The Duyong field has undergone three major revisits since coming into production in 1984; drilling four new wells (1995), workover/evaluating the T reservoir (1999) and workover/testing the T reservoir (2001). In 2004 Nautec took part in Revisit IV campaign, looking at rejuvenating the Duyong field through maximisation of recoverable reserves, identifying infill and workover opportunities, and productivity enhancement opportunities.
The end client was Malaysian state oil company PETRONAS Carigali Sdn Bhd (PCSB).
A Full Field Review (FFR) was conducted to investigate the potential of infill and workover opportunities in order to develop the remaining reserves. The FFR scope of work included the following:
- Reservoir Characterisation (Geophysics, Petrophysics, Geology and Reservoir Engineering)
- Reservoir Modelling (both Static and Dynamic)
- Production Monitoring
Based upon these development opportunities generated during the FFR, the well engineering, drilling engineering, facilities engineering and the project economics aspects were evaluated for each development option during the Field Development Plan (FDP) phase.
The Value Added
The proposed Duyong Field Re-Development improved Duyong simulated fieldgas recovery factors by 47% to 60%, and an increase in recovery factor of up to 56% for condensate (from originally 42%). This was achieved through the optimum development scenario which consists of:
- Compression Restage
- 2 Workovers
- 2 Infill Wells
- Gas Jet Pump
A proposed Gas Jet Pump in-place of a new 8″ pipeline for gas evacuation from high pressure wells gave a cost saving of USD 20 million.