| 1. |
- Joodaki, Saba, et al.
(författare)
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Model analysis of CO2 residual trapping from single-well push pull test based on hydraulic withdrawal tests : Heletz, residual trapping experiment I
- 2020
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Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836 .- 1878-0148. ; 97
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Tidskriftsartikel (refereegranskat)abstract
- Residual or capillary trapping is one of the key trapping mechanisms for geological storage of CO2. Yet, very few studies so far have attempted to estimate the residual trapping and the related characteristic parameter, residual saturation, in situ. At Heletz, a pilot CO2 injection site in Israel a single-well push-pull experiment to estimate residual gas saturation in situ was carried out during autumn 2016. The main characterization method was hydraulic withdrawal tests. The residually trapped zone was also created by means of fluid withdrawal, by first injecting CO2 and then withdrawing fluids leaving behind the immobile residual CO2. This paper presents the first model interpretation of the experimental results. Numerical modeling with TOUGH2/ECO2N was carried out to model the entire test sequence, the focus being in matching the collected pressure, temperature and flow data as well as observations of gas content in the borehole. The experimental results could be well fitted with the model that also is in agreement with previously collected petro-physical data. The results indicate a somewhat lower residual gas saturation than that measured in the laboratory, the estimated maximum residual saturation from the field experiment being 10% and the corresponding value from the core 20%. The results also indicate that most of the CO2 entered the upper reservoir layer, thus actually giving an estimate of the effective residual trapping in that layer. Overall, pressure response gave a clear signal and was an effective method in getting an estimate of the effective residual trapping in the interval tested.
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| 2. |
- Joodaki, Saba, et al.
(författare)
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Model analysis of CO2 residual trapping from single-well push pull test - Heletz, Residual Trapping Experiment II
- 2020
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Ingår i: International Journal of Greenhouse Gas Control. - : ELSEVIER SCI LTD. - 1750-5836 .- 1878-0148. ; 101
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Tidskriftsartikel (refereegranskat)abstract
- Residual or capillary trapping is one of the key trapping mechanisms for CO2 geological storage. At the Heletz, Israel, pilot injection site, two dedicated field experiments have been carried out to characterize it in-situ. This paper presents the model analyses of the second of these tests, the Residual Trapping Experiment II (RTE II). In the experiment hydraulic, tracer and thermal tests before and after the generation of the residually trapped zone are used to quantify residual saturation. The creation of the residually trapped zone is based on injection of CO2-saturated-water following injection of free-phase supercritical CO2. For the modeling, both a radial-symmetric model with homogeneous layer properties and 3D model with stochastically heterogeneous properties were used. Extensive parameter sensitivity studies were carried out and various well-geometry related fluid injection/withdrawal scenarios were considered. In terms of the best estimate for the maximum residual saturation, this experiment, like the previous RTE I experiment, gave the best agreement with a residual gas saturation of 0.1, this value being somewhat lower than the core-measured value of 0.2. Overall, the pressure response provided a very robust signal enabling to distinguish different values of residual saturation as well as the extent of sections where gas blocking for water flow could have occurred. Analysis of the tracer data indicated the presence of phenomena such as gas-blocking water flow, the importance of multi-layer and channelized flow and transport, and the importance of taking into account the processes in the actual injection/production well also.
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| 3. |
- Joodaki, Saba
(författare)
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Residual Trapping in Geological Storage of CO2 : Determination from Field Experiments and Data Analysis Using Numerical Modeling
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Geological storage of CO2 in deep saline aquifers is one of the methods to mitigate the release of this greenhouse gas into the atmosphere. The efficiency of this solution can be improved by better understanding of the relevant trapping processes, as well as by improving available injection techniques and developing tools for more accurate site characterization. This Thesis has implemented numerical simulations to investigate the processes that affect the capillary trapping of the injected CO2 in a saline aquifer with the focus on two field experiments carried out in Heletz, Israel. The two experiments, applying different test sequences and characterization techniques, were carried out with the focus on determining the parameter of the maximum residual gas saturation. The collected data and a detailed description of the injection site and operational procedures are presented in Paper I. In Paper II, numerical modeling is used to interpret the pressure and temperature data recorded during the first residual trapping experiment (RTE I). The second residual trapping experiment (RTE II) and the corresponding numerical modelling for interpretation of hydraulic and partitioning tracer tests is presented in Paper III. Overall, the data analysis and the results from numerical simulations for both experiments were in agreement and suggested that push-pull hydraulic test is a robust technique that can provide useful information to estimate the parameter of residual gas saturation in situ with reasonable costs. Both thermal and tracer tests can provide valuable data to further characterize the formation however the operational difficulties can be limiting factors. In Paper IV, the effect of different parameters to increase the efficiency of the Water alternating Gas (WAG) technique are investigated. For this study numerical simulation was used to model a heterogeneous formation based on parameters obtained from the Heletz site. For the formation used in this study, it was shown that higher water injection rate has a stronger effect on dissolution trapping than CO2 injection rate. The most important design parameter was, however, the WAG ratio. It was also concluded that the design parameters of WAG technique are site-specific and application of this method requires extensive site characterization.
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| 4. |
- Joodaki, Saba, et al.
(författare)
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Simulation of CO2 injection into a Baltic Sea saline aquifer and seismic monitoring of the plume
- 2013
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; , s. 355-364
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Tidskriftsartikel (refereegranskat)abstract
- TOUGH2/ECO2N was used to simulate CO2 injection into a saline aquifer in the Baltic Sea and the effect of different amounts of CO2 injection on the seismic response. The Biot-Gassmann model was used to convert the simulated saturation and densities to seismic velocities and synthetic seismic responses before and after injection were compared. The results show that the amplitude changes in the seismic response are detectable even for small amounts of injected CO2, while noticeable signs of velocity pushdown, as a signature of the CO2 substitution, could only be observed if the injection rate is high enough.
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| 5. |
- Joodaki, Saba, et al.
(författare)
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The effect of designing parameter of WAG injection on enhancement of CO2trapping in heterogeneous formations: A numerical study
- 2017
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Ingår i: Greenhouse Gases. - : Wiley. - 2152-3878. ; 7:6, s. 1008-1019
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Tidskriftsartikel (refereegranskat)abstract
- Dissolution and residual trapping of CO2 injected in saline aquifers can be influenced by injection strategies applied. In this study, we focus on the water-alternating-gas (WAG) strategy and investigate the importance of parameters needed to design an effective WAG injection sequence, including (i) CO2 and water injection rates, (ii) WAG ratio, and (iii) number of cycles. Using TOUGH2-ECO2N, we perform 3D numerical simulations of sequences of CO2 and water injection into a heterogeneous formation. Hysteresis in relative permeability and capillary pressure functions is considered based on the Land trapping model. Results show that to design a WAG injection in a high permeable formation, the WAG ratio and number of injection cycles are more important parameters than the CO2 and water injection rates. Increasing the total amount of water injection (i.e., decreasing the WAG ratio for given total amount of injected CO2) improves the CO2 dissolution and residual trapping. It is also shown that increasing the number of injection cycles has a negative effect on both residual and dissolution trapping as measured at the end of the injection sequence, because both the free-phase and the dissolved CO2 plumes in the one-cycle injection scenario reach farther distances and occupy larger reservoir volumes than in the multi-cycle injection. This result means that while water injection following the CO2 injection improves trapping in comparison with the CO2-only injection strategy, the WAG scheme with multiple cycles should not be chosen to enhance trapping for the scenario considered in this study.
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| 6. |
- Moghadasi, Ramin, et al.
(författare)
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A Stochastic Model for Interpreting the Partitioning Tracer Recovery from Residual Trapping Experiment at Heletz, Israel, Pilot Injection Site
- 2019
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Konferensbidrag (refereegranskat)abstract
- Residual trapping is one of the key trapping mechanisms for geological storage of CO2. While relatively abundant experimental data exists on laboratory cores, only very few experiments have attempted to address this parameter in the field. As part of the experimental program at Heletz, Israel, pilot CO2 injection site (Niemi et al. 2012, 2016), two small-scale push-pull CO2 injection experiments were carried out to determine residual trapping in-situ (Niemi et al. 2012). In the second one of these experiments, carried out in 2017, the main method for characterizing the residual trapping was injection of partitioning tracer Krypton before and after creating the residually trapped zone. This paper presents one of the model interpretations of the tracer experiment, by assuming a stochastically heterogeneous interpretation of the properties of the storage reservoir. Based on field data on layer properties, heterogeneous models are generated using geostatistical library GSLIB (Finsterle and Kowalsky 2007) and multiple realization Monte Carlo simulations of the experiment test sequence are carried out using the simulator iTOUGH with the equation of state modules EOS7C/ECO2N (Pruess 2005: Oldenburg et al. 2004). Effect of heterogeneity characteristics on simulated tracer recovery is analyzed and compared to that from the field data. The results provide us a better understanding on how heterogeneity effects can influence partitioning tracer behavior and its partitioning into trapped CO2.
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| 7. |
- Niemi, Auli, et al.
(författare)
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Characterizing CO2 residual trapping in-situ by means of single-well push-pull experiments at Heletz, Israel, pilot injection site : experimental procedures and results of the experiments
- 2020
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Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836 .- 1878-0148. ; 101
-
Tidskriftsartikel (refereegranskat)abstract
- Two dedicated field experiments have been carried out at the Heletz, Israel pilot CO2 injection site. The objective has been to quantify the CO2 residual trapping in-situ, based on two distinctly different methods. Both experiments are based on the principle of a combination of hydraulic, thermal and/or tracer tests before and after creating the residually trapped zone of CO2 and using the difference in the responses of these tests to estimate the in-situ residual trapping. In Residual Trapping Experiment I (RTE I), carried out in autumn 2016, the main characterization test before and after the creation of the residually trapped zone were hydraulic withdrawal tests. In this experiment, the residually trapped zone was also created by fluid withdrawal, by first injecting CO2, then withdrawing fluids until CO2 was at residual saturation. The second experiment, Residual Trapping Experiment II (RTE II), was carried out autumn 2017. In this experiment, the residually trapped CO2 zone was created by CO2 injection, followed by the injection of CO2-saturated water, to push away the mobile CO2 and leave the residually trapped CO2 behind. In this test, the main reference test carried out before and after creating the residually trapped zone was injection and recovery of gas partitioning tracer Krypton. This paper presents the experimental procedures and results of these experiments. A hydraulic withdrawal test as a characterization method was robust and gave a clear signal. Given the difficulties in injecting water optimally saturated with CO2, in order not to dissolve the residually trapped CO2 or to create situations with excess mobile gas, withdrawal test may also be a generally preferable hydraulic testing method, in comparison to injection. The limitation of any hydraulic test is that it only gives an averaged value over the test section. At Heletz additional information about CO2 distribution was obtained based on thermal measurements and by monitoring the pressure difference between the two sensors in the bolehole. The latter could be used to estimate the amount of mobile CO2 in the well test section. Tracer experiments with gas partitioning tracers can in principle give more detailed information of CO2 residual distribution in the reservoir than hydraulic tests can, but are also far more complicated to carry out, involving sophisticated and sensitive equipment. In the Heletz case the optimal injection of CO2-saturated water turned out to be difficult to achieve. Creating the zone of residual saturation by means of fluid withdrawal rather than by injecting CO2-saturated water seemed a more robust approach. Monitoring the gas contents in the test interval gave good guidance on the state of the system. Model interpretations of the two experiments to obtain values for CO2 residual saturation are presented in companion papers in this same Special Edition.
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| 8. |
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| 9. |
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| 10. |
- Tian, Liang, et al.
(författare)
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Integrated simulations of CO2 spreading and pressure response in the multilayer saline aquifer of South Scania Site, Sweden
- 2016
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Ingår i: Greenhouse Gases. - : Wiley. - 2152-3878. ; 6:4, s. 531-545
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Tidskriftsartikel (refereegranskat)abstract
- An integrated modeling approach/workflow, in which a series of mathematical models of different levels of complexity are applied to evaluate the geological storage capacity of the Scania Site, southwest Sweden, is presented. The storage formation at the site is a layered formation limited by bounding fault zones, and injection is assumed to take place from one existing deep borehole into all layers. A semi-analytical model for two-phase flow is first used to evaluate the pressure response and related parameter sensitivity, as well as the first estimates of acceptable injection rates. These results are then used to guide the more detailed numerical simulations that address both pressure response and plume migration. The vertical equilibrium (VE) model is used to obtain a preliminary understanding of the plume migration with a larger number of simulations. Finally the full TOUGH2/ECO2N simulations are performed for the most detailed analyses of pressure responses and plume migration. Throughout, the results of the different modeling approaches are compared against each other. It is concluded that the key limiting factor for the storage capacity at the site in the injection scenario considered is the fast CO2 migration within the high permeability layer. Future studies can address alternative injection scenarios, including horizontal injection wells and injection to other layers than the high permeability layer.
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