Requalification of Offshore Jacket Structures in Malaysian Waters

Abstract

Currently there are more than 200 existing offshore structures in Malaysian waters. These structures were designed for life of 25 years however majority of these structures had exceeded this design life. Throughout the operating life these structures had been subjected to modification/extension of structural serviceability to accommodate additional weight and damage associated with South China Sea tropical storms & seasonal monsoons and deteriorations of the structure materials due to aging. This had pointed that some of these structures may not meet today requirements for integrity & reliability. In order to ensure the safety of these structures are continuously intact there is a need for reassessment on the ability of these older structures to perform original function and accommodate new requirement as per corporate expectation. A sophisticated and rational requalification procedure has been established to ensure the safety is maintained for life extension. The present paper will focus on the established reassessment procedures incorporating the Structural Integrity Management (SIM) processes. The issues with regards to acceptance criteria will be elaborated and methods in performing the assessment activities are addressed in stepwise manner. The paper will also highlight several issues inherited in the adopted processes and provide some new developments to support the process in addressing the constraint faced. The adoption of the established approach has enabled the requalification of these existing structures satisfies structural integrity compliance and has resulted in: No costly strengthening, No costly underwater inspection, No de-rating of facility, No prevention of further/future upgrading, Extension of Platform life for continuous production/operation.

Data science application in structural integrity analysis of fixed offshore jacket platform

“…It is compared to [12][13] and [14] recommendation as to the Malaysian authority. The reference line by ISO 19902 in Figure 9 is the outcome from a design perspective is L2, which is under the best condition.…”

“…Following the development of the method, conclusions regarding the result of POF obtained using the Python algorithm may be derived by comparing it to the result calculated using Equation ( 3) and ( 6) against the [12] target reliability, [13] inspection interval and [14] as authority point of view. It is essential to assess if the POF results are in good condition from a design perspective, inspection interval, and risk to consider.…”

Structural Integrity of Fixed Offshore Platforms by Incorporating Wave-in-Deck

“…To avoid overestimation, studies performed by Mat Soom et al [39] and Ayob et al [40] carried out the RSR calculation up to the bottom of the steel structures by limiting the wave crest height. By doing so, they might overly underestimate the RSR in the event that the platform had the capacity to take a higher environmental load.…”