History Matching 20 years Production of a Complex Brent System

In recent times, there have been markedly less significant new discoveries in the UK sector of the North Sea. The focus has therefore shifted to optimizing recovery from marginal fields, and redevelopment of existing fields.

The Galapagos field (formerly North West Hutton) is located 130km north-east of the Shetland Islands in UK Block 211/27a, discovered in 1975 by the Amoco Group.

The Galapagos oil field had an in-place volume of more than 883 MMSTB (P50 estimate). The field was shut-in in 2003. The total oil production was about 124MMSTB from 52 wells, which represents 14% recovery, far below the average recovery of BRENT systems in the UK North Sea, even accounting for the known depth rock quality relationship. The field is highly compartmentalized by faults while shale barriers act as vertical baffles between producing zones.

As there is significant remaining oil in place, an in-depth evaluation of the field was undertaken to find a viable development plan for the field. The geological model and reservoir model were rebuilt, and a history match carried out. Approximately 20 years history data in 52 wells spread across several fault blocks (Water cut, BHP, GOR, PLT and RFT data) had to be matched.