Application of Coupled Reservoir-Network Modeling for Early Field Production Optimization in Agbami Field, Deepwater Nigeria

Justin Mbala, Chris Aigbe, and Tony Oyewole
Agbami Deepwater Asset Development, Chevron International Exploration & Production (CIEP), Lagos, Nigeria

The Agbami field is located 70 miles offshore the Niger Delta in ~5000 feet of water. The field is composed of three major reservoirs subdivided by a thrust fault and a series of flank normal faults into seven producing areas. Agbami is planned as an all-subsea development with a total of 38 wells for miscible crestal-gas injection, down-dip peripheral water injection, and mid-flank oil production. Production is routed through six subsea manifolds into eight risers, then into two separation trains on the FPSO. Produced gas is compressed and routed to two subsea manifolds for re-injection. Water injection is fed into 4 subsea manifolds, with injection lines that run out to individual injection trees. Most first oil wells will have two interval control valves (ICVs) for both producers and injectors.

Because of the relative complexity of the field development, we implemented a full field coupled network model, which comprises of the full-field simulation model and subsea network up to the separator. The coupled model enables better understanding of the effects of downhole equipment (ICVs), wellbore interference, water and gas injection limitations, voidage balance on reservoir and field performance, during initial ramp-up and plateau maintenance.
This paper shows how we modeled the complex production and injection system, to capture relevant details and to optimize the operation of the system. Additionally, the paper will share challenges and best practices from Agbami coupled modeling efforts.

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