Gryphon Field Development—Past, Present and Future

Abstract

Gryphon is an early Eocene age field located in block 9/18b and 9/18a-R of the UKCS North Sea. The field has been on production since October 1993 and comprises basin floor high-density turbidite sandstones within the Balder Formation. The thickly bedded Balder turbidite lobes of the Gryphon Field were remobilized during the early Eocene, probably by a catastrophic event such as an earthquake. This resulted in large-scale modification of the original depositional geometries of the sand lobes and the development of seismic scale sand injection wings. Initial field development was focused on the in-situ massive turbidite lobes. Since August 2004, production started from wells drilled into the injection wings. Going forward, oil reserves in the Gryphon area will be developed by active oil rim management and drilling of additional development wells. New development wells can be divided into two distinctive types: massive turbidite lobe targets and progressively more complex injection wing targets. Massive turbidite lobe targets are dynamic targets, generated through reservoir simulation. For this purpose, a completely new dynamic model has been built. Injection wing targets are less affected by existing production and are mainly driven by seismic observations. Given the complex nature of the remaining injection wing targets, technological developments are aimed at improving the seismic data quality. The new dynamic model also provides a tool to evaluate the resources and the development strategy for the last phase of the Gryphon Field, gas blowdown. Recent development drilling on the field and recognition of future potential, has allowed further facilities and topsides work to be carried out. This will allow the Gryphon Alpha FPSO to remain on station longer. It is the longest serving permanently moored FPSO in Europe and following the topsides work, the Vessel Class has been extended to early 2013. Introduction The Gryphon Field is located in UKCS Block 9/18b and 9/18a-R, 320 km northeast of Aberdeen, in the Beryl Embayment area of the south Viking Graben, adjacent to the Crawford Ridge. It was discovered in 1987 and has been on production since 1993. Geologically, it is a complex field and throughout its history, innovative solutions have been required to get the field into production and then maintain production. The application of new technologies has been key to the success of the field but the contribution of the teams who have worked on the field through its various phases of development has meant that the Gryphon Field and its satellites continue to produce. This paper documents some of the past and present challenges which have been overcome and discusses some of the future challenges.

Guidelines on Asset Management of Offshore Facilities for Monitoring, Sustainable Maintenance, and Safety Practices

“…This would help to prevent offshore accidents like Ranger I Mobile Offshore Drilling Unit (MODU), Petrobras-36, Macondo Well’s Deepwater Horizon Blowout and Piper Alpha offshore accidents [ 18 , 19 , 20 , 21 , 22 , 23 ]. In general, the offshore sector includes various activities, including shipping, logistics, wind farm scheduling, facilities maintenance, exploration, drilling, and production [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Asset management has also evolved into different management systems.…”