Decommissioning of Offshore oil and gas facilities: A comparative study between Malaysia practices and international standards

Regulations for decommissioning are bound by international and domestic regulations. There are numerous decommissioning concepts to choose from, such as complete or partial removal, structure severance options which leave behind shell mounds and drill cuttings. However, in several international regulations there appears to be little clarity and/or opposing ideologies. Malaysia and Thailand have accessible resources for decommissioning legislation or guidelines in South East Asia. Nevertheless, they are differences in the regulations of these countries regarding the legal framework, the technical, financial and environmental framework. In this study, the feasibility of existing framework in decommissioning process of offshore installations or structures in Malaysia was studied and compared with international practices. Decision matrix analysis was used to systematically identify, analyse, and rate the performance of relationships between sets of values and information. Moreover, the scale of decommissioning activities over the next years, the data and information obtained were analysed using descriptive statistics approach. The results indicated that Thailand had the best decommissioning regulations because they have strict regulation in decommissioning. Most of the regulations covering the technical section are similar within all countries studied. Finally, recommendations given are from the aspects of frameworks on in-situ full or partial decommissioning, clarity on liabilities and residual risk management, financial security, residual risk funds, workflow optimisation, information management system, and waste management.