JIP assesses use of CAN for stronger well foundations

The Industry Technology Facilitator, Oil and Gas Technology Centre, and five other companies are investigating an alternative well foundation technology for subsea exploration and production wells.

Offshore staff

ABERDEEN, UK – The Industry Technology Facilitator (ITF), Oil and Gas Technology Centre (OGTC), and five other companies are investigating an alternative well foundation technology for subsea exploration and production wells.

The joint industry project is in collaboration with Maersk Oil, Nexen, Shell, Siccar Point Energy, another unnamed operator, and TechnipFMC.

It is the first collaborative project between the ITF and OGTC, with the Oil & Gas Authority also acting in an observer capacity and contributing technical support.

The aim is to examine the versatility and robustness of Conductor Anchor Node (CAN) technology, developed by Norway-based Neodrill, as an alternative well foundation for most seabed soils.

The system uses high load-carrying capacity suction anchors to secure seafloor mooring points via a large diameter, relatively short cylinder.

No cement is necessary, and this is said to thereby avoid the risk of typical conductor problems caused by cementing failure.

In addition, the CAN provides a well foundation to be drilled or jetted through, or with a pre-installed short conductor. It has been proven in 17 installations to date with 14 runs in Norway and one on the UK continental shelf.

The initial phase of the CAN-based pre-rig well construction JIP will examine results from these installations and will assess the technology’s suitability in non-clay seabed soils, such as sand and mixed soils.

It will also assess the potential to safely drill out a pre-installed shorter conductor (CAN-ductor) to provide structural support for top-hole well construction.

As a CAN-supported conductor will behave differently to conventional conductors, basic finite element analyses will also be undertaken to demonstrate the system’s load and bending capacities, and fatigue management.

This phase of the project should take six to eight months to complete, with further phases and field trials planned.

Dr Patrick O’Brien, CEO of ITF, said: “Traditional conductors have been used in the offshore industry for more than half a century, with well-known and documented issues around maintaining verticality and providing a solid base to support further well architecture.

“The aim of the JIP is to explore the effectiveness of CAN technology in different well foundations and increase its capabilities in subsea exploration and production wells.”

Another plan is to assess the feasibility of shallow-set CAN integrated conductors to replace conventional deeper-set unsupported technology.

Future phases of the project will look at the use of this technology to help develop small oil pools, facilitate cheaper single production well construction, and for faster and lower cost P&A operations.

Jostein Aleksandersen, CEO of NeoDrill, added: “Compared to the conventional conductor, we already know that CAN demonstrates many advantages including the ability to save rigs time and well costs, as a smaller and more cost-efficient vessel is used for CAN/conductor installation ahead of the drilling unit arrival.”

12/13/2017

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