Shell Nigeria Exploration and Production Co. (SNEPCo) finished a remotely controlled well completion operation in the Gulf of Guinea.

Optime Subsea, which supplied the operation’s remotely operated controls system (ROCS), announced the operation at the Bonga Field in 1,060 m water depth offshore Nigeria on Feb. 27. Optime Subsea has performed multiple ROCS operations in the North Sea and Gulf of Mexico and said this is the first such operation in African waters.

SNEPCo took delivery of the first ROCS from Optime Subsea in 2023 and has been working with the Norwegian company to integrate it into its operations.

The ROCS eliminates the need for both the umbilical, which traditionally connects the surface to the seabed for controlling the tubing hanger in subsea well completions, and the topside hydraulic control unit. This system can cut costs and reduce the amount of deck space required for these operations.

optime subsea Bonga
The ROCS operation at the Bonga field. (Source: Optime Subsea)

Operators using a ROCS can cut approximately 50 tonnes of equipment from their offshore transportation list, according to Optime Subsea. It also means reduced operating time and less HSE exposure on the drill floor, the company said.

When completing subsea wells, the tubing hanger is placed on top of the wellhead, as a seal towards the rest of the subsea well.

Normally the tubing hanger is controlled through a dedicated hydraulic umbilical, which adds a 20-ft to 30-ft control container. When running the umbilical, it is also clamped to the tubing for increased stability.

ROCS replaces these operations by remotely controlling a controls unit toward the wellhead.

ROCS is mobilized in a single basket, prepared and made up onshore, allowing it to be ready to run immediately when offshore, from a rig. The ROCS can be applied to any type of subsea well, Optime Subsea said.

The performance of the ROCS “means that we can perform well completion operations quicker, at lower cost, and with substantially lower CO2-footprint compared to conventional systems,” Justus Ngerebara, SNEPCo lead well engineer, said in a release.

The operation on Bonga 78 was led by Optime Subsea’s operation in Nigeria, supported by personnel from the company’s headquarter in Norway.

In January, Optime Subsea announced it would deliver ROCS for Equinor’s deepwater Rosebank Field in the U.K. North Sea, with operations slated for June 2025.