SUBSEA/SURFACE SYSTEMS

Dec. 1, 2006
Statoil has installed a new subsea template in Norne field of the Norwegian Sea, and one of its wells is on production.

Norne field subsea template installed

Statoil has installed a new subsea template in Norne field of the Norwegian Sea, and one of its wells is on production. Statoil said a total increased recovery of 10 MMbbl of oil should result from the new equipment as production from the new template will prolong the field’s life.

The four-slot seabed template, designated K, is a typical subsea satellite development tied in to existing infrastructure. Acergy Norge installed the K template and tied-in the pipes and control cables to existing subsea templates. The subsea equipment is by FMC Technologies. The K template was installed in September 2005 as a continuation of activities on the Urd field, comprising the Norne satellites, Stær and Svale. The remaining work was done this summer and autumn.

The other well was scheduled to be commissioned by the TransoceanArctic rig, and production from this well was expected at the end of November. The development solution allows for the drilling of two more wells from the K template.

An artist’s rendering of the subsea template for Norne field.

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“Statoil’s ambition is to maintain a production level of 1 MMboe/d on the Norwegian continental shelf until 2015,” said Terje Overvik, executive vice president for Exploration & Production Norway. “Improved recovery on Norne will help us achieve our ambitious targets and is in line with the goal of increased exploitation of existing infrastructure.”

Ability Group acquires SeaVation

The UK-based subsea excavation and pipeline trenching service company SeaVation Ltd. was acquired by Norway’s Ability Group ASA. SeaVation will continue to operate under its own name from its Aberdeen headquarters. SeaVation specializes in hydrodynamic subsea excavation, and provides excavation, pre-sweeping, trenching, backfilling, placement, and dredging services.

“SeaVation is an ideal fit for AGR Subsea,” says AGR CEO Sverre Skogen. “The company continues to develop and improve the technology and to introduce new tools and techniques that are highly innovative, satisfy key requirements of the rapidly growing deepwater trenching market, and are complementary to existing AGR subsea operations.”

“We see this as a stepping stone,” says Nick Sills, one of SeaVation’s founders. “SeaVation will be able to move forward on an even stronger corporate, financial, technological, and managerial platform. This will be good news for our clients, who will see the advantages of our combined operating experience and financial strength, and our personnel, who can look forward to extensive opportunities within a larger group.”

Petrobras contracts subsea system from FMC

Petrobras has contracted the subsea gas production system for Mexilhão field to FMC Technologies Inc. The $122-million contract covers six subsea trees, two subsea manifolds with multiplexed controls, and related subsea systems. The Mexilhão field is in the Santos basin, São Paulo, about 160 km (100 mi) offshore in water depths of 320 to 550 m (1,050 to 1,800 ft). Specifications called for equipment rated for 10,000 psi and 300°F. It will be manufactured at FMC Technologies’ Rio de Janeiro facility for delivery in 2008.

Subsea trenching machine tested

A successful test of what SMD Hydrovision calls the most powerful subsea trenching machine in the world was completed in the Tyne River adjacent to SMDH’s Turbinia Works.

The 2 MW pipeline trencher was designed for the Sea Trucks Group based in Nigeria with contributions from Shell Petroleum Development Co. Nigeria and Hyundai Heavy Industries to handle two new pipelines for the Bonny Island Terminal. The 36-in. and 48-in. pipelines will be installed and buried between two existing, live lines from the beach to offshore.

The 2MW pipeline trencher by SMD Hydrovision is lowered into the water for testing.

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To meet that requirement, SMDH developed a self-contained jetting and dredging machine, which runs on rollers on top of the pipeline. The machine fluidizes the soil around and under the pipe, and removes it using dredge pumps, leaving a narrow trench under the pipeline with limited impact on the environment.

The machine is supported by the pipe and buoyancy tanks. These can be lowered by remote control to serve as skids in the surf zone. The machine is bidirectional, enabling it to make multiple passes between the beach and the support barge without being turned around. The 750-m (2,460-ft) power umbilical allows it to work at a distance from the barge.

The machine has SMDH’s distributed vehicle control system to monitor and control the trenching process. Power and telemetry are transmitted via a single armored umbilical to containerized control and power vans on the support barge.

Wireless technology aimed at North Sea operations

The UK Department of Trade and Industry is reported by the Sunday Herald to be planning a £1.1 million ($2.17 million) award to a consortium to develop subsea wireless communications for turbulent seas and great depths.

One part involves a digital radio frequency system to allow a vessel to remain in contact with a wellhead in turbulent seas.

Another part of the program involves an underwater docking system for autonomous unmanned vehicles (AUVs) to make them more applicable to North Sea operations.

In this scheme, a wireless radio frequency system would transmit broadband data to and from AUVs at the subsea dock to reduce the need for surfacing to download data gathered on the seabed or by seismic monitors.

The last part of the study is aimed at developing better subsea pipeline leak tracking.

“Many pipelines in the North Sea are getting quite old. They were designed for a 30- to 40-year lifetime. Pipeline monitoring is becoming increasingly important. But one of the challenges is getting sensor data up and down the pipe and back up to the surface,” says Brendan Hyland, founder of Wireless Fibre Systems, one of the consortium members.

Tritech and Insensys, both of Aberdeen, are the other two members.

Gene Kliewer, Houston