A comprehensive review of remediation strategies for mitigating salt precipitation and enhancing CO2 injectivity during CO2 injection into saline aquifers.

Geological CO2 sequestration is a proven method for mitigating climate change by reducing atmospheric CO2 levels. However, CO2 injection often induces salt precipitation, leading to decreased formation permeability, which in turn limits CO2 injectivity and storage capacity. Conventional approaches, such as freshwater and low-salinity water injection, have been employed to mitigate salt precipitation. Despite their widespread use, these methods provide only temporary improvement and can be ineffective in some scenarios, resulting in long-term issues such as salt recrystallization and clay swelling. Given the complexity and significance of this issue, a comprehensive review of salt precipitation mechanisms and remediation techniques is essential. This paper critically examines the processes of salt precipitation during CO2 injection in saline aquifers and evaluates various remediation techniques aimed at improving CO2 injectivity. The paper reviews the influence of CO2 flow dynamics, geochemical reactions, and fluid properties on salt precipitation and pore throat accumulation, assessing the efficacy and limitations of existing mitigation methods. Additionally, the paper explores alternative techniques with potential for long-term CO2 sequestration, analyzing their advantages and drawbacks. Based on insights from the reviewed sources, the paper recommends exploring alternative treatment measures and the integration of hybrid solutions to enhance CO2 injectivity. The findings presented serve as a valuable reference for advancing research and practice in this critical area, offering a deeper understanding of the challenges and potential solutions for effective CO2 sequestration in saline aquifers.

Experimental study of asphaltene deposition during CO2 and flue gas injection EOR methods employing a long core.

Gas injection is a well-known method for enhancing oil recovery (EOR). The utilization of greenhouse gases, such as carbon dioxide (CO2) or flue gas, offers the dual advantage of reducing greenhouse gas emissions while potentially enhancing the sweep efficiency in oil recovery. Nevertheless, one of the notable challenges encountered when using these gases is the precipitation and deposition of asphaltenes, leading to formation damage and a decrease in reservoir permeability, particularly in the case of light oil reservoirs. In this study, CO2 and flue gas were injected into an elongated core sample comprising four individual core plugs under reservoir conditions to displace the light live oil. The recovery factor and asphaltene deposition along the core holder were assessed and compared as two crucial parameters within the gas injection scenario. Our results indicate a significantly higher recovery factor of 86% achieved with CO2 injection compared to 36% with flue gas injection, attributable to differences in their interfacial tension and miscibility. However, the CO2 injection method exhibits more pronounced formation damage. Individual assessment of each core plug reveals that permeability impairment is most acute in the initial two core plugs, situated closer to the injection face of the extended core. These findings enhance our understanding of the mechanisms contributing to permeability impairment resulting from asphaltene deposition during CO2 and flue gas injection for EOR.

Lesson learned from the assessment of planned converted CO2 injection well integrity in Indonesia - CCUS project.

The risk of CO2 leakage from carbon capture, utilization, and storage (CCUS) wells and geological storage sites must be properly assessed before the implementation of CO2 injection. According to ISO 27914 and ISO/FDIS 27916, the design and construction of an injection well needs to guarantee safety and ability to contain the stored CO2 over a long-term period. However, these standards alone were inadequate to evaluate the well integrity due to the need to specify criteria, duration of measurement, and range of measurement parameters of the available tools according to industries' best practices. The methodology used in the study adapted applicable and readily-available international standards, field experiences, and lessons learned that could be used to support the construction of new and/or the conversion of existing oil and gas wells into CO2 injection wells. This study focused on Jepon-1 in Gundih field, Indonesia, an abandoned oil and gas well. Its actual conditions, well integrity, capabilities of the equipment used in the workover and logging operations, and its limitations in checking the conditions of various crucial aspects of integrity, were evaluated. The results showed that the application of the international standards could not fulfill all the detailed requirements of integrity evaluation of the JPN-1 well due to its particular condition and situation. Other field experiences needed to be adapted, improved, and incorporated in the integrity evaluation of this well. Additionally, longer duration of measurement and more accurate and sensitive logging evaluation tools, combined with temperature logging tools, are required to detect leakage that could not be identified by the commercial tools used in this well. The result of this well integrity study will be used as a fundamental basis for constructing CCUS well regulations by the Government and stakeholders.

Comparison of Two Diagnostic Techniques for the Apis mellifera Varroatosis: Strengths, Weaknesses and Impact on the Honeybee Health.

Varroa destructor is the most dangerous pest that poses a threat to honey bee survival. In recent years, increasingly worrying phenomena of drug resistance have occurred to various active ingredients of pharmaceutical formulations used to control this parasitosis. Determining the level of infestation is essential to preventing the inappropriate use and abuse of veterinary medicines, and to choose the most appropriate time for treatment. This comparative study investigates the sensitivity and diagnostic accuracy of two field techniques for diagnosing V. destructor infestations in hives. The EasyCheck device (Véto-pharma) was used in two of its application modes, namely, the sugar roll test and carbon dioxide (CO2) injection. The experiments were conducted on 15 samples of 300 bees each taken from the same frame and checked for the presence of mites using standard and modified field techniques in both uncaged and caged queen hive conditions. The results demonstrate that the sugar roll technique is significantly more effective and safer than CO2 injection, allowing for a higher accuracy in diagnosing a V. destructor infestation. Furthermore, the evaluation of mites present on bees in brood block conditions has proven to be particularly reliable. Considering the number of mites on the filter of the device as an additional step helps to implement the diagnostic accuracy of the CO2 injection technique, however, not achieving the efficacy results of the sugar roll.

Calcium-Reduced Micellar Casein Concentrate-Physicochemical Properties of Powders and Functional Properties of the Dispersions.

This study aimed to examine the physicochemical properties of 30% calcium (Ca)-reduced micellar casein 80% protein powders (RC-MCC) and the functional properties of the resultant dispersions. The calcium reduction in the micellar casein (MCC) powder was achieved by subjecting the liquid micellular casein obtained from the microfiltration of pasteurized skim milk to carbon dioxide (CO2) treatment before and during ultrafiltration. The CO2 injection was controlled to obtain a 0 and 30% reduction in calcium in the C-MCC (control) and RC-MCC powders, respectively. The MCC powders were tested for physicochemical properties such as chemical composition, particle size distribution, and bulk density. The MCC powders were reconstituted in deionized water to test the functional properties of the dispersions, i.e., solubility, viscosity, heat stability, emulsifying capacity, emulsion stability, foam capacity, and foam stability. The CO2 injection did not result in any significant differences in the composition except mineral contents, particularly calcium. The particle size and bulk density of RC-MCC powders were significantly (p < 0.05) lower than control powders. The RC-MCC powder dispersions showed increased heat stability compared to control, whereas no significant changes in viscosity and emulsification capacity were observed between the two dispersions. However, the emulsion stability and foam stability of RC-MCC dispersions were significantly lower than C-MCC dispersions. This study showed that by utilizing a novel microfiltration−CO2 injection−ultrafiltration process, 30% calcium-reduced MCC powder was commercially feasible. This research also provides a detailed understanding of the effect of calcium reduction on the functional properties of resultant MCC dispersions. It showed that calcium reduction could improve the solubility of the powders and heat stability and foam capacity of the dispersions.

An overview on the enhanced gas condensate recovery with novel and green methods.

A consideration of the negative environmental aspects of fossil fuels has made natural gas the best choice to meet the human demand for energy. The condensate gas reservoir is one source of gases that tolerates skin problems (liquid blockage). Conventional methods for inhibiting or removing liquid blockages are momentary treatments, non-eco-friendly, and expensive. Therefore, new methods have been introduced, such as wettability alteration toward liquid repellency, renewable energies, thermochemical reactions and waves for heating reservoirs, and CO2 injection. This paper reviews the methods for altering the wettability of porous media by fluorochemicals, fluorinated nanoparticles (NPs), and free fluorocarbon materials from natural substances. NPs, particularly silicon-based types, as a green, clean, and emerging technology that are more compatible with the environment, were investigated for their ability to alter the wettability and upgrade conventional materials, such as polymers and surfactants. The feasibility of using renewable energies, thermochemical reactions, and waves for heating the gas condensate reservoir to overcome the skin problem and return the reservoir to the reasonable and economical gas production is reviewed. Finally, CO2 injection is introduced as a multi-purpose green method to enhance gas condensate recovery and allow CO2 sequestration.

Impacts of injection temperature on the CO2 injection capacity in the different sloping formations.

The CO2 injection capacity directly affects the CO2 storage efficiency. Injection temperature and formation sloping degree affect the CO2 injection capacity. Based on the actual geological conditions of the Shiqianfeng Formation in the Ordos Basin of China, a three-dimensional (3D) simulation model was established to evaluate pressure, temperature, CO2 spatial distribution, and injection amount. A total of 17 simulation schemes were carried out using the TOUGH2-ECO2N fluid property module. The results showed that the injection temperature had a significant impact on the CO2 injection capacity in the different sloping degree formations. Increasing the injection temperature resulted in increased formation pressure, CO2 gas phase, dissolved phase, and total injection amount, while decreasing the CO2 concentration, and the formation pressure changed obviously with the formation sloping degree. The larger the formation sloping degree was, the less the CO2 injection amount. Higher injection temperature and smaller sloping degree formation were more favorable for CO2 injection, and the CO2 injection capacity was stronger, signaling that it should be selected to store CO2 in the future.

Flow Cytometry Assessment of Microalgae Physiological Alterations under CO2 Injection.

Growth rate (GR), esterase activity (EA), membrane potential (MP), and DNA content were measured by flow cytometry to test if this powerful tool could be included in risk assessment and monitoring programs. This study tests a battery of endpoints that were measured on Scenedesmus (Acutodesmus) obliquus as model species, under high levels of injected CO2 to be proposed as biomarkers of effect. New technologies such as carbon capture and storage (CCS) bring positive consequences on CO2 mitigation strategies but also could have negative consequences if a CO2 leakage occurs during injection. Under this scenario, pH might drop down to 4 pH units around the pipe where the leakage happens. The study focus on to ascertain if the endpoints fulfill the requirements such as sensitiveness, be timely and cost-effective, be easy to measure and interpret, and be nondestructive, valuable attributes in effective biomarkers. CO2 injected at high levels significantly affects the EA, the membrane polarization, as well as GRs. However the DNA content did not shown a clear response under this condition. In conclusion, the GR, the EA, and the MP analyzed by flow cytometry fulfilled the attributes mentioned above and are proposed as biomarkers of effect in CCS monitoring programs. © 2020 International Society for Advancement of Cytometry.

Hybrid connectionist model determines CO2-oil swelling factor.

In-depth understanding of interactions between crude oil and CO2 provides insight into the CO2-based enhanced oil recovery (EOR) process design and simulation. When CO2 contacts crude oil, the dissolution process takes place. This phenomenon results in the oil swelling, which depends on the temperature, pressure, and composition of the oil. The residual oil saturation in a CO2-based EOR process is inversely proportional to the oil swelling factor. Hence, it is important to estimate this influential parameter with high precision. The current study suggests the predictive model based on the least-squares support vector machine (LS-SVM) to calculate the CO2-oil swelling factor. A genetic algorithm is used to optimize hyperparameters (γ and σ 2) of the LS-SVM model. This model showed a high coefficient of determination (R 2 = 0.9953) and a low value for the mean-squared error (MSE = 0.0003) based on the available experimental data while estimating the CO2-oil swelling factor. It was found that LS-SVM is a straightforward and accurate method to determine the CO2-oil swelling factor with negligible uncertainty. This method can be incorporated in commercial reservoir simulators to include the effect of the CO2-oil swelling factor when adequate experimental data are not available.

Effects of extrusion with CO2 injection on physical and antioxidant properties of cornmeal-based extrudates with carrot powder.

Carrot powder and cornmeal were extruded at ratios of 0:100, 10:90, and 20:80 with and without CO2 injection at die temperatures of 80, 100, and 120 °C. The effects of the composition of the extrudate, die temperature, and CO2 injection on physicochemical and antioxidant properties of extruded products were studied. The results showed that die temperature had a significant effect on expansion ratio (ER), specific length, piece density, color, water absorption index (WAI), and water solubility index (WSI) (p < 0.05). The injection of CO2 significantly affected the ER, WAI, WSI, lightness, redness, microstructure, total phenolic content, and the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity of extrudates (p < 0.05). Increasing the proportion of carrot powder in extrudates resulted in better antioxidant properties and higher levels of crude ash, crude fat, crude protein, and redness; however, it resulted in lower WAI, lightness, and yellowness (p < 0.05). The study demonstrated that extrusion with CO2 injection and addition of carrot powder may improve the nutritional quality and structure-forming ability of extrudates.

The Effects of CO2 Injection and Barrel Temperatures on the Physiochemical and Antioxidant Properties of Extruded Cereals.

The effects of CO2 injection and barrel temperatures on the physiochemical and antioxidant properties of extruded cereals (sorghum, barley, oats, and millet) were studied. Extrusion was carried out using a twin-screw extruder at different barrel temperatures (80, 110, and 140°C), CO2 injection (0 and 500 mL/min), screw speed of 200 rpm, and moisture content of 25%. Extrusion significantly increased the total flavonoid content (TFC) of extruded oats, and ß-glucan and protein digestibility (PD) of extruded barley and oats. In contrast, there were significant reductions in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, PD of extruded sorghum and millet, as well as resistant starch (RS) of extruded sorghum and barley, and total phenolic content (TPC) of all extrudates, except extruded millet. At a barrel temperature of 140°C, TPC in extruded barley was significantly increased, and there was also an increase in DPPH and PD in extruded millet with or without CO2 injection. In contrast, at a barrel temperature of 140°C, the TPC of extruded sorghum decreased, TFC of extruded oats decreased, and at a barrel temperature of 110°C, PD of extruded sorghum without CO2 decreased. Some physical properties [expansion ratio (ER), specific length, piece density, color, and water absorption index] of the extrudates were significantly affected by the increase in barrel temperature. The CO2 injection significantly affected some physical properties (ER, specific length, piece density, water solubility index, and water absorption index), TPC, DPPH, ß-glucan, and PD. In conclusion, extruded barley and millet had higher potential for making value added cereal-based foods than the other cereals.

Application of CO2 injection method in the magnetic resonance imaging preoperative staging diagnosis for stage Ⅰ carcinoma of endometrium / 肿瘤研究与临床

Objective To explore the accuracy rate of CO2 injection method and conventional magnetic resonance imaging (MRI) in the staging diagnosis for stage Ⅰ carcinoma of endometrium.Methods Preoperative staging diagnosis for stage Ⅰ carcinoma of endometrium was done,and the method of injecting CO2 gas into the uterine lumen by catheter was applied for pelvic MRI scan in 38 cases of stage Ⅰ carcinoma of endometrium.The pathological staging result was treated as the gold standard to compare the accuracy rate of CO2 injection method with conventional scan method (43 cases).Results For conventional MRI scan group,the accuracy rate of staging diagnosis in stage Ⅰ carcinoma of endometrium was 81.3 ％ (35/43),including stage Ⅰ A 75.0 ％(6/8),stage Ⅰ B 83.9 ％(26/31),stage Ⅰ c 75.0 ％(3/4).For CO2 injection group,the accuracy rate was 89.4 ％(34/38),including stage Ⅰ A 85.7 ％(6/7),stage Ⅰ B 88.9 ％(16/18),stage Ⅰ c 84.6 ％ (12/13).There was a statistical difference between the accuracy rates of two methods (x2=7.81,P ＜ 0.05).Conclusion Compared with conventional scan method,the CO2 injection method with better simplicity,safety and application value,could be more accurate to determine the location of endometrial cancer and the degree of myometrial infiltration.

Effects of formulation, extrusion cooking conditions, and CO2 injection on the formation of acrylamide in corn extrudates.

BACKGROUND: Acrylamide is a possible carcinogen and known to form in heat-treated carbohydrate-rich foods. This study was designed to investigate the effects of different ingredients (reducing sugars, chemical leavening agents, citric acid), processing conditions (feed moisture content: 22, 24 or 26%, exit die temperature: 110, 150 °C), and extrusion cooking methods (with or without CO2 injection) on acrylamide formation. RESULTS: The type of reducing sugar did not have a considerable effect on acrylamide formation, while increased exit die temperature had a promoting effect. Addition of chemical leavening agents (sodium bicarbonate and ammonium bicarbonate) into formulations increased acrylamide formation levels. The addition of citric acid prevented acrylamide formation, but its effect on textural properties was detrimental. Acrylamide levels of extrudates decreased gradually with increasing feed moisture in all formulations. Acrylamide content of extrudates produced with 22% feed moisture decreased by 61% in the CO2 injection method compared to conventional extrusion. Furthermore, an 82% decrease in acrylamide content was observed with the combined effect of CO2 injection and increasing feed moisture content from 22 to 24% and decreased below the limit of quantification with a further increase in feed moisture. CONCLUSION: A substantial decrease in final acrylamide level is probably due to restriction of two major steps of acrylamide formation: dehydration and decarboxylation.

Influence of germination and extrusion with CO(2) injection on physicochemical properties of wheat extrudates.

Whole wheat and germinated wheat flour were extruded in a laboratory co-rotating twin screw extruder with die temperatures (90 and 130°C), screw speeds (150 and 200rpm) and CO2 injection. The effects of germination and extrusion process on specific mechanical energy (SME) input, expansion ratio, specific length, piece density, elastic modulus, breaking strength, colour, water solubility index (WSI), water absorption index (WAI) and microstructure were determined. The study showed that the use of germinated wheat flour increased the specific length, lightness and the WSI. When CO2 was injected, the expansion ratios (only 90°C die temperature for extruded germinated wheat) and lightness were significantly increased (p<0.05). The chemical properties (crude protein, fat, ash, reducing sugar, γ-aminobutyric acid, soluble arabinoxylans, ß-glucan and phytic acid) were also investigated. The germination step and extrusion process mainly affected the chemical properties. However, the difference of die temperatures, screw speed and CO2 injection had slight effect on the chemical properties.