Environmental Sustainability and Efficiency of Offshore Platform Decommissioning: A Review

Malaysia has inherited many aged offshore platforms that have reached their decommissioning deadline. Many platforms need to be detached through subsea processes. Although there are good techniques for this, they are usually costly and necessitate a great deal of post-cut checking to ensure complete detachment. Explosive cutting techniques, on the other hand, are cost-effective and reliable for offshore decommissioning as they ensure complete cutting with little uncertainty. Until 2019, statistics showed that almost 35% of offshore platform decommissioning processes involved the use of explosive materials and other mechanical severance options. The method was reliable and cheap, but it had a large environmental impact. During blasting procedures utilizing pressure waves, many sea animal species are threatened, such as fishes, turtles, and dolphins. Depletion of already scarce fish stocks through the unsustainable use of explosive removal should be prevented by reducing the environmental impact of underwater explosives. Moreover, due to safety hazards, vessel and aircraft movement around the explosion zone is prohibited. Therefore, this paper provides a comprehensive review of using a highly vacuum-sealed pile for the explosion to control and reduce shock wave propagation. This effort appreciates the benefits of the explosive cutting technique and reduces its environmental side effects. Our findings indicate an accurate and clean-cut method serving the efficiency of offshore platform decommissioning as well as environmental sustainability. Finally, recommendations for future perspectives have been provided based on the decommissioning of offshore platforms, such as topside removal, planning, time scale, and optimization of available space.