Life time extension of offshore platforms
INTRODUCTION - LIFE TIME EXTENSIONS OF OFFSHORE PLATFORMS
Existing offshore platforms undergo an annual inspection and testing, as laid down in the long-term inspection plan. In some cases, certification is required in the form of a Life Time Extension (LTE).
An LTE applies when checking the original platform design, extending its lifespan or if damage has occurred to the platform. Bureau Veritas has more than 30 years of experience in conducting LTE Assessments.
The steps within the Life Time Extension Assessment are similar to those of a design review for a new offshore platform. An LTE study of the customer must prove how many years the platform can still remain in use, safe for people and the environment. In this study, the customer must include the inspection history and pay attention to the following aspects:
- Historical data on addition, change and removal of parts
- Historical data on incidents with damage and the associated repairs
- Thickness and extent of biological growth and possible removal thereof
- Water depth measurement, observation of erosion at the foundation and cathodic protection
After this review, the assessment process continues with the structural design review. It covers the following topics:
- Assessment list of applicable norms, standards and regulations
- Assessment report on weight checks
- Assessment, comment or reassessment of structural design criteria, including geotechnical and environmental data
- Assessment, commenting or revaluation of in situ calculations for operational and extreme conditions for the jacket, foundation and main platform, including an assessment of the pillar penetration and analysis of material voltages.
- Assessment, comment or reassessment of the jacket's fatigue calculations.
After successfully completing both reviews, Bureau Veritas issues three documents, the Report of Lifetime Extension, the Certificate of Structural Lifetime Extension and a new Certificate of Fitness (CoF).