Transocean rig in the clear for drilling ops offshore Norway

Norwegian state-owned energy giant Equinor has received the go-ahead from the country’s authorities to use one of Transocean’s semi-submersible rigs for drilling operations at a field off the coast of Norway.

The Norwegian Ocean Industry Authority (Havtil) has granted Equinor consent to use the Transocean Encourage rig for production drilling at the Alve field in the Norwegian Sea, 16 kilometers southwest of the Norne field. The rig was hired on a nine-well contract, which comes with six more optional wells, for work on the Norwegian Continental Shelf (NCS).

The 2016-built Transocean Encourage rig is of GVA 4000 NCS design and can accommodate up to 130 people. According to the Norwegian offshore safety watchdog, the consent includes drilling of a production well. The water depth at the site is 370 meters. Following its discovery in 1990, Alve’s plan for development and operation (PDO) was approved in 2007.

The development concept is a standard subsea template with four production wells tied to the Norne production, storage, and offloading vessel (FPSO) by a pipeline. The production started in 2009. Equinor is the operator of Alve with a 53% stake. Other partners are DNO Norge (32%) and Orlen Upstream Norway (15%).

The field produces oil and gas from sandstone of Early and Middle Jurassic age in the Tilje, Not, and Garn formations. The reservoir, which lies at a depth of 3,600 meters, has moderate to good quality. The oil is offloaded from the FPSO Norne, and the gas is transported via the Norne pipeline to the Åsgard Transport System (ÅTS) and further to the Kårstø terminal for export.

As the long-term activity related to the field is all about optimizing production, an exemption from the PDO was granted in 2023 for the development of the discovery 6507/3-8, which was set to be drilled and produced from a well slot available on Norne.

The production is expected to start in 2025. Equinor secured the all-clear signal for the Verdande subsea development at the end of 2022 to replenish oil for the FPSO Norne. Verdande comprises the Cape Vulture and Alve North-East discoveries, which were proven in 2017 and 2020, respectively. 

The field is scheduled to come on stream in the fourth quarter of 2025. The extended life at Norne has the potential to lead to increased recovery, corresponding to 11 million barrels of oil equivalent until 2035, if production from Verdande becomes possible.