Background to New Design Manual for Platform Strengthening, Modification and Repair
Authors: Dier A.F. 
Published: October 2008

Eleven oil companies and two regulatory bodies halve funded the creation of a detailed design manual on platform strengthening, modification and repair (SMR)(ll. This manual has Taken three years to prepare, and covers over twenty techniques, including welding (dry and wet), weld improvements, clamping and grouting. The creation of the manual has encompassed generation of new data on clamp systems, to permit undue conservatism to be removed from the design process. Whilst SMR is an important part of offshore engineering, little codified guidance is available, and the various technologies are diverse. The manual, in seven parts, has been created through an exhaustive assessment of all data, information and experience for each technique, including information not in the public domain but released to this project. A detailed recommended practice for each technique has bear developed and, in many instances, the need for new or enhanced guidance has been satisfied. This paper presents the background to the manual, the databases used in its crest ion, the new data generated in the project and the created design guidelines.

Introduction

The continuing requirement for conducting sub sea strengthening, modification and repair (SMR) operations is an impotent and integral part of offshore engineering. The reappraisal of existing retaliations, or the presence of damage, may lead to a requirement for strengthening and/or repair, either at a led comments level or at a global system level. The need for SMR is expected to increase with time as existing platforms age or as a result of platform refurbishment or field development. Such SMR operations tend to be highly engineered, certainty for modems and major works, in order to minimize the high costs associated with offshore worlds.

Safety is an important criterion for deciding the extent and scheduling of any SMR, together with encomia and practical factors. Substantial benefits are achieved by meticulous planning, not only in selecting the most appropriate SMR technique (eg. welding or clamping), but also in giving due attention to the execution of the works (including trick) and the offshore support requirements. The availability of suitable contract, weather window considerations and the urgency of the need for the SMR all play a part in the selection process.

Examination of the status of strengthening and repairsystems reveals that little information is provided in design codes and guidance documents in this area. There is information available; however, it is somewhat scattered amongst various technical publications and papers that may be difficult to obtain. The most complete codified guidance can be found in HSE Guidance Notes(-) but this is not, by itself, sufficient to be able to design say a clamp. Other documents(3'4) referenced by the HSE Guidance Notes are more detailed but these require updating in parts as more recent information is now available.

SMR plays an important, and often critical, part in the safe maintenance and operation of offshore installations. Often, inappropriate, unnecessary or expensive SMR techniques have been deployed, primarily as a result of the diverse nature of this technology and the lack of readily-available guidelines and information.