Chevron, Shell greenlight subsea compression projects

Oct. 1, 2021
Chevron and Shell have sanctioned subsea compression projects in Australia and Norway, respectively.

Chevron and its partners in the Gorgon joint venture have sanctioned the $4-billion Jansz-Io Compression (J-IC) project offshore Western Australia. This is a modification of the Gorgon development, involving construction and installation of a 27,000-metric ton (29,762-ton), normally unattended floating field control station, 6,500 metric tons of subsea compression infrastructure, and a 135-km (84-mi) subsea power cable connected to Barrow Island.

Chevron operates the Gorgon project in partnership with ExxonMobil, Shell, Osaka Gas, Tokyo Gas, and JERA. The Jansz-Io field, 200 km (124 mi) offshore in 1,350 m (4,429 ft) of water, came onstream in late 2015.

J-IC is expected to ensure continued supplies of gas from the Jansz-Io field to the three LNG trains and domestic gas plant on Barrow Island. Chevron expects construction and installation activities to take around five years to complete.

Under a NOK7-billion ($808-million) EPC contract, Aker Solutions will deliver the all-electric subsea gas compression system. This will include a complete compression station with three compressor modules and two subsea pump modules; all-electric control systems and actuators; structures including mud mats, high-voltage electrical power distribution system, several spare modules and equipment; and various associated tooling.

MAN Energy Solutions will supply five Subsea HOFIM compressor units. Three compressor systems will be installed into the subsea modules while the other two will serve as spare units. Hermetically sealed and oil-free, the system uses seven-axes active magnetic bearings and a high-speed motor. According to the company, this design means many components are not required, including the gearbox, lubrication-oil system, instrumentation, and valving as seen on conventional topsides compressor solutions.

Baker Hughes will provide a subsea compression manifold structure including module and foundation, as well as the latest version of its horizontal clamp connector system and subsea controls.

ABB will deliver most of the electrical equipment, both topsides and subsea. The project will combine two of its core technologies – power from shore and variable speed drive long step-out subsea power – for the first time. According to the company, the electrical system will be able to transmit 100 megavolt-amperes over about 140 km (87 mi) and at water depths of 1,400 m (4,593 ft).

Also, A/S Norske Shell and its partners have submitted a development plan for a wet gas subsea compression project at the deepwater Ormen Lange field in the Norwegian Sea. The project is designed to unlock an additional 30-50 bcm of natural gas, increasing Ormen Lange’s overall gas recovery rate from 75 to 85%. The gas is exported through Langeled, a 1,200-km (746-mi) pipeline from Nyhamna to Easington, UK, and linked to the Norwegian gas export system to continental Europe.

OneSubsea will deliver a wet gas compressor system that Subsea 7 will install on the seabed at 900 m (2,953 ft) depth close to the wellheads. The 120-km (75-mi) distance from the onshore processing and export facility at Nyhamna to the installations sets a new world record for subsea compression power step-out, Shell claimed.

Marianne Olsnes, managing director at A/S Norske Shell, said: “Ormen Lange ranks among the lowest carbon intensity fields in Norway, being powered with hydro-generated electricity from the national grid and processed in a closed system at the Nyhamna gas plant.”

Shell operates and holds 17.8% interest the Ormen Lange field. The partners are Petoro (36.4%), Equinor (25.3%), INEOS (14%), and Vår Energi (6.3%).

McDermott to install Whale pipelines

Shell has awarded McDermott a subsea EPCIC contract for the deepwater Whale field development in Alaminos Canyon block 773 in the US Gulf of Mexico. The company will engineer, procure, construct, install, and commission 50 km (30 mi) of pipelines and about 15 km (9 mi) of umbilicals to connect five drill centers to a new semisubmersible production platform. The project will start immediately and is expected to be completed in 2024.

Engineering, procurement, and project management services will be led by the company’s team in Houston. McDermott’s subsea construction vessel North Ocean 102 will install the umbilicals, and the upgraded Amazon will transport and install the rigid pipelines.

Samik Mukherjee, executive vice president and COO of McDermott, said: “This contract, which will take place in a water depth of more than 9,000 ft [2,743 m], is a massive opportunity to demonstrate how the Amazon, with its industry-leading pipelay capabilities, is redefining what is possible within ultra-deepwater construction.”

The Amazon’s upgraded specs are said to enable highly automated operations, the production of hex joints from single or double joints using an onboard multi-joint facility and a pipe hold capacity of 10,000 metric tons (11,023 tons).

Mark Coscio, senior vice president for McDermott’s North, Central and South America region, said: “The technology behind the upgraded Amazon significantly elevates its ability to efficiently deliver safe, quality-driven results. This vessel and its capabilities are a game changer for the industry.”

Shell Offshore Inc. operates and holds 60% interest in the Whale field. Chevron U.S.A. Inc. holds 40% interest. Production is expected to start in 2024.