Subsea sector benefiting from efficiencies, technology development

The consensus view of many industry analysts is the subsea sector is leading the offshore growth cycle, with tree orderbooks swelling to levels not seen in years as operators take advantage of low costs.

David Paganie,Chief Editor

The consensusview of many industry analysts is that the subsea sector is leading the offshore growth cycle, with tree orderbooks swelling to levels not seen in years as operators take advantage of low costs. But this enthusiasm is tempered by a supply chain that is still struggling to make ends meet. Nevertheless, the data is encouraging. Operators ordered 286 subsea trees in 2018 – the highest total since 2013, according to Westwood. The firm expects awards for up to 400 subsea trees this year, with a focus on projects in Brazil and emerging deepwater markets in Guyana, Mozambique, and Senegal.

The improvement in the subsea market can be attributed to project simplification and standardization, but it is also an ongoing commitment to technology development. Inside this issue, Offshore reviews a selection of new and developing technologies that are enabling this subsea revival.

Offshore’s annual subsea poster insert, developed by INTECSEA and Kurt Albaugh, Offshore volunteer poster editor, looks at the evolution and application of subsea processing and boosting systems. It also outlines the various partnerships and alliances that have emerged to bring the technology to market. One relatively new technology that is being used in the field following a lengthy qualification process is subsea compression. The poster details the two major operational compression projects,Åsgard and Gullfaks South Brent. The early success of these two projects has led other operators to evaluate the technology for their fields.

Pseudo dry gas systems, an alternative to compression, are emerging for long-distance tiebacks of 62 mi (100 km) long or greater. This technology, adapted from surface applications, helps overcome the pressure losses due to gravitational effects in long tiebacks and deep waters.

Subsea water treatment is another technology that is maturing through the technical readiness level process. It is also detailed and described on the poster. This emerging technology can reduce space and equipment on the host topsides, eliminate water injection flowlines and risers, and simplify the subsea hardware for the water injection system.

The poster also chronicles the water-depth and tieback-length progressions of subsea boosting systems. As of Feb. 2019, the Shell-operated Stones facility holds the record for the deepest water depth (9,600 ft/2,927 m), and the Murphy-operated Dalmation field holds the record for the longest tieback (22 mi/35 km). Both projects are in the US Gulf of Mexico.

The “2019 Worldwide Survey of Subsea Processing” poster is available inside this issue, and at The accompanying article begins on page 44.

Another critical component of a subsea production system is the power umbilical which distributes power from the host platform to seabed production and pumping systems. CNOOC has sanctioned the first commercial run of a new power umbilical manufacturing method for a subsea tieback project in the South China Sea, writes Jeremy Beckman, Offshore editor-Europe. Aker Solutions’ Oscilay machine will produce the static sections of the Liuhua 16-2 power umbilicals, part of a package of more than 71.5 mi (115 km) of dynamic and static power umbilicals the company is supplying that will connect wells at the deepwater Liuhua 16-2, 20-2, and 21-2 gas-condensate fields to a new FPSO.

The new process has been designed to address the challenges presented by extreme tension loads on umbilicals during installation. An Aker Solutions team in Malaysia is leading the engineering for the Liuhua project, with a team in Mobile, Alabama, responsible for all production. Final delivery is scheduled for 2020.

Jeremy’s full story begins on page 24.

Meanwhile, the uptick in subsea development should improve demand for ROVs and AUVs. Jessica Stump, Offshore assistant editor, reviews the latest technology developments in this space. One example is Flatfish, a resident subsea autonomous vehicle designed to perform subsea asset inspections. Shell awarded Saipem a license to develop the technology which should be qualified for commercial application by 2020.

Jessica’s report begins on page 41.

While the subsea sector is improving, the subsurface seismic acquisition market continues to be challenging for those contractors that remain active, writes Bruce Beaubouef, Offshore managing editor. A number of seismic vessel operators over the past few years have exited the market or were forced to file for bankruptcy. Offshore has refreshed its seismic vessel survey, last published in 2015, to get a feel for the state of the market. Bruce’s seismic vessel report and survey begins on page 20.

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