| Popis: |
BP has been operating miscible gas injection projects in a variety of challenging environments throughout the world for over three decades. Numerous innovative techniques have been used to optimize oil recovery and the results have been reported in a series of publications.The focus of this paper is the North Sea, where BP operates offshore miscible gas floods in Magnus and Ula. Tertiary miscible WAG in Magnus began in 2002 and its impact on reservoir performance is significant and well understood. More than 175 Bscf of gas have been injected, yielding 18 mmstb of oil at a very high net efficiency of 3.5 mscf/stb. The contribution of EOR to total field production has increased to 40% by 2012. In Ula, tertiary miscible WAG started in 1998 and has played a key role in arresting production decline. More than 26 mmstb of oil has been recovered by gas injection by 2012. In 2013, close to 100% of the total field oil production is attributed to WAG. Key to the success of both projects has been securing a source of miscible gas and pursuing an active surveillance and reservoir management programme to monitor and optimize the flood.The success of the North Sea projects is partly based on the experience of operating the world’s largest miscible gas flood at Prudhoe Bay (Alaska), where conventional and unconventional techniques have been successfully applied in a variety of different settings. The knowledge acquired in Prudhoe Bay has been shared with other assets, including North Sea, through a series of managed moves and master classes.Miscible gas injection has generated considerable benefits for BP over the past three decades and will continue to do so in future. The potential availability of large sources of CO2 in the future, through carbon capture, could help maintain a leading role for miscible gas injection for years to come. |
