Busy work

Introducing a new FPSO into a brownfield while overhauling the subsea infrastructure led to a complex multi-year SIMOPS campaign for Technip. Elaine Maslin reports.

A GIS image (above) shows the complexity of the SIMOPS at Quad 204, with the photo showing the same view from the surface (below). Images from Technip.

SIMOPS, or simultaneous operations, has been the name of the game on the subsea decommissioning and installation campaign on BP’s Quad 204 project.

Technip is the main contractor and had the task of removing and then installing new subsea infrastructure in a complex, multi-year, multi-vessel campaign.

With five drill centers, and gas lift and water injection planned, a lot of subsea infrastructure is needed on Quad 204. In addition to its own vessels, this year Technip has also had to contend with the semisubmersible drilling rig Deepsea Aberdeen starting operations in field as well as the Island Constructor offshore construction and light well intervention vessel. At any one point, there has been up to 10 boats working in the field.

“In terms of vessels, this is one of the busiest projects we have worked on. We typically had three in the field last year. This year it has been five, six, and even seven at one point in early March,” says Richard Wiley, project director for Quad 204, at Technip.

Some 18 risers were recovered and 14 moorings. For the installation campaign, Technip supplied 23 new risers, as well as the associated DMAC connectors and buoyancy modules, 78 jumpers and 15 corrosion resistant alloy (CRA), metallurgically bonded clad pipe pipelines. Most of the manifold, controls, jumpers, connectors were provided under free issue from BP suppliers.

In field, Technip’s scope is to reconfigure and install the jumpers, install fly to place connections for new structures and five static umbilicals, as well as installing 15 new CRA pipelines, the new Glen Lyon FPSO, 23 risers, 99 flexible pipes and 20 moorings. What’s more, it made its largest ever bend stiffeners for the project, through Aberdeen based Balmoral Group.

To handle the DMAC riser connection system tooling, BP also commissioned two new tooling stores, given free issue to Technip, such is the scale of the project.

Richard Wylie.

In total, the project will have involved about 2500 vessel days over four to five years, Wiley says, with some 800 people within Technip having charged time to the project. “The challenge for us was the scale of the project,” he says. “The size and scale of the project had ramifications on how to organize the project team. The weather and limited construction season West of Shetland also had to be taken into consideration and because of the weather, the design is for a 100-year wave height of 31m, which makes everything that bit bigger. It is also a brownfield project, which means it’s very crowded, so you have to be very careful where you put stuff.”

To handle the multiple work streams, Technip split the project into three, with about 100 people in the project team. The first work stream was dedicated to flexibles, the second split into two construction teams, one for seabed and one for in the water column, and the third for HSE, QHSE and contracts.

Key to the SIMOPS has been using GIS to track all the boats and remotely operated vehicles (ROVs) in the field. With it, the operators can all see where all the other vessels and even the ROVs being used are.

The campaign started in 2013-14, with field disconnection and the old Schiehallion FPSO removed. The FPSO mooring system was recovered and wet stored and flexible jumpers and fly to place connections disconnected and recovered.

In 2014, the installation of the new field infrastructure started, with a new mooring system installed, new structures, two static umbilicals and flexible jumpers laid down, eight CRA-clad rigid pipelines installed. The wet store riser hold back installed.

In 2015, the program continues with another seven CRA-clad pipelines manufactures and installed, 21 risers, three static umbilicals, and deployment and tie-in of control jumpers and flying leads, with the drill centers the key focus ahead of drilling starting this year and the arrival of the Glen Lyon FPSO. Decommissioned control jumpers will also disconnected and recovered. In 2016, the last remaining structures will be installed.