1 CHAPTER I INTRODUCTION I.1 Background Over an extended period of time, there has been a noticeable increase in the average temperature of the Earth's surface. This happens due to the greenhouse effect in relation to the quantity of carbon dioxide (CO 2) gas emitted and subsequently retained within the Earth's atmosphere. The most common pollution produces by humans is carbon dioxide (CO 2) which is the main cause of greenhouse gas (Peletiri et al., 2018). According to the International Energy Agency (IEA) report in 2020, the aggregate indirect greenhouse gas (GHG) emissions stemming from oil and gas operations account for around 15% of the overall GHG emissions. One potential approach for mitigating the release of carbon dioxide (CO 2) into the atmosphere and addressing the consequences of global warming is the implementation of Carbon Capture and Storage (CCS) technology. Carbon Capture and Storage (CCS) is a method that is capable of capturing and preserving up to 90% of CO 2 emissions from major point sources like fossil-fuelled power stations (Leung et al., 2014) The implementation of Ministerial Regulation No. 2 of 2023 by the Indonesian Ministry of Energy and Mineral Resources, which pertains to carbon capture and storage, is expected to contribute to the fulfillment of the national commitment in addressing the issue of global climate change. This commitment aligns with the objectives outlined in the United Nations Framework Convention on Climate Change (UNFCCC) Paris Agreement. In several previous studies, CO 2 storage will be focused on pure CO 2 injection in mature oil and gas fields. High prices, limited storage capacity, public acceptability, and regulatory frameworks all take on challenges to CCS deployment with the most expensive pieces of equipment from surface facility and pipeline. Some of these efforts were successful and most of the pure CO 2 was transported using pipes in the liquid phase and had no impurities. However, if the CO 2 injected into the formation still contains effluent gases which become impurities in the injected fluid such as CO, O 2, H2, SOx, and NOx, it will most likely become a problem because it is not suitable for reservoirs and has the properties different from pure CO 2 after injection (Mohitpour et al., 2012). 2 The transport method used in this study is pipeline transport with an estimated pipeline length of 202 km. Several factors need to be considered in transporting CO 2 such as operating pressure, operating temperature, CO2 composition, corrosion rate, etc. In transport to the injection point, CO 2 will be most economical if it is carried out in supercritical conditions, whereas in these conditions, CO 2 has the properties of a gas phase but is in the "form" of the liquid phase.