AKPO: -A GIANT DEEP OFFSHORE DEVELOPMENT.
Development of deep offshore fields such as the Akpo field which is located in water depth of up to 1800m have for long posed technological challenges in the industry especially due to conditions of very high pressures and low temperature with depth coupled with the challenge of unconsolidated and unstable Reservoirs. Today the story has changed with success stories such as Akpo?s. The Field Development architecture provides for a complex network of Umblicals, Flowlines and Risers connecting the Subsea Production Systems to the FPSO.
The Akpo Floating Production Storage and Offloading vessel (FPSO) is a purpose-built double-hulled vessel, 300m long, 61m wide and 31m high (keel to Hull deck) with a dry weight of 100,000 tons. The Hull has thirteen off-cargo tanks aligned in three rows along the Hull to store the stabilized AKPO condensate in addition to the usual storage for diesel, methanol, and ballasting requirements.
The hydrocarbon-production facilities and support systems are in fifteen Topsides modules. The Topsides processing facilities consists of single-train four-staged separation and an electrostatic dehydrator to meet the basic sediment and water specification. Akpo FPSO has oil storage and production capacities of 2 million barrels and 185,000 bopd, respectively.
Subsea Production System
The subsea production system links a complex arrangement of trees, wellheads, subsea manifold, and subsea controls with the FPSO and the intervention equipment in such a way that the retrieval of trees or manifolds is without having to lift the spools or jumpers.
There is a high level of redundancy in the control systems. The equipment is modular so that trees can be separated from the wellheads, leaving the down-hole completion intact, and all chokes, subsea control modules (SCMs), distribution units on the manifold, accumulator packages, flowline jumpers, and electrical and hydraulic flying leads are individually retrievable. Each SCM has two independent control paths- electrical and hydraulic. No two trees share the same two lines.
AKPO FPSO Milestones