The Gannet cluster (North Sea, U.K. sector) consists of four fields producing into shared surface facilities. To aid in the reservoir management for the total cluster, an integrated simulation model was constructed to represent the dynamic interaction between sub-surface and surface processes. This model comprises four reservoir simulation models representing the sub-surface for the Gannet fields dynamically linked to a model representing the shared surface facilities. This paper describes the functionality of the integrated model and its application to a number of integrated reservoir management issues.
The Gannet cluster is located in the U.K. sector of the North Sea some 180 km due east of Aberdeen. It comprises four fields, Gannet A, B, C and D; the platform is located over Gannet A; the other three fields are sub-sea tie-backs to the Gannet platform (see Figure 1). The four fields produce into shared surface facilities located at the Gannet platform. Three of the four fields are oil fields (A, C and D), which also produce significant amounts of associated gas whilst the fourth field (B) is a gas field. The Gannet gas is sold under a long term contract. The overall objective of Gannet development is to maximise hydrocarbon recovery whilst satisfying the gas sales requirements.
In this section, a summary of the main sub-surface characteristics of the individual Gannet fields and a description of the Gannet surface process is given.
The Gannet B field is a gas field which acts a swing producer. Rates from the Gannet B field fluctuate over the year due to the seasonal swing in the contractual nominations. The field is developed with two deviated (600) wells.
The Gannet A and C fields consist of oil rims (53 ft and 400 ft respectively) overlain by a large gascap. Both fields receive strong aquifer support.