Abstract
Embla Field is located within the Greater Ekofisk Area in the Norwegian sector of the southern North Sea, 5 km south of the Eldfisk Field. A well drilled in 1974 indicated the presence of hydrocarbons. The producibility of the reservoir was proved by a well drilled in 1988. An appraisal well drilled in 1989 confirmed the discovery. During tests, the field produced volatile oil from a thick, pre-Jurassic sandstone sequence at about 4200 m TVD. Reservoir pressure is 828 bar and reservoir temperature is 159°C. A three phase development plan for the field was proposed and approved in 1990.
Seismic definition of both the top of the reservoir and its internal geometry is poor. Log, core, and DST information indicate that the reservoir is geologically complex. In order to allow for geologic complexity, minimize economic risk and obtain the necessary information for optimum reservoir management, the first phase of the development will be a low cost wellhead platform which will take advantage of the existing infrastructure. Production from this phase will start in late 1992.
Phase I will consist of pre-drilling up to 6 wells in a step-out fashion, installation of a remotely monitored 18 slot platform and one year of special reservoir monitoring from the pre-drilled wells. The reservoir monitoring program is designed to establish reservoir continuity and production characteristics. The information obtained information obtained from the first phase will form the basis for the rest of the development.
Phase II will include infill drilling and development of the remainder of the field. Phase III will be a pressure maintenance/improved recovery program.
Several alternative development schemes, including conventional delineation of the reservoir or test production through a subsea completion, were considered. The selected alternative best addressed the uncertainties of Embla while taking advantage of the existing infrastructure.
