Self-Elevating Unit Conversions

Mobile Offshore Production Units (MOPU) converted from existing self-elevating unit (SEU) are often considered for shallow water production fields. They offer opportunities for fast track development in comparison to new construction of fixed jackets, and are typically able to be deployed on site without specialized offshore installation vessels.

ABS Guide for Conversion of Self-Elevating Units to Offshore Installations

This Guide, in conjunction with the ABS Rules for Building and Classing Offshore Installations (Offshore Installation Rules, or OI Rules) and the ABS Rules for Building and Classing Mobile Offshore Drilling Units (MODU Rules), provides guidance on the classification requirements for converting self-elevating units to offshore installations. 

These publications address the required assessments for the structure and foundations of the installation. The below can be included within ABS’ scope of classification upon request:

  • Jacking System
  • Marine & Safety Systems
  • Topside Systems

Application of Statutory Regulations

The owner has the option to request ABS for statutory services on behalf of the flag administration and coastal state authority. The degree of a MOPU’s compliance with statutory regulations of the applicable flag state or coastal state may differ from project to project. ABS may only need to issue a single trip load line certificate if the unit is wet towed to the installation location, or there may be additional statutory requirements to address. ABS provides assistance in defining the necessary certifications for a given operating location.

ABS can provide the following services to assist with the conversion of self-elevating units into mobile offshore production units:


  • Design Review - These requirements cover design considerations, foundation design and structural analysis specific to the production site. 


  • Fatigue Assessment - A spectral fatigue analysis technique is recommended to calculate the remaining fatigue life of a MOPU taking into consideration the existing fatigue damage due to unit’s past service.


  • Foundation Design - The classification of the MOPU is dependent on evaluating the installation for the site-specific soil conditions.


  • Surveys during Conversion - Conversion surveys are carried out by an ABS Surveyor attending the conversion shipyard in accordance with the ABS Offshore Installation Rules and the MODU Rules.


  • Installation Survey and Commissioning - The installation survey is carried out offshore by an ABS Surveyor, in accordance with 5-1-2/21 of the Offshore Installation Rules. 


  • Survey After Construction - Annual and other periodic surveys need to be performed by an ABS Surveyor to maintain the classification of the MOPU as an Offshore Installation.