Traditionally, subsea systems have used relatively low-speed communications links of around 1.2 to 9.6 Kilobits/sec between surface and subsea facilities. As a result, a certain amount of autonomy has been necessary within the subsea equipment to maximize the available bandwidth for process monitoring data. This typically took the form of an automated valve and choke controls.
A newly introduced subsea module has been designed with a different approach. By using optical communications capable of 1 Gigabits/sec and new copper-based communications technology operating at up to 5 Megabits/sec, it is now possible to move this functionality from the subsea module to the surface equipment and to fully integrate it with the topsides, reducing the complexity of the subsea software.
Innovation takes shape
Original content:
The VetcoGray SemStar5, a fifth-generation subsea electronics module, offers new levels of open architecture IP-enabled communication capabilities. (Image courtesy of GE Oil & Gas)
Responding to industry requirements for standardization and expandability in subsea production control systems, GE Oil & Gas developed the VetcoGray SemStar5, a fifth-generation subsea electronics module. The first application of the new technology will be for StatoilHydro’s Tordis Vigdis Controls Modification (TVCM) project in the North Sea, west of Norway, in about 656 ft (200 m) of water.
Featuring a modular design approach, SemStar5 offers new levels of open architecture IP-enabled communication capabilities. The module provides the infrastructure to support the higher bandwidth requirements of modern instrumentation while also offering high reliability. The design draws on VetcoGray’s 25 years of experience with subsea electronics and more than a century of experience in electronics and communications.
SemStar5 is designed as an open architecture, ethernet-based hub or router using TCP/IP protocol, which provides access to third-party subsea instrumentation to transport data from the seabed. With this capability, the new module is a key enabler for the connectivity of subsea facilities — including subsea processing and boosting — to the digital oilfield technologies. Used as a data router hub, the SemStar5 provides a wide variety of subsea communications strategies to match field development needs, including providing long and ultra-long offset capability for direct “subsea-to-beach” tiebacks from large subsea gas reservoirs. These offsets can be as long as 311 miles (500 km).
The same SemStar5 platform is used in the “traditional” role for a subsea electronics module (SEM) as the micro-controller for a tree or manifold-mounted subsea electro-hydraulic control module.
Designed as a structured subsea solution, SemStar5 can be constructed in one-, two- or three-bay configurations that cover any subsea field development. Enhanced reliability is achieved with thermal management and modeling integral to the design, onboard diagnostics, and fault tolerant input/output. The robust mechanical construction is designed to meet and exceed shock, vibration, and temperature cycle requirements of ISO 13628-6 2006.
GE was awarded a “Spotlight on New Technology Award” at the 2009 Offshore Technology Conference for its development of SemStar5. The award recognizes new and innovative technologies that have significant impact on offshore E&P sectors.
Putting the module to work
The Tordis and Vigdis fields lie offshore mid-Norway in the Norwegian North Sea at 656 ft (200 m) water depth. (Image courtesy of Statoil)
In June 2009, GE Oil & Gas announced that it had been awarded a US $70 million contract from StatoilHydro to upgrade a suite of subsea control systems for the company’s TVCM project. This project will serve as the commercial launch site for the SemStar5 technology.
The Vigdis oil field lies in block 34/7 in the Tampen area of the Norwegian North Sea and came onstream in 1997. In addition to the main structure, this field comprises the Borg North-West formation, which came online in 2003, and the Vigdis East formation, which began production in 2004.
Vigdis has been developed with subsea installations tied back to the Snorre A platform 4.3 miles (7 km) away for processing. Gas separated from the main Vigdis structure is injected into the Snorre field, while gas from Borg North-West and Vigdis East is piped from Snorre A via the Statpipe/Norpipe system. Stabilized oil is transported by pipeline to Gullfaks A for storage and export.
The Tordis oil field also lies in block 34/7 and came onstream in 1994. In addition to the main Tordis structure, the development embraces the Tordis East (1998), Borg (1999), and Tordis South East (2001) fields. All of these discoveries have been developed with subsea installations. At present, water is being injected into the reservoirs to maintain pressure. Oil from Tordis is piped to the Gullfaks C platform 6.2 miles (10 k) away for processing, storage, and export. The former Saga Petroleum Co. became the operator for license PL 089 when the license was awarded in 1984. Norsk Hydro took over operatorship after acquiring Saga in 1999. On Jan. 1, 2003, Statoil took over operatorship, and on Oct. 1, 2007, StatoilHydro assumed operation.
First global deployment
Key objectives for the initial installation are higher subsea reliability, extended service life, and improved environmental monitoring. In addition, the “plug and play” expandability of this open architecture system allows the possibility, over the extended plateau production period for the field, of adding more sophisticated — and as yet undeveloped — sensors for facility and produced-fluid condition monitoring.
Such systems become an ideal platform for production optimization algorithms as the subsea facilities become part of the integrated process control of the upstream plant.
The scope of the contract will be executed under the subsea production systems frame agreement that was awarded to GE Oil & Gas by StatoilHydro in autumn 2007.
The SemStar5 module is being developed and manufactured at the GE Oil & Gas facilities in Nailsea, UK, along with VetcoGray ModPod subsea control modules. The modules will be shipped to the project site offshore Norway for installation in 2010 and 2011.
The TVCM project will further benefit from the newly upgraded GE Oil & Gas test and assembly facilities at Dusavik, Stavanger, Norway, with the development of intervention tooling mainly being carried out from the Dusavik site.
Recommended Reading
Formentera Joins EOG in Wildcatting South Texas’ Oily Pearsall Pay
2025-01-22 - Known in the past as a “heartbreak shale,” Formentera Partners is counting on bigger completions and longer laterals to crack the Pearsall code, Managing Partner Bryan Sheffield said. EOG Resources is also exploring the shale.
E&Ps Pivot from the Pricey Permian
2025-02-01 - SM Energy, Ovintiv and Devon Energy were rumored to be hunting for Permian M&A—but they ultimately inked deals in cheaper basins. Experts say it’s a trend to watch as producers shrug off high Permian prices for runway in the Williston, Eagle Ford, the Uinta and the Montney.
Sliding Oil Prices Could Prompt Permian E&Ps to Cut Capex
2024-12-03 - A reduction in the rig count would also slow the growth of natural gas output from the region, benefitting gassy Gulf Coast players, according to Enverus.
Shale Outlook: E&Ps Making More U-Turn Laterals, Problem-Free
2025-01-09 - Of the more than 70 horseshoe wells drilled to date, half came in the first nine months of 2024 as operators found 2-mile, single-section laterals more economic than a pair of 1-mile straight holes.
Devon, BPX to End Legacy Eagle Ford JV After 15 Years
2025-02-18 - The move to dissolve the Devon-BPX joint venture ends a 15-year drilling partnership originally structured by Petrohawk and GeoSouthern, early trailblazers in the Eagle Ford Shale.
Comments
Add new comment
This conversation is moderated according to Hart Energy community rules. Please read the rules before joining the discussion. If you’re experiencing any technical problems, please contact our customer care team.