scholarly journals Sensitivity Analysis Strategy to Assess the Salting-Out Problem during CO2 Geological Storage Process

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jie Ren ◽  
Di Feng
Keyword(s):  
Sensitivity Analysis ◽  
Sensitivity Coefficient ◽  
The Other ◽  
Saline Aquifers ◽  
Geological Storage ◽  
Residual Saturation ◽  
Salting Out ◽  
Global Sensitivity ◽  
Deep Saline Aquifers ◽  
Selection Of

The sensitivity analysis of the salting-out effect on well injectivity is a significant work in the research of geological storage of CO2 in deep saline aquifers, which is helpful in the selection of storage sites and the design of the injection strategy. We conduct a detailed sensitivity analysis about the salting-out process using the local sensitivity method and two global sensitivity methods. Sensitivity coefficients showed that brine salinity (XNaCl) has the highest sensitivity and interaction effect, the CO2 injection rate (QCO2) has a greater influence in the early stage of the salting-out process and a smaller influence in the end stage, and the other three parameters (empirical parameters related to the pore distribution m, the liquid residual saturation in the relative permeability function Splr, and the liquid residual saturation in the capillary pressure function Sclr) have a smaller sensitivity. This paper also analyzes the calculation amount of different sensitivity methods and suitable ways of obtaining the sensitivity coefficient and reveals the following. (1) The sensitivity coefficient changes dynamically with time, if only the sensitivity of the final state is taken into account on a long-time physical process, and some sensitive parameters during the process may be neglected. (2) The selection of the sample size should be based on the convergence of multiple calculations, and the results of the empirical calculation are uncertain. (3) The calculation of Sobol sensitivity is complicated, the results calculated by surrogate model depend on whether the sample is representative enough; on the other hand, it is feasible to use Sti-Si approximation to characterize the second-order sensitivity to reduce the computation. The research results not only reveal the sensitivity of the parameters related to the injection well salting-out problem during CO2 storage in deep saline aquifers but also guide the calculation of global sensitivity analysis with a similar physical process.

scholarly journals Global Sensitivity Analysis to Assess Salt Precipitation for CO2 Geological Storage in Deep Saline Aquifers

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Yuan Wang ◽  
Jie Ren ◽  
Shaobin Hu ◽  
Di Feng
Keyword(s):  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Injection Rate ◽  
Injection Well ◽  
Saline Aquifers ◽  
Salt Precipitation ◽  
Empirical Parameter ◽  
Global Sensitivity ◽  
Morris Method ◽  
Input Variables

Salt precipitation is generated near the injection well when dry supercritical carbon dioxide (scCO2) is injected into saline aquifers, and it can seriously impair the CO2 injectivity of the well. We used solid saturation (Ss) to map CO2 injectivity. Ss was used as the response variable for the sensitivity analysis, and the input variables included the CO2 injection rate (QCO2), salinity of the aquifer (XNaCl), empirical parameter m, air entry pressure (P0), maximum capillary pressure (Pmax), and liquid residual saturation (Splr and Sclr). Global sensitivity analysis methods, namely, the Morris method and Sobol method, were used. A significant increase in Ss was observed near the injection well, and the results of the two methods were similar: XNaCl had the greatest effect on Ss; the effect of P0 and Pmax on Ss was negligible. On the other hand, with these two methods, QCO2 had various effects on Ss: QCO2 had a large effect on Ss in the Morris method, but it had little effect on Ss in the Sobol method. We also found that a low QCO2 had a profound effect on Ss but that a high QCO2 had almost no effect on the Ss value.

scholarly journals Liquid CO2 injection for geological storage in deep saline aquifers

2013 ◽  
Vol 14 ◽  
pp. 84-96 ◽  
Author(s):  
Víctor Vilarrasa ◽  
Orlando Silva ◽  
Jesús Carrera ◽  
Sebastià Olivella
Keyword(s):  
Saline Aquifers ◽  
Co2 Injection ◽  
Geological Storage ◽  
Liquid Co2 ◽  
Deep Saline Aquifers

scholarly journals Modeling of Carbon Dioxide Leakage from Storage Aquifers

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 80 ◽  
Author(s):  
Parvaneh Heidari ◽  
Hassan Hassanzadeh
Keyword(s):  
Driving Forces ◽  
Mechanistic Model ◽  
Co2 Storage ◽  
Transport Processes ◽  
Saline Aquifers ◽  
Storage Site ◽  
Geological Storage ◽  
Co2 Leakage ◽  
Deep Saline Aquifers ◽  
The Impact

Long-term geological storage of CO2 in deep saline aquifers offers the possibility of sustaining access to fossil fuels while reducing emissions. However, prior to implementation, associated risks of CO2 leakage need to be carefully addressed to ensure safety of storage. CO2 storage takes place by several trapping mechanisms that are active on different time scales. The injected CO2 may be trapped under an impermeable rock due to structural trapping. Over time, the contribution of capillary, solubility, and mineral trapping mechanisms come into play. Leaky faults and fractures provide pathways for CO2 to migrate upward toward shallower depths and reduce the effectiveness of storage. Therefore, understanding the transport processes and the impact of various forces such as viscous, capillary and gravity is necessary. In this study, a mechanistic model is developed to investigate the influence of the driving forces on CO2 migration through a water saturated leakage pathway. The developed numerical model is used to determine leakage characteristics for different rock formations from a potential CO2 storage site in central Alberta, Canada. The model allows for preliminary analysis of CO2 leakage and finds applications in screening and site selection for geological storage of CO2 in deep saline aquifers.

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