Summary
All deep water offshore projects are challenging. They are large
developments, difficult to implement and often beyond the limits of proven
technologies at their inception.
AKPO field is located in block Offshore Mining License (OML) 130, 200 km
offshore Nigeria in 1400 m of water. At plateau production, AKPO will produce
and export 175,000 B/D of condensate and will export, at startup, 320 MMscf/D
of gas to Bonny NLNG plant, onshore Nigeria.
AKPO reservoirs characteristics have greatly influenced the development
scheme while still making it technically and economically viable. AKPO
reservoirs consist in a 620-million-recoverable-barrels accumulation of a
critical fluid made of very light oils up to 53°API and classified as
condensate, with well head shut-in pressures up to 400 bars, fluid temperature
up to 116°C at wellhead, and very high gas liquid ratio (GLR). AKPO is not only
a giant condensate field, but also a gas field with 1 Tcf planned gas
export.
With such particular reservoir conditions, the AKPO development scheme is
very challenging and maximizes the use of proven and generic technologies
whenever possible.
The development is taking place at a time when the supplier market is very
buoyant. This, in turn, has created additional challenges with respect to the
availability of skilled resources and obtaining quality products on time.
The paper addresses the challenges of AKPO development and in particular
some of the key technical issues.
- A unique hybrid condensate production/gas export development scheme which
maximizes hydrocarbon recovery
- Reservoir management requiring massive pressure maintenance facilities,
extensive use of intelligent and selective completions, and subsea multiphase
flow measurements
- A development drilling strategy and well architecture.
- A subsea layout compromise, aiming at maximum reliability and
availability.
- Extensive qualification and testing program of equipment to meet with the
reservoir conditions.
- An FPSO concept pushed to the limit to handle high volume of high-pressure
(HP) fluids together with a very large gas inventory.
- The securing of resources in terms of dry dock slot, marine spread and deep
offshore drilling units in a buoyant market.
TOTAL, with 24% interest, is the operator on OML 130 on behalf of Petrobras
of Brazil, Sapetro of Nigeria, China National Offshore Oil Corporation of China
(CNOOC), and Nigerian National Petroleum Corporation (NNPC) of Nigeria.
AKPO achieved Project sanction on 25 April 2005, when OML 130 was awarded by
the Nigerian authorities. AKPO is currently under development with drilling and
construction underway, with first production planned before the end of
2008.
© 2008. Society of Petroleum Engineers
View full textPDF
(
709 KB
)
History
- Original manuscript received:
12 February 2007
- Meeting paper published:
30 April 2007
- Revised manuscript received:
18 February 2008
- Manuscript approved:
4 March 2008
- Version of record:
15 June 2008
View Cart
