Oil Basins Ltd., Melbourne, said consulting engineers recommended a stand-alone extended well test as the best option for developing Cyrano heavy oil field in the Carnarvon basin off Western Australia.
Earlier attempts to commercialize Cyrano have not succeeded. The field, in 15 m of water on the R3/R1 retention lease, has an estimated 10.12 million bbl of challenging, biodegraded, 23° gravity oil with 3.95 cp viscosity in place under a small gas cap at 700 m in a low pressure, low permeability reservoir.
The consultant, DU-EL Drilling Services Pty. Ltd., Perth, concluded that the most cost-effective development would be using a jackup rig or barge with a modular rig to drill and production-test two required extended reach wells each with 1,000-m horizontal sections.
The first two wells would be in the Mardie greensand, which produces at higher rates than the Airlie sandstones. The wells would be completed with electric submersible progressive cavity pumps. Recovery factors are assumed at 20-40%, or 2-4 million bbl of proved and probable recoverable. Preliminary economics are encouraging.
OBL will now assess the extension of nearby Nasutus oil field from R5 into R3/R1 and will seek partners to accelerate the Cyrano EWT development studies.