CORROSION MANAGEMENT SYSTEM AND ITS APPLICATION STUDY FOR OFFSHORE GAS PIPELINE SUBJECTED TO TOP-OF-LINE CORROSION RISK

• Main Author: IKHSAN (NIM 23105004), ILMI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8194
• Institution: Institut Teknologi Bandung

In oil and gas industry, corrosion management system often have been looking upon department which manage the some routine activities related to design, inspection and maintenance of industrial equipment. This perception may arise in the absence of applicative method which can integrate corrosion management concept, risk management and optimal corrosion analysis performed by corrosion engineers. Whereas, corrosion management system should be envisaged as a proper methode in order to give profit and benefit for environment, productivity, safety and quality. Therefore, this thesis is purposed to develope practical method of an integrated corrosion management system, with an application study for offshore gas pipeline subjected to top-of-line corrosion in an Indonesian gas.<p>Methodology used for this study is done through a sequence of reliability based corrosion management analysis which consists of corrosion management analysis, risk management and corrosion analysis. Reliability data analysis is one of some important parts in corrosion analysis optimalization. Raw data, namely wall thickness and corrosion rate resulted from intelligent pigging, then be processed with first order second moment (FOSM) method to get reliability index, reliability value and probability of failure. Based on probability of failure and consequences of failure criteria standard adopted from DnV, pipeline risk then be mapped in risk matrix 5x5. Ploting reliability data and probability of failure to year of operation, a "reliable condition" or failure-free estimation could be determined as long certain period. This result then is compared with deterministic calcullation as per ASME B31G to get more efficient reinspection schedule.<p>For the pipe which was observed, the pipe was in "low risk" relative area. It was concluded, the improvement of corrosion inhibitor performance from non volatile type to volatile type becomes key role for optimalization of existing pipeline performance. Besides, external corrosion protection can be optimalized with knowing actual condition through sea line survey. Reinspection schedule is in 2012 based on reliability method and in 2010 based on deterministic method per ASME B31G. However, to get optimal performance, there should be performed further research of proper internal coating on new pipeline design.