International Journal of Greenhouse Gas Control最新文献

Carbon capture and storage (CCS) is a promising technology for mitigating greenhouse gas emissions and achieving carbon neutrality. In the CCS value chain, CO₂ pipeline transportation is essential in linking emission sources to storage sites. For instance, the design of CCS transportation requires the consideration of factors such as distance, CO₂ vol, and construction costs while addressing phase changes, corrosion, and optimizing the pipeline network to ensure cost efficiency. Furthermore, involving the meticulous consideration of operational conditions and impurity effects, flow assurance is vital to ensure the safe and efficient transportation of CO₂ through pipelines. Advancements in network optimization techniques and sophisticated modeling have contributed significantly to the realization of CCS projects worldwide. This review investigates essential aspects and relevant studies for effective CO₂ pipeline transportation within a comprehensive framework of CCS infrastructure and its life cycle. State-of-the-art studies have been extensively reviewed and, where necessary, tabulated and plotted for summarization. Via comprehensively understanding and proactively addressing the inherent challenges and considerations associated with CCS transportation, foundation for effective CCS implementation can be laid.

Understanding how in-situ mineralization of CO₂ affects the porosity, permeability, and pore network of the host rock is critical to assessing the viability of basalt reservoirs as carbon dioxide repositories. Here, we present an x-ray translucent environmental cell which allows carbon mineralization, and other fluid–rock reactions to be studied in real time and on the grain scale under simulated geological reservoir conditions using microtomographic imaging. The cell operates autonomously from a CT instrument and is periodically quenched and relocated for scanning, enabling long duration operando experiments. Samples are reacted under controlled conditions of chemistry, temperature, and fluid pressure. Porosity and permeability changes are tracked through digital image analysis of successive CT scans. Samples are fully recoverable, allowing for a suite of post-mortem analyses. The cell design uses readily available materials, can sustain long-term operating temperatures of up to 200 °C, and is reproducible at low cost with a centre lathe and a mill using a conveniently equipped mechanical workshop.

Accidental leakage poses a significant safety concern for carbon capture, utilization, and storage (CCUS) projects. Understanding the near-field characteristics of leakage is essential for dispersion studies, safety distance calculations, and risk assessment of emergency response to a pipeline leakage. This paper presents a small-scale CO₂ pipeline leakage experiment designed to investigate the transient characteristics of near-field parameters, including temperature, pressure, and jet structure. The study also analyzes the effects of factors such as initial pressure, initial temperature, and leakage orifice diameter on the transient characteristics of the near-field. The experimental results demonstrate that lower initial temperatures lead to higher near-field pressure peaks, while larger orifice diameters result in larger near-field pressure peaks. Furthermore, a larger hole diameter combined with a lower initial temperature and higher initial pressure leads to the negative pressure region in the near-field being farther away from the leakage opening. In the liquid state, the near-field temperature is lower compared to the gaseous state due to the strong liquid-gas flash evaporation. When different orifice diameters are used for depressurization, larger diameters cause a more significant drop in near-field temperature. The study also reveals that the effect of initial temperature on the jet structure is less significant compared to the effect of initial pressure. The primary objective of the experiment was to collect near-field leakage data and analyze the characteristics of near-field leakage. It is hoped that this work will contribute to the improvement of research models that assess the consequences of potential high-pressure pipeline rupture scenarios.

The implementation of Carbon Capture and Storage-CCS has been projected to deliver substantial reductions to achieve the Net Zero scenario by 2050 and it is regarded a solution particularly relevant in decarbonizing heavy industries like cement production. However, historical challenges, partly caused by the absence of a viable business case, have hindered widespread adoption. Addressing the uncertainties surrounding the business case is crucial to identifying mechanisms that can expedite CCS deployment in these sectors. This study presents an analysis of a conceptual business case of a hypothetical CCS project at an operational cement plant in Europe, highlighting the impact of various uncertainties on its viability. It provides insights into potential project profitability under the influence of CO₂ prices and two types of subsidy schemes to achieve breakeven conditions based on the chosen assumptions. The findings indicate that anticipated CO₂ prices alone do not expedite the deployment of CCS, necessitating additional economic incentives or revenue streams to establish a financially viable business case. This could potentially be realized by transforming the business model of cement companies, including the creation of a market for CO₂-neutral cement and advocating for green public procurement in construction projects.

To optimize programmes of carbon capture and storage, it is crucial to understand how subsurface heterogeneity may control CO₂ dispersal in sedimentary reservoir successions. It is therefore necessary to evaluate the impact of subsurface modelling techniques on predictions in lithological and petrophysical heterogeneity, and on resulting dynamic behaviours. In this study, alternative idealized, unconditional static models were created that incorporate different types of sedimentary heterogeneities typical of fluvial meander-belt sedimentary successions, at different scales. These static models were produced using two different geostatistical algorithms based on multipoint statistics: SNESIM and DEESSE. Two alternative sets of geocellular grids were created that capture (i) macroscale levels of heterogeneity only (architectural elements) and (ii) both macro- and mesoscale (point-bar lithologies) heterogeneities, respectively. The geocellular models were populated with petrophysical data from a selected geological analogue (Barracouta Formation, Australia), imposing a depth-related trend based on the analysis of literature data. Porosity and permeability models were obtained via Gaussian random function simulations. These static models were used to simulate subsurface CO₂ injection over a 30-year period to enable tracking of plume propagation and a comparison between models incorporating different levels of facies heterogeneity. The study highlights the influence of the underlying facies framework on CO₂ dynamic simulations, since aspects of reservoir pressure redistribution and caprock pressure relief only emerge from models incorporating mesoscale features. Furthermore, predicted CO₂ plume displacement, injection rates and cumulative injected volumes are also affected by the facies-modelling approach. Modelling categories and strategies must be carefully selected in subsurface modelling workflows applied to plan CCS projects.

Geological carbon sequestration (GCS) is a method to reduce the emissions of CO₂ into the atmosphere. During GCS operations CO₂ is captured from the atmosphere or industrial activities and stored in geological formations for permanent storage. Monitoring is an important element of GCS because it ensures that the stored CO₂ remains safely contained in the intended formation during the long term. Additionally, monitoring wells can help to detect CO₂ leaks, prompt remediation actions, and provide valuable information to optimize storage by monitoring the behavior of the CO₂ over time. In this work, we propose a method for GCS anomaly detection based on an LSTM Autoencoder Neural Network and Isolation Forest. The LSTM-Autoencoder uses the monitor Bottomhole Pressure (BHP) response while CO₂ is being injected into a geological structure. To account for the subsurface uncertainty, multiple subsurface model realizations are created, and using reservoir simulation, the multiple monitor BHP are generated to capture the subsurface uncertainty. Anomaly BHP points are detected using the residuals of the LSTM-Autoencoder and Isolation Forest. Additionally, an anomaly score based on the subsurface uncertainty is proposed. Finally, the method robustness is evaluated using point outliers, level shift outliers, and transient shift outliers as anomaly BHP signals. Early detection of abnormal BHP pressure signals can indicate the presence of subsurface fractures, faults, or leaks. Consequently, the correct detection of anomaly points in the pressure signals is of great importance.

This study presents a geomechanical assessment of the 4km thick Paleocene-Pleistocene succession of the Tui field area from Taranaki Basin, offshore New Zealand. Based on the core measurements, suitable rock-mechanical models have been presented for static and dynamic elastic properties and rock strength. The Cenozoic stratigraphy is inferred to be normally compacted and devoid of any notable overpressure. Based on the C-quality stress indicators, we infer a 16.48 MPa/km minimum horizontal stress gradient, while the static elastic property-based model suggests a maximum horizontal stress gradient of around 21.15 MPa/km. The estimated in-situ stress magnitudes of the Paleocene-Miocene interval indicate a normal to strike-slip transitional stress regime (SHMax ∼Sv> Shmin). The petrographic and routine core analysis reported medium to coarse-grained, macro-megaporous sub-arkose arenites within the Paleocene Farewell sandstone and Eocene Kaimiro sandstone, which were considered as suitable candidates for geological storage. We analysed the injection stress paths for these two storage units as a result of pore pressure build-up and consequent stress perturbations. The maximum sustainable injection threshold is determined to ensure storage integrity. The conventional approach exhibits a 5-6 MPa repressurization window, while a much higher build-up threshold has been inferred from the model by utilizing pore pressure-stress coupling effects.

There is broad consensus on the key role that carbon dioxide (CO₂) capture, transport, and storage (CCTS) systems will play in mitigating climate change, either by removing CO₂ from the atmosphere and storing it permanently or by avoiding CO₂ emissions generated by point sources, especially from hard-to-abate sectors (e.g., waste-to-energy, cement, shipping or aviation). Although CCTS is ready to be implemented from a technical standpoint, the legal and regulatory framework required for its implementation and regulation could be further improved. In this article, we summarize and critically discuss the provisions of the Convention for the Protection of the Marine Environment of the North-East Atlantic (the ‘OSPAR Convention’), and of the London protocol, as well as of the European CCS and ETS Directives. With a focus on the European Economic Area, we highlight existing gaps and hurdles that should be tackled in view of the large-scale deployment of CCTS. Furthermore, as the legal landscape for CO₂ transport and geological storage is evolving rapidly, we provide an overview of recent clarifications on aspects of the existing legislation and a summary of new proposals presented by the European Commission in this space.

Accurate flow measurement plays a pivotal role in monitoring CO₂ flows across the CCS value chain. This not only bolsters the overall business model of the CCS industry, but also ensures adherence to environmental legislations and regulatory requirements. Unlike other industrial process fluids, such as water, oil & natural gas, it is unclear whether current commercially available metering technologies can meet the requisite accuracy levels, specifically the ±2.5 % recommended within the EU/UK European Trading Scheme for CO₂ mass transfer. Accordingly, the aim of this work was to gain a comprehensive understanding of CO₂ flow measurement within the context of CCS transport conditions. Firstly, GERG-2008 equation of state was implemented on REFPROP v10 to predict the optimal transport conditions for CO₂-rich mixtures and to understand the influence of non-condensable gas impurities in CCS flow operations. Then, a dedicated laboratory-scale gravimetric flow facility was designed and used to evaluate the performance of a Coriolis flow meter under gas, liquid, and supercritical flow conditions. The results indicate that the impurities have a relatively minor impact on the measurement performance of the meter, with maximum mean absolute measurement errors of 0.25 %, 0.12 %, and 0.28 % observed in gas, liquid, and supercritical CO₂ flow conditions, respectively. The findings support the use of Coriolis metering technology as a reliable option for CCS metering, underscoring its suitability for accurate measurements in single-phase CO₂ transport applications.

Time-lapse elastic full waveform inversion is used to monitor the spatio-temporal evolution of the CO${}_2$ plume during and after supercritical CO${}_2$ injection based on a series of time-lapse (repeated) cross-well seismic monitoring datasets obtained at the Nagaoka Carbon Capture and Storage (CCS) site in Japan. The full waveform inversion method successfully estimates the time-lapse velocity decrease of up to 30% within a thin 12 m layer, which is consistent with the magnitude and thickness of the well-log measurements. After the second monitoring survey, the velocity decrease becomes stable and gradually extends down dip along pre-existing geological structures. The full waveform inversion results starkly contrast with the previous estimates based on traveltime tomography. The previous traveltime tomography applications only used the traveltime-delays and resulted in low resolution with few percentage change which was not adequate to correctly resolve CO${}_2$ injection changes. The datasets pose significant challenges due to background noise, tube waves, apparent non-isotropic source radiation patterns, apparent reservoir velocity anisotropy and missing key acquisition parameters such as the number of stacks per shot point. To overcome these obstacles, we meticulously perform careful data preprocessing integrating both the body waves and tube waves. We develop waveform-based source mechanism estimation to represent non-isotropic source excitation, and then conduct forward modeling studies to constrain the anisotropy model.