The Blake Field
The Blake field (RockRose – 30.82%) lies some 12 km north east of the Ross field and has been on production since 2001. Repsol Sinopec is the operator of the field. Hydrocarbons are contained in Lower Cretaceous turbiditic sands. The main reservoir is a massive channel sand sequence known as the Blake Channel which has excellent quality reservoir properties. Blake Flank comprises lower quality, thinner sands located to the north east of Blake Channel.
The two areas of the field have been developed separately. A total of six production wells and two water injectors have been drilled in the Channel, of which four and two respectively were in use in 2017. In the Flank, two production wells and one injection well have been drilled, all of which remain in use in 2017. The oil production rate in the Channel peaked at around 68 Mstb/d in 2001 and in the Flank at around 13 Msbt/d in 2004. The field is now at a mature stage of production, producing some 9.5 Mstb/d oil and 25 Mstb/d water in the Channel, a water curt of some 73%, and producing around 3.5 Msbt/d oil and 0.02 Mstb/d in the Flank, a water cut of around 1%. The cumulative production from the whole field as at 20/09/2017 is 98 MMstb.
The Blake Channel is at a depth of ca 5,200 ft ss and contains a 97 ft thick oil rim overlain by a gas cap. Blake Channel has been developed by six horizontal producers and two deviated water injectors. Oil production from the field commenced in June 2001, and water injection commenced at the same time as production.
The oil from the Blake field is produced via a subsea manifold and dual flowlines to the Ross FPSO. Since 2015 Ross stopped participating in the cost share for the FPSO. Instead OPEX for Ross was limited to a tariff based on produced oil rate, plus field specific OPEX. The operator is in the process of executing a Field Life Extension (FLE) project, which will maintain FPSO operability until 2024. With respect to costs, the operator and Rockrose continue to execute the FLE work scope and refine costs. Rockrose provided ERC Equipoise with a revised forecast of cost from July 2017, which ERC Equipoise reviewed and have taken into account in their analysis.