ExxonMobil expects the floating production, storage and offloading vessel planned for its Liza phase two development off Guyana to be installed on the giant oilfield in early 2022, with Dutch contractor SBM Offshore already understood to be carrying out front-end engineering and design work.
Construction of the spread-moored facility, which will have a design capacity rate of 220,000 barrels per day of oil, is likely to begin in the second quarter of 2019 and end in early in 2022, information in the US supermajor’s environmental impact assessment for the project shows.
The assessment, published by Guyana’s Environmental Protection Agency (EPA) this week in an EIA Final Terms of Reference document, outlines the entire scope for the second phase of development of the Liza field on the prolific Stabroek block, although details are based on conceptual work and are subject to change.
In all, the project involves engineering, development drilling, installation, hook-up of the FPSO, commissioning, start-up, operation and maintenance and, finally, decommissioning.
Engineering on the FPSO, wells plus umbilicals, risers and flowlines began in the second quarter, the lengthy documents shows, confirming information from a presentation by US independent project partner Hess last month that said that FEED work had started.
The planned development area is in the south-east portion of the block situated 183 kilometres north-east of the capital, Georgetown, and potentially extends over 76 square kilometres.
In total, ExxonMobil and its partners — China’s CNOOC Ltd, via Nexen, along with Hess — plan to drill up to 33 development wells, comprising producers, water injectors and gas re-injection wells. Wells will be drilled from two main drilling centres, with the operator considering using two drillships instead of just one unit.
Procurement of drilling assets is set to start early next year and run for two years, with drilling to begin in the first quarter of 2021.
“This schedule provides for simultaneous development drilling and FPSO/SURF production operations after start-up,” ExxonMobil wrote in the assessment.
Installation of the subsea equipment (set to comprise subsea production units, gas-reinjection and water injection wells as well as subsea manifolds) is anticipated to begin in 2020. Flowlines and umbilicals will measure between four and 13.5 kilometres, minus the risers, and will be installed in water depths of between 1600 and 1900 metres.
Associated gas not re-injected to the reservoir will be used, in part, to power the FPSO, which will be designed to handle up to 250,000 bpd of oil with a minimum storage capacity of 2 million barrels.
The vessel's produced water capacity will be 200,000 bpd, with a gas handling capacity of 400 million cubic feet per day, 30 MMcfd of which is seen being used as fuel gas for the FPSO.
SBM has already won the contract to supply ExxonMobil with the FPSO for Liza phase one and, although there has been no confirmation of an award, Upstream understands the Dutch company is currently carrying out engineering work on the second unit.
The FPSO will come equipped with an up to 20-point mooring line system and must remain moored in one location for at least 20 years, without requiring dry docking.
The floater must also be able to operate in extreme environmental conditions, ExxonMobil has stipulated.
ExxonMobil currently estimates the Stabroek block hosts 3.2 billion barrels of oil equivalent of recoverable resources, though its most recent exploration successes are not included in that total.
(This article has been amended from the original to correct the maximum length of flowlines and umbilicals for Liza 2 to 13.5 kilometres instead of 3.5 kilometres.)