Dover Development, US Gulf of Mexico

Dover is a deepwater oil field project being developed as a subsea tieback to the Appomattox production hub in the US Gulf of Mexico.

Shell Offshore, which has 100% working interest in the field, took the Final Investment Decision (FID) for the project in March 2023.

The Dover Development is expected to start production between late 2024 and early 2025. It will produce up to 21,000 barrels of oil equivalent per day (boe/d) at peak.

Shell’s investment in Dover Project is aligned with its long-term commitment to the US Gulf of Mexico as the company seeks to pursue energy-efficient and high-return upstream investments.

In 2022, the company took FID on another discovery called Rydberg, which will also be tied back to Appomattox.

Dover location details

The Dover Deepwater Project is located within Mississippi Canyon in the US Gulf of Mexico. The site is around 170miles offshore southeast of New Orleans in Louisiana.

Water depth in the region is approximately 7,500ft.

Discovery

The Dover deepwater field was originally discovered in 2018. It marked Shell’s sixth discovery in Norphlet geologic play.

The discovery well, drilled in Mississippi Canyon Block 612, encountered more than 800 net feet of pay (244m). It was drilled to a total vertical drilling depth of 29,000ft (6,780m).

Dover development details

The development concept of the Dover project will include a subsea tieback to the Shell-operated semi-submersible floating production platform Appomattox production hub.

It would include two production wells, which will be connected to Appomattox via a 17.5-mile flowline and riser.

Appomattox Production Hub Details

The Appomattox production hub is operated by Shell with 79% working interest. The remaining 21% working interest is with China National Offshore Oil Corporation (CNOOC) International.

The construction work on the production hub commenced in July 2015 at the Samsung Heavy Industries’ shipyard in South Korea.

In October 2017, the hull of the Appomattox platform arrived in Ingleside, Texas, the US, for topsides integration phase.

The hull of the platform is the largest four column structure that has been built by Shell. It measures 112.1m (368ft) from the edge of each column.

The structure is 53.4m (175ft) high, weighs 42,700 metric tonnes and has a total displacement of 125,000 metric tonnes.

It will support four primary topsides modules including the process, utilities, power, and living quarters. The hull will support the riser pull-in bridge, production, water injection, and export risers.

With a design life of more than 30 years, the Appomattox production platform can produce 240,000 bbls/d.

After the integration of the topsides and the hull, the Appomattox platform was transported to the production site in the Gulf of Mexico.

In the Gulf of Mexico, the platform was moored up and then connected to the subsea pipelines and equipment.

As a floating production system (FPS), Appomattox began production in 2019. The system was designed to operate as a long-term hub to tieback existing fields and future discoveries.

Appomattox is the largest floating production platform operated by Shell in the Gulf of Mexico.

Contractor Involved

In March 2023, Shell awarded an Integrated Engineering, Procurement, Construction, and Installation (iEPCI) contract to TechnipFMC for Dover Deepwater Project. The contract award is valued between $75m and $250m.

As agreed, TechnipFMC will deliver the subsea tree systems along with providing engineering, procurement, construction, and installation services for the umbilical, riser, and flowline systems.

TechnipFMC also supplied and installed the subsea production systems for Appomattox platform.