Bearing Blocks Campaign

SubC fabricated and installed the bearing blocks for Tyra Redevelopment as an important part of the Allseas’ removal campaign of the old topsides on TEA and TWA.

The Tyra Redevelopment

The Tyra field comprises the Tyra East and Tyra West platform facilities. The field has been in production for thirty years, and the facilities are suffering from seabed subsidence. New topsides facilities will, therefore, be installed at higher elevations in order to continue production from the Tyra field and associated satellites.

The new topsides facilities will be installed using existing jackets in the Tyra East (TEA) and Tyra West (TWA) fields. The development is being executed in four phases.

SubC was involved in Phase 3: Removal of obsoleted facilities above water (topsides), with fabrication and installation of 16 lifting points for TEA and 8 lifting points for TWA. These lifting points (bearing blocks) are installed at all legs for both platforms and will be used for the topsides single-lift removal by Allseas’ heavy lift vessel Pioneering Spirit. 

SubC’s scope of work

SubC’s scope of work includes fabrication and installation of the lifting points, 16 bearing blocks on TEA and 8 bearing blocks on TWA. The 16 TEA and 4 TWA bearing blocks were installed during Campaign I. The remaining 4 TWA bearing blocks will be installed during Campaign II, in mid-2020.

Prior to the fabrication and installation phase, SubC was responsible for the preparation including project management and engineering.

Preparation and engineering phase

The preparation and engineering phase included the following:

  • Ensure a safe working environment
  • Manage personnel, tools and supervision (including supervision and administration of subcontractors)
  • Co-ordinate, comply and obtain approvals with Certification & Verification Authority requirements
  • Schedule and progress control
  • Preparatory platform surveys
  • Preparation of work packages and as-built reports
  • Participation in relevant HAZID/HAZOP
  • Rigging and lifting plans
  • Procurement of all materials, equipment and services
  • Reporting

In addition, offshore surveys were conducted to verify the condition of existing legs, the position of bearing blocks after tag welding, and final verification of the position of bearing blocks. 

Pre-fabrication phase

Fabrication of bearing blocks included the following:

  • Provision of shop detail drawings, assembly drawings, traceability drawings and weld isometric/matrix
  • Fabrication including assembly
  • Dimensional control
  • Application of coating system including tagging and marking according to specification
  • Supply rigging for each bearing block as per approved lifting and rigging methodology
  • Supply and installation of D-rings and lifting lugs for handling taglines and lift rigging
  • Fabrication and securing for sea transportation
  • As-built drawings as required by the specifications 

Installation phase

The Bearing block installation activities included the following:

  • Mobilization of qualified personnel to perform the work on the platform at day and night shifts
  • Mobilization of required tools and equipment to perform the work on the platform
  • Mobilization of contingency tools and equipment to perform the work
  • Interfacing with the client and third party while on the platform to perform the work
  • Provide all necessary input for the required working permits to do the work
  • Supervise, communicate and operate the bearing block installation scope
  • Perform the bearing block installation scope according to approved procedures
  • The installation required an accurate positioning of the bearing blocks, which included 3D verification of the alignment between the bearing blocks.
  • Demobilization of personnel and equipment

Safety, quality and delivery

During the entire campaign a great focus on safety, quality and delivery in accordance with the schedule has been given. Furthermore, all involved parties have participated in broad and effective cooperation in order to execute a complex offshore campaign, which resulted in a campaign finalized two weeks prior to planned.

For the fabrication and installation phase, a total of +10.000 hours has been executed without any recordable incidents, without any spills and without any HIPO’s.