Modular Well P&A Integrated Support and Operation Services Concepts

(Champion: Spirit Energy) – October 2020

Shallow gas reservoirs drilled at a 60-degree angle from the surface in the 1980s pose Spirit Energy a unique decommissioning challenge, resulting in a new design modular plug and abandonment unit which can be deployed across Spirit Energy’s decommissioning portfolio.

Although they are uncommon, Spirit Energy has 28 such ‘slant wells’ in Morecambe Bay, with 5 on their DP3 and 4 on their DP4 facilities - the first platforms in the field to reach the end of their productive lives. Faced with this challenge, Spirit Energy engaged Herrenknecht, a German technology firm, and the project team designed and modified a bespoke modular rig unit with a hydraulic mast that can be tilted between vertical and slant wells. The system was built and installed on the DP4 platform where it safely and successfully abandoned all 6 wells before moving onto DP3 to abandon a further 6 wells to repeat the operations.

The modular rig was deployed from a Jack-up Drill Rig which provided services and interfaces to support the rig operation on DP3 and DP4. This was useful in completing a wider campaign in the East Irish Sea including subsea well abandonments.

The challenge presented was to enhance concepts for phase 2 for the abandonment of the 36 remaining live wells at DP1, DP6, DP8 and DPPA.

What the opportunity was looking for:

1.     In enhancing concepts for phase 2 for the abandonment of the 36 remaining live wells at DP1, DP6, DP8 and DPPA, on behalf of Spirit Energy, ideas were invited on:

How the deployment of the modular well P&A unit could be enhanced and evolved to drive further innovation and efficiencies for Phase 2 abandonments, commencing with DP1?

Some examples could include:

·       Innovative integrated service contracts with single interface to Spirit.

·       DP1 walk to work from AP1 eliminating / minimising marine spread requirements.

2.     As a secondary prospective alternative, Spirit Energy also sought accommodation/crew support services, in conjunction with the above, for the abandonment of Normally Unmanned Installations (NUIs) DP6 and DP8.

This could be by deployment of the unit from a standard work barge or well intervention barge removing the requirement for a Jack-up Drill Rig.