| dc.description.abstract | Abstract
In the coming decades, burning fossil fuels will still be necessary, therefore Carbon Capturing and Storage (CCS) can aid in reducing greenhouse gas emissions. There are multiple technologies that can capture CO2 from various sources and transport it to a permanent storage site, like depleted gas fields or saline aquifers, or deliver it for usage.
In the carbon capture and storage value chain, CO2 transport, and injection are regarded as the intermediate chain. Depending on the location and scale of the emitter, CO2 may be delivered either through pipeline or by sea carriers. This project considers offshore offloading of CO2 stored in a ship as the best option for moving low to medium volumes of CO2 across long distances. Meanwhile looking at CO2 shipping as a safe, dependable, and adaptable approach, its technological viability in relation to other transportation methods is considered.
The primary purpose of this research was to conduct a qualitative assessment of Leda Flow in order to simulate CO2 offshore offloading using subsea network systems injecting CO2 into four wells. CO2 injection contributors can optimize their CO2 injection process by employing simulation findings from different scenarios in this project. Various chapters were built in this project to achieve the objectives.
In the introduction, the CCS value chain was introduced initially. Then, various CO2 transportation and offloading technologies were introduced and compared. Different operational ranges in CO2 transportation were described in this section based on the purpose and availability of technology.
Another important aspect that was investigated in this study was thermophysical characteristics of CO2 and its variation with pressure and temperature because of phase transition. CO2 is operated at various pressures and temperatures throughout the CO2 shipping chain, so a thorough understanding of CO2 phase behavior was essential since CO2 pressure, temperature, and heat transfer are always changing due to pressure loss and heat transfer across the entire chain.
This project investigated CO2 pressure, temperature, and phase behavior when CO2 flowed through riser, flowlines, and wells using heat transfer and pressure loss simulations. The effect of system parameter on injectivity was investigated in Chapter 3 through sensitivity analysis of injection parameters such as pressure and temperature, as well as subsea injection system design. The first part of the simulations, which used Leda Flow as the multiphase flow simulator, revealed impacts of various factors on injectivity and flow distribution in networks while taking flow stability and flow assurance issues into account.
In addition to steady-state CO2 injection scenarios, this research investigated transient scenarios such as shut down and startup. To do this, the influence of operating time was investigated, and the causes of different responses by the injection system were investigated.
Finally, recommendations based on the simulations' findings were made, with the goal of achieving even flow distribution and lowering pressure at the discharge to reduce the necessary power for pressurizing CO2. | |