Effects Of CO2 Injection Research Articles

ANALISIS PENGARUH INJEKSI CO2 TERHADAP RECOVERY FACTOR MENGGUNAKAN SIMULASI CMG DI LAPANGAN X

X-Field is located in South Sumatra, where there are several gas fields with considerable CO2 gas potential. In this field, no research has been conducted on CO2 injection neither in the laboratory nor simulation. Therefore, the purpose of this study is to analyze the effect of CO2 injection on the value of recovery factor with one-dimensional simulation using CMG. To be able to make an accurate simulation model, it is necessary to do validation by comparing the results obtained with the CO2 injection test from experiments in the laboratory. Laboratory experimental data used in this study is from Vulin’s literature. The result of recovery factor for X-field is 98.80%. From the results of this study, it is known that the injection rate of CO2 has no effect on changes in recovery factor. However, the difference of CO2 injection pressure in these two samples influences the change in recovery factor. The higher injection pressure of CO2 in an immiscible condition is, the higher the value of the recovery factor is achieved. In addition, the difference in oil composition in these two samples affects the value of MMP, where the higher the intermediate component of a reservoir fluid is, the lower the MMP will be. X-field has a high intermediate component fraction, therefore the value of MMP obtained is lower than the MMP from Vulin’s literature. The value of MMP in X-field is 2610.68 psia

The injection of CO2 to hypersaline geothermal brine: A case study for Tuzla region

Scaling is a serious issue for geothermal power plants since it remarkably decreases the harvesting of energy. The reduction of pH by organic acids whose structure is close to CO2 for instance formic acid has been an effective solution for the minimization of scaling. Herein, the effect of CO2 injection on the formation of scaling particularly metal-silicates was investigated for the model case of Tuzla Geothermal Field (TGF) located in the northwest of Turkey. CO2 has an acidic character in aqueous systems because it leads to the formation of carbonic acid. The injection of 20.6 m3/s CO2 (approximately 88 ppm) to hypersaline brine of TGF is a promising green approach for both mitigation of scaling by reducing pH from 7.2 to 6.2 at the well-head and the minimization of potential corrosion compared to the use of formic acid (55 ppm).

A new approach for predicting oil recovery factor during immiscible CO2 flooding in sandstones using dimensionless numbers

CO2 injection is one of the most promising techniques to enhance oil recovery. The most favorable properties of CO2 made this method popular and it has been widely used since 1950. Experimentally, the effect of CO2 injection on incremental oil recovery is widely measured by the core-flooding approach. An accurate estimation of the recovery factor is required to analyze the performance of the method to design the enhanced oil recovery method successfully. Hence, knowledge of the effects of different parameters on recovery is essential. Various reported experimental CO2 core-flooding data for the immiscible condition in sandstones were analyzed to develop the parametric relationships affecting ultimate oil recovery using data analytics. Selected data support a wide range of porosity (10.8–37.2%), permeability (1–18000 mD), injection pressure (2.73–11.44 MPa), injection rate (0.1–1.0 cm3/min), and crude oil types, which enhance the methodology used to develop more comprehensive dimensionless numbers and correlations to predict the oil recovery. Series of new dimensionless numbers were defined and used for the study to develop a correlation for predicting oil recovery factor. Capillary number, relative radius, injection pressure ratio, and oil composition number are used as dimensionless numbers in our approach. The oil recovery prediction by the developed correlation was in agreement with the experimental data. The proposed correlation shows that capillary number is the most effective parameter when predicting oil recovery.

The extraction effect of CO2 injection on the flow properties of crude oil

During CO2 flooding, extraction of lighter hydrocarbons from crude oil makes the remaining oil hard to be recovered. In this work, we design a new experimental method to characterize the effect of CO2 extraction on crude oil. The experimental results show that, the volume of extracted hydrocarbons increases as system pressure increases. The hydrocarbons with wider carbon number can be extracted from crude oil at high pressures. Moreover, the wax precipitation and viscosity of the remaining oil increase with increasing pressure. This study is expected to provide the basic understanding of the mechanisms of CO2 flooding for enhanced oil recovery.

Pore-Scale Modelling and Experiments on Drying Effects of CO2 Injection into Deep Saline Aquifer

Pore-Scale Modelling and Experiments on Drying Effects of CO2 Injection into Deep Saline Aquifer

The influence of CO2 on the structure of confined asphaltenes in calcite nanopores

The effect of CO2 injection on the structure and transport properties of confined asphaltenes in 6 nm slit-shaped calcite nanopore was studied using molecular dynamics simulations. The difference between asphaltene behavior in confined and bulk fluids in the presence of CO2 were investigated. A higher number of CO2 molecules in confinement influenced the anisotropic distribution of the confined hydrocarbons by displacing the adsorbed hydrocarbons molecules away from the pore surface toward the center of the pore. The van der Waals and electrostatic affinity of toluene and asphaltene with calcite surface decreased with an increase in the CO2 mole fraction. Increase in the number of CO2 molecules in confinement enhanced the tendency of asphaltenes to form aggregates. Further, the diffusivities of hydrocarbons were influenced by the density of injected CO2 and were found to vary anisotropically in the calcite nanopores. The aggregation of asphaltenes in the absence of confinement is faster as opposed to being in confinement. The enhanced adsorption of CO2 to the pore surface reduces the concentration of CO2 in the center of the pore resulting in slower aggregation of asphaltenes in confinement. These results suggest that developing a fundamental understanding of asphaltene behavior in confinement is essential for developing more robust predictions of field-scale observations of asphaltene aggregation.

Improved Design of the Lurgi Reactor for Methanol Synthesis Industry

AbstractCurrent studies are devoted to promote the production yield of the methanol synthesis process for treating large feed capacities in Algerian methanol manufacture industry by designing new reactor technologies. In order to achieve a high yield of methanol, the performance of methanol synthesis is improved by substituting the quench reactor by a new Lurgi reactor. The design of operating parameters of the Lurgi reactor involves the effect of CO2 injection on methanol production yield and the catalyst deactivation. The simulation results demonstrate that under the same industrial operating conditions the conversion rate of reactants increases from 23 % in the quench reactor to 37 % in the Lurgi reactor and the methanol yield can be increased by 33 % when substituting the quench reactor by the Lurgi reactor

Cement Bonded Particle Boards with Different Types of Natural Fibres—Using Carbon Dioxide Injection for Increased Initial Bonding

The effect of CO2 injection on initial strength increase and hardening of cement-fibre mix in a cement bonded particle board (CBPB) production was evaluated. Different cement contents, formation pressure and types of fibres were considered. The initial strength increase with CO2 injection is so much faster than this caused by conventional hydration that the produced samples do not need additional curing before they can be stored. Similar strength and stiffness values as in conventional products on the market are gained with lower cement content for similar types of fibres. Visual inspection of board surfaces aged for 13 years in a harsh exterior environment as well as comparison of strength and stiffness values for these boards when new and after ageing, gives a very satisfying result. The combined effect of the above discussed gains results in markedly increased productivity at lower cost and lower environmental impacts than is possible in traditional CBPB production.

The operation of reverse osmosis system with CO2 as a scale inhibitor: A study on operational behavior and membrane morphology

Fouling is one of the acute concerns during the application of reverse osmosis (RO) technology for wastewater reclamation. This study emphasizes the effectiveness of CO2 injection for scale inhibition on the surface of membranes during wastewater reclamation. The main objective of CO2 injection is to reduce pH of feed stream for avoiding inorganic scale precipitation. Two different experimental setups (lab- and pilot-scale) were installed and each was operated with four different RO modules including control (without any scale inhibitor), dosage of antiscalant, CO2 injection and simultaneous dosage of antiscalant and CO2 in an influent line. The pH of influent stream was reduced by CO2 purging at the level of 6 and 5. Data from operational setups, water analysis and morphological study of membrane from each module was used to establish comparative result. In comparison with other modules, the RO modules operated with CO2 were found successful to mitigate the inorganic scale formation on the surface of membrane. Furthermore, the RO modules operated with CO2 presented the successful restoration of system performance with clean-in-place.

Experimental assessment of pore fluid distribution and geomechanical changes in saline sandstone reservoirs during and after CO2 injection

Responsible CO2 geosequestration requires a comprehensive assessment of the geomechanical integrity of saline reservoir formations during and after CO2 injection. We assessed the geomechanical effects of CO2 injection and post-injection aquifer recharge on weakly cemented, synthetic-sandstone (38% porosity) sample in the laboratory under dry and brine-saturated conditions, before and after subjecting the sample to variable pore pressure brine-CO2 flow-through tests (∼170h). We measured ultrasonic P- and S-wave velocities (Vp, Vs) and attenuations, electrical resistivity and volumetric strain (εv). Vs was found to be an excellent indicator of mechanical deformation during CO2 injection; Vp gives mechanical and pore fluid distribution information, allowing quantification of the individual contribution of both phenomena when combined with resistivity. Abrupt strain recovery during imbibition suggests that aquifer recharge after ceasing CO2 injection might affect the geomechanical stability of the reservoir. Static and dynamic parameters indicate the sample experienced minor geomechanical changes during CO2 exposure, with an increase of Δεv <3% and a drop in ΔVs ∼1%. In contrast, due to brine-induced hydro-mechanical alteration, Δεv increased by ∼10% and ΔVs by ∼6%. This study provides a multiparameter, thermo-hydro-mechanical-chemical database needed to validate monitoring tools and simulators, for prediction of the geomechanical behaviour of CO2 storage reservoirs.

Simulation of CO2 injection in a small-scale pilot site in the Pohang Basin, Korea: Effect of dissolution rate of chlorite on mineral trapping

In Korea, a small-scale pilot project for CO2 injection was launched to target an offshore reservoir within the Pohang Basin. The objectives of this study are to present the effects of CO2 injection in a sloping aquifer on the evolution of the CO2 plume and its impact on mineral trapping using TOUGHREACT. The results show that the CO2 plume is asymmetrical and rapidly migrates along the slope in the up-dip direction from the injection well. With the migration of the CO2 plume, the increased acidity accelerates the water-rock interactions. As the CO2-water-rock interactions start quickly due to the rapid spreading of the CO2 plume, the amount of mineral trapping slightly increases due to the precipitation of siderite by chlorite dissolution. However, the stability of siderite is sensitive to the dissolution rate of chlorite. At low chlorite dissolution rates, siderite is more stable than ankerite in an undersaturated state. At high chlorite dissolution rates, ankerite is more stable because of the higher pH. In addition, the amount of mineral trapping increases considerably up to 3.7kg/m3, which is about 90 times that at the initial rate (0.04kg/m3). This simulation indicates that the uncertainty in the dissolution rate of chlorite must be considered when estimating the capacity of mineral trapping in situations in which iron-containing carbonate minerals significantly influence the mineral trapping.

Measurement and Visualization of Tight Rock Exposed to CO2 Using NMR Relaxometry and MRI

Understanding mechanisms of oil mobilization of tight matrix during CO2 injection is crucial for CO2 enhanced oil recovery (EOR) and sequestration engineering design. In this study exposure behavior between CO2 and tight rock of the Ordos Basin has been studied experimentally by using nuclear magnetic resonance transverse relaxation time (NMR T2) spectrum and magnetic resonance imaging (MRI) under the reservoir pressure and temperature. Quantitative analysis of recovery at the pore scale and visualization of oil mobilization are achieved. Effects of CO2 injection, exposure times and pressure on recovery performance have been investigated. The experimental results indicate that oil in all pores can be gradually mobilized to the surface of rock by CO2 injection. Oil mobilization in tight rock is time-consuming while oil on the surface of tight rock can be mobilized easily. CO2 injection can effectively mobilize oil in all pores of tight rock, especially big size pores. This understanding of process of matrix exposed to CO2 could support the CO2 EOR in tight reservoirs.

Evaluation of CO2 injection in shale gas reservoirs with multi-component transport and geomechanical effects

Although research on CO2 injection in shale gas reservoirs has been focused for enhanced gas recovery (EGR) and CO2 storage, previous studies have not examined both multi-component transport and geomechanical effects. Therefore, this study presents new shale gas models for CO2 injection considering multi-component adsorption, dissolution, molecular diffusion, and stress-dependent compaction. Based on these mechanisms and data for Barnett shale field, a simulation model was constructed for CO2 flooding and huff and puff. The proposed model was used to examine the effects of CO2 injection to EGR and CO2 storage and various mechanisms. The results presented that CO2 flooding and huff and puff improve CH4 production by 24% and 6% respectively compared with no injection scenario. At the end of simulated time, the injected CO2 is stored as free, adsorbed, and dissolved states in proportions of 42%, 55%, and 3% respectively. To confirm these results, Marcellus and New Albany shale models, which have different reservoir properties, are generated and compared with Barnett shale model. However, in Marcellus and New Albany shale models, effects of CO2 injection are lower than that of Barnett shale model. Therefore, to investigate factors affecting to the efficiency of CO2 injection in shale gas reservoirs, extensive simulations were performed. Results of the simulation analyses show that natural fracture permeability, hydraulic fracture half-length, well spacing, and Langmuir constants are significant factors for EGR and CO2 storage. For the real applications, these parameters should be mainly considered. The investigations performed in this study present better understanding of CO2 injection processes to EGR and CO2 storage and they are important for optimizing the designs of CO2 injection in field applications.

Modeling rock-fluid interactions due to CO2 injection into sandstone and carbonate aquifer considering salt precipitation and chemical reactions

Carbon dioxide is a greenhouse gas that has the most effect on the phenomenon of global warming. Saline aquifers have higher potential compared to other storage options to store carbon dioxide. Sandstone and carbonate aquifers have good reservoir characteristics and can be appropriate choices for CO2 storage. The modeling of the process has been performed combining salt precipitation, solubility, region specification and pressure drop models to study the effect of CO2 injection on gas saturation and pressure distribution profile, skin factor over time, the amount of salt precipitation, porosity and permeability. Sensitivity analysis has been done for temperature, pressure, permeability, porosity, salinity, critical gas saturation and CO2 injection rate. In order to study chemical reactions, long time simulation of rock-fluid interaction in carbonate and sandstone aquifer is also performed.The permeability reduction is in the range of 0.69–0.86 in all cases of salt precipitation simulation which is consistent with experimental results. The proposed salt precipitation model with an average relative deviation of about 5% for rock-fluid interaction parameters is able to predict the aquifer properties accurately during CO2 gas injection. The advantage of the model presented in this study compared to Zeidouni's model (2009) is that the proposed model predicts the pressure distribution after injection and estimates mole fraction of components in equilibrium with higher accuracy. The results of this study are shown that CO2 storage needs an aquifer with lower temperature, higher pressure and lower salinity compared to other options as the solubility trapping of carbon dioxide increases in this case. Permeability change does not influence on determining equilibrium regions and the only effect of the permeability is on the injectivity. Simulation of mineral reactions shows that chemical equilibrium is established after long time (more than 100 years) in sandstone aquifer and it is established in less than one day in carbonate aquifer. It should be noted that mineral trapping capacity of carbonate aquifer is less than sandstone aquifer in the CO2 storage process.

The Effects of CO2Injection 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 β-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, β-glucan, and PD. In conclusion, extruded barley and millet had higher potential for making value added cereal-based foods than the other cereals.

Modelling stress and strain in coal seams during CO2 injection incorporating the rock–fluid interactions

To reduce the adverse effects of global warming, geological sequestration has been suggested, which includes capturing and pumping anthropogenic CO2 into deep underground formations, such as coalbeds. Despite the advantages of coalbed sequestration, its geomechanical aspects are not well studied. In particular, the coupling between geomechanical and reservoir/adsorption behaviours of coal seam has been largely neglected. This paper aims to address this shortcoming by developing a coupled chemo-poro-mechanical model that predicts the geomechanical performance of a coal seam in which CO2 is being injected. Recent studies have shown that the interaction of CO2 and coal results in changes in geomechanical properties of coal, namely elastic modulus and peak strength. In order to investigate the significance of these changes in the geomechanical response of the storage site, an analytical solution was found to predict the distribution of stress within an axisymmetric reservoir, considering the effect of sorption-induced changes on mechanical behaviour. The analytical model was then coupled with a simplified dual porous reservoir simulation tool to study the effect of CO2 injection on reservoir and geomechanical performance of the coal seam. The results of the simulation showed that the changes in geomechanical properties of coal can significantly influence the stress and strain distributions within the formation, and therefore, the permeability distribution. Also, it was found that for the example simulated in this paper the adsorption induced reduction in strength did not influence the extent of the mechanical failure zone of the reservoir.

The Effect of CO2 on Wax Appearance Temperature of Crude Oils

Wax deposition makes up one of the main problems in the petroleum industry. Different types of techniques and treatments have been used to inhibit wax deposition. In this work, crude oils from Malaysian oil fields and Sudanese oil field are studied to determine their wax formation tendency for flow assurance purposes. In addition, effect of CO2 injection on the wax appearance temperature (WAT) for these crude oils is studied. In this paper, the high pressure micro differential scanning calorimetry (HPμDSC) has been employed in order to assess the WAT of the crude oils. Results showed that all these crude oils have a WAT ranging from 26.46 to 53.67°C. This suggests a likelihood of wax production in the reservoir and transportation pipelines. Experimental results showed that the injection of CO2 reduced the WAT of the crude oils to about 8.53°C below its original value.

Chemo-mechanical Modelling of Cemented Soils, from the Microscale to the Volume Element

Sensitivity of the mechanical properties of geomaterials to chemical processes is known to bring about either strengthening or weakening effects, the latter being critical for safety assessment in a number of civil and energy engineering applications. In this work, coupling of chemical and mechanical processes in bonded geomaterials is investigated by developing a micro-structure inspired model, which is then validated against a number of different chemo-mechanical experiments on calcarenite. The model is shown to provide a flexible framework for consistent interpretation of experimental loading paths, and can be readily applied to challenging boundary value problems, such as studying the stability of slopes exposed to acid rain or predicting the effectiveness of CO2 injection in carbonate rocks. The model can be also easily extended to materials involving cementation bonds with different composition.

Pilot scale autothermal gasification of coconut shell with CO2-O2 mixture

This paper explored the feasibility and benefit of CO2 utilization as gasifying agent in the autothermal gasification process. The effects of CO2 injection on reaction temperature and producer gas composition were examined in a pilot scale downdraft gasifier by varying the CO2/C ratio from 0.6 to 1.6. O2 was injected at an equivalence ratio of approximately 0.33–0.38 for supplying heat through partial combustion. The results were also compared with those of air gasification. In general, the increase in CO2 injection resulted in the shift of combustion zone to the downstream of the gasifier. However, compared with that of air gasification, the long and distributed high temperature zones were obtained in CO2-O2 gasification with a CO2/C ratio of 0.6–1.2. The progress of the expected CO2 to CO conversion can be implied from the relatively insignificant decrease in CO fraction as the CO2/C ratio increased. The producer gas heating value of CO2-O2 gasification was consistently higher than that of air gasification. These results show the potential of CO2-O2 gasification for producing high quality producer gas in an efficient manner, and the necessity for more work to deeply imply the observation.

Estimation of Carbon Dioxide Storage Capacity for Depleted Gas Reservoirs

The purpose of this study was to develop analytical equations to estimate CO2 storage capacity for depleted wet/dry gas reservoirs. The effects of CO2 injection on the changings of reservoir pressure and the mole fractions of CO2 and natural gas were studied from a verified pressure-volume-temperature process. There was a linear relationship between the corrected pressure term (pr/zmix) and the cumulative production term (Gpt-GinjCO2). The amount of CO2 storage can be analysed directly from the pr/zmix plot. The total volume of CO2 storage is larger than that of natural gas production from a depleted gas reservoir.