouring Brazil.
These projects require massive floating, production, storage and offloading (FPSO) vessels but this is not what takes up the largest share of the development costs.
According to ExxonMobil Guyana’s President, Alistair Routledge, the lion’s share goes towards infrastructure underwater.
“We all look at the FPSO…[and] that is the obvious piece, but there is a lot that goes on, laid down on the seabed, the wells that are drilled – actually, something like two-thirds of the costs are in the wells and the subsea infrastructure,” he explained.
All of Exxon’s Guyana offshore developments requires Subsurface Umblicals, Risers and Flowlines (SURF) infrastructure that increases in size depending on the reservoirs being targeted.
Exxon’s first development – Liza Phase 1 – targeted 17 wells, with the Liza Destiny production vessel. Exxon and its co-venturers pumped US$4 million into this project. Those costs have already been recovered.
With Liza Phase Two, the price increased to US$6 billion.
It targeted a total of six drill centers as well as approximately 30 wells, including 15 for production, nine water injection and six gas injection wells. The Liza Unity vessel is being utilised for this.
And as projects got bigger, so did the development costs and well targets.
The Payara development with the Prosperity FPSO has a price tag of US$9 billion, with approximately 35-45 wells being drilled from 10 subsea drill centres.
Then there is Yellowtail, the fourth project, targeting the development of the Yellowtail and Redtail fields with approximately 41 to 67 development wells drilled from six drill centers, each with separate production, gas re-injection, and water injection manifolds.
And Exxon’s fifth project – Uaru – tapping into the Uaru, Mako and Snoek reservoirs. According to the project documents, approximately 38 to 63 development wells will be drilled. The combined recoverable reserve therein is 1.319 billion barrels of oil-equivalent,
According to Greg Hill, Hess Corp. Chief Operations Officer (COO), the SURF for Uaru will be twice as big as Yellowtail’s.