scholarly journals Experimental study of CO2 injectivity impairment in sandstone due to salt precipitation and fines migration

Author(s):  
Muhammad Aslam Md Yusof ◽  
Yen Adams Sokama Neuyam ◽  
Mohamad Arif Ibrahim ◽  
Ismail M. Saaid ◽  
Ahmad Kamal Idris ◽  
...  

AbstractRe-injection of carbon dioxide (CO2) in deep saline formation is a promising approach to allow high CO2 gas fields to be developed in the Southeast Asia region. However, the solubility between CO2 and formation water could cause injectivity problems such as salt precipitation and fines migration. Although both mechanisms have been widely investigated individually, the coupled effect of both mechanisms has not been studied experimentally. This research work aims to quantify CO2 injectivity alteration induced by both mechanisms through core-flooding experiments. The quantification injectivity impairment induced by both mechanisms were achieved by varying parameters such as brine salinity (6000–100,000 ppm) and size of fine particles (0–0.015 µm) while keeping other parameters constant, flow rate (2 cm3/min), fines concentration (0.3 wt%) and salt type (Sodium chloride). The core-flooding experiments were carried out on quartz-rich sister sandstone cores under a two-step sequence. In order to simulate the actual sequestration process while also controlling the amount and sizes of fines, mono-dispersed silicon dioxide in CO2-saturated brine was first injected prior to supercritical CO2 (scCO2) injection. The CO2 injectivity alteration was calculated using the ratio between the permeability change and the initial permeability. Results showed that there is a direct correlation between salinity and severity of injectivity alteration due to salt precipitation. CO2 injectivity impairment increased from 6 to 26.7% when the salinity of brine was raised from 6000 to 100,000 ppm. The findings also suggest that fines migration during CO2 injection would escalate the injectivity impairment. The addition of 0.3 wt% of 0.005 µm fine particles in the CO2-saturated brine augmented the injectivity alteration by 1% to 10%, increasing with salt concentration. Furthermore, at similar fines concentration and brine salinity, larger fines size of 0.015 µm in the pore fluid further induced up to three-fold injectivity alteration compared to the damage induced by salt precipitation. At high brine salinity, injectivity reduction was highest as more precipitated salts reduced the pore spaces, increasing the jamming ratio. Therefore, more particles were blocked and plugged at the slimmer pore throats. The findings are the first experimental work conducted to validate theoretical modelling results reported on the combined effect of salt precipitation and fines mobilisation on CO2 injectivity. These pioneering results could improve understanding of CO2 injectivity impairment in deep saline reservoirs and serve as a foundation to develop a more robust numerical study in field scale.

2021 ◽  
Author(s):  
Muhammad Aslam Md Yusof ◽  
Mohamad Arif Ibrahim ◽  
Muhammad Azfar Mohamed ◽  
Nur Asyraf Md Akhir ◽  
Ismail M Saaid ◽  
...  

Abstract Recent studies indicated that reactive interactions between carbon dioxide (CO2), brine, and rock during CO2 sequestration can cause salt precipitation and fines migration. These mechanisms can severely impair the permeability of sandstone which directly affect the injectivity of supercritical CO2 (scCO2). Previous CO2 injectivity change models are ascribed by porosity change due to salt precipitation without considering the alteration contributed by the migration of particles. Therefore, this paper presents the application of response surface methodology to predict the CO2 injectivity change resulting from the combination of salt precipitation and fines migration. The impacts of independent and combined interactions between CO2, brine, and rock parameters were also evaluated by injecting scCO2 into brine saturated sandstone. The core samples were saturated with NaCl brine with salinity between 6,000 ppm to 100,000 ppm. The 0.1, 0.3, and 0.5 wt.% of different-sized hydrophilic silicon dioxide particles (0.005, 0.015, and 0.060 μm) were added to evaluate the effect of fines migration on CO2 injectivity alteration. The pressure drop profiles were recorded throughout the injection process and the CO2 injectivity alteration was represented by the ratio between the initial and final injectivity. The experimental results showed that brine salinity has a greater individual influence on permeability reduction as compared to the influence of particles (jamming ratio and particle concentration) and scCO2 injection flow rate. Moreover, the presence of both fines migration and salt precipitation during CO2 injection was also found to intensify the permeability reduction by 10%, and reaching up to threefold with increasing brine salinity and particle size. The most significant reductions in permeability were observed at higher brine salinities, as more salts are being precipitated out which, in turn, reduces the available pore spaces and leads to a higher jamming ratio. Thus, more particles were blocked and plugged especially at the slimmer pore throats. Based on comprehensive 45 core flooding experimental data, the newly developed model was able to capture a precise correlation between four input variables (brine salinity, injection flow rate, jamming ratio, and particle concentration) and CO2 injectivity changes. The relationship was also statistically validated with reported data from five case studies.


Author(s):  
Imtiaz Ahmad ◽  
Aly R. Seadawy ◽  
Hijaz Ahmad ◽  
Phatiphat Thounthong ◽  
Fuzhang Wang

Abstract This research work is to study the numerical solution of three-dimensional second-order hyperbolic telegraph equations using an efficient local meshless method based on radial basis function (RBF). The model equations are used in nuclear material science and in the modeling of vibrations of structures. The explicit time integration technique is utilized to semi-discretize the model in the time direction whereas the space derivatives of the model are discretized by the proposed local meshless procedure based on multiquadric RBF. Numerical experiments are performed with the proposed numerical scheme for rectangular and non-rectangular computational domains. The proposed method solutions are converging quickly in comparison with the different existing numerical methods in the recent literature.


2019 ◽  
Author(s):  
Mohammad Haftani ◽  
Chenxi Wang ◽  
Jesus David Montero Pallares ◽  
Mahdi Mahmoudi ◽  
Vahidoddin Fattahpour ◽  
...  

Author(s):  
Heng Zhou ◽  
Xu Tian ◽  
Mingyin Kou ◽  
Shengli Wu ◽  
Yansong Shen

SPE Journal ◽  
2013 ◽  
Vol 18 (03) ◽  
pp. 534-544 ◽  
Author(s):  
M.. Ahmadi ◽  
A.. Habibi ◽  
P.. Pourafshary ◽  
S.. Ayatollahi

Summary Fines migration is a noticeable problem in petroleum-production engineering. Plugging of throats in porous media occurs because of detachment of fine particles from sand surfaces. Thus, the study of interactions between fines and pore surfaces and the investigation of governing forces are important factors to consider when describing the mechanism of the fines-release process. The main types of these forces are electric double-layer repulsion (DLR) and London–van der Waals attraction (LVA). It may be possible to alter these forces with nanoparticles (NPs) as surface coatings. In comparison with repulsion forces, NPs increase the effect of attraction forces. In this paper, we present new experiments and simple modeling to observe such properties of NPs. For this purpose, the surfaces of pores were coated with different types of NPs: magnesium oxide (MgO), silicon dioxide (SiO2), and aluminum oxide (Al2O3). A zeta-potential test was used to examine changes in the potential of the pore surfaces. Total interaction energy was then mathematically calculated to compare different states. Total interaction energy is a fitting criterion that gives proper information about the effect of different NPs on surface properties. Consequently, total interaction plots are found to be suitable tools for selecting the best coating material. On the basis of experimental results, the magnitude of change in zeta potential for the MgO NP was 45 mV. Our model demonstrated that the magnitude of the electric DLR in comparison with the LVA of the probe and plate surface was considerably diminished when MgO NPs were used to coat the surface of the plate, which agrees completely with our experimental observation.


2021 ◽  
Vol 13 (9) ◽  
pp. 4748
Author(s):  
Edwin Villagran ◽  
Carlos Bojacá ◽  
Mohammad Akrami

The use of covered structures is an alternative increasingly used by farmers to increase crop yields per unit area compared to open field production. In Latin American countries such as Colombia, productive areas are located in with predominantly hillside soil conditions. In the last two decades, farmers have introduced cover structures adapted to these soil conditions, structures for which the behavior of factors that directly affect plant growth and development, such as microclimate, are still unknown. Therefore, in this research work, a CFD-3D model successfully validated with experimental data of temperature and air velocity was implemented. The numerical model was used to determine the behavior of air flow patterns and temperature distribution inside a Colombian passive greenhouse during daytime hours. The results showed that the slope of the terrain affects the behavior of the air flow patterns, generating thermal gradients inside the greenhouse with values between 1.26 and 16.93 °C for the hours evaluated. It was also found that the highest indoor temperature values at the same time were located in the highest region of the terrain. Based on the results of this study, future researches on how to optimize the microclimatic conditions of this type of sustainable productive system can be carried out.


Author(s):  
Fu-qiang Chen ◽  
Zhi-xin Gao ◽  
Jin-yuan Qian ◽  
Zhi-jiang Jin

In this paper, a new high multi-stage pressure reducing valve (HMSPRV) is proposed. The main advantages include reducing noise and vibration, reducing energy consumption and dealing with complex conditions. As a new high pressure reducing valve, its flow characteristics need to be investigated. For that the valve opening has a great effect on steam flow, pressure reduction and energy consumption, thus different valve openings are taken as the research points to investigate the flow characteristics. The analysis is conducted from four aspects: pressure, velocity, temperature fields and energy consumption. The results show that valve opening has a great effect on flow characteristics. No matter for pressure, velocity or temperature field, the changing gradient mainly reflects at those throttling components for all valve openings. For energy consumption, in the study of turbulent dissipation rate, it can be found that the larger of valve opening, the larger of energy consumption. It can be concluded that the new high multi-stage pressure reducing valve works well under complex conditions. This study can provide technological support for achieving pressure regulation, and benefit the further research work on energy saving and multi-stage design of pressure reducing devices.


DYNA ◽  
2019 ◽  
Vol 86 (210) ◽  
pp. 164-173
Author(s):  
Carlos Andrés Caro Camargo ◽  
Oscar Fabián Pacheco Merchán ◽  
Hans Paul Sánchez Tueros

The purpose of this research work was to calibrate the Manning's roughness coefficient in rural non-instrumented basins using a distributed hydrological model. The process consisted of the selection of several basins with vegetal cover of forests and grasslands, and its subsequent experimental numerical study, in which the hydrological response hydrograph of each reference basin was obtained from the HEC-HMS software and the hydrograph to be calibrated was the Iber software, which is a hydrodynamic model based on the two-dimensional Saint Venant equations, solved by the finite volume method. Once the calibration process was carried out, the roughness coefficients with the best fit for each basin were identified with increases in precipitation, identifying the limitations of these values and the standard model used.


SPE Journal ◽  
2018 ◽  
Vol 23 (03) ◽  
pp. 998-1018 ◽  
Author(s):  
Bin Yuan ◽  
Rouzbeh Ghanbarnezhad Moghanloo

Summary Prediction of how nanofluid applications can potentially control fines migration in porous media saturated with two immiscible fluids requires a mechanistic modeling approach. We develop analytic solutions to evaluate the efficiency of nanofluid utilization to reduce fines migration in systems saturated with two immiscible fluids. In this study, fines migration in the radial-flow system saturated with two immiscible fluids (oil and water) is considered; two capture mechanisms of fine particles—fines attachment and straining—are incorporated into the modeling work. The analytic solution is derived by implementing the splitting method and stream-function transformation to convert a 2 × 2 (nonhomogeneous) system of equations into an equation with a fine-particle component (nanoparticle effects) and a lifting equation in which only water saturation appears. Through quantitative comparison of suspended fines and water-saturation-profile plots, the accuracy of the analytic solution is verified with finite-difference numerical solutions. Saturation c-shock and saturation s-shock appear in the analytical solutions. The fines migration and consequent phenomena (fines attachment, fines straining, and fines suspension) decelerate the breakthrough of the injected fluids (better sweep efficiency) and increase the corresponding front saturation of the injected fluid near the wellbore—i.e., larger relative permeability (better injectivity). The results suggest that fines attachment onto the grain surface and well injectivity are enhanced after nanofluid pretreatment; moreover, the smallest radius to be pretreated by nanofluid is approximated to maintain its benefits. In practice, our analytic approach provides a valuable mathematical structure to evaluate how nanoparticle usage can enhance performance of water-based enhanced-oil-recovery (EOR) techniques in reservoirs with a fines-migration issue.


Author(s):  
Farhad Behnamfar ◽  
Hadi Rafizadeh ◽  
Mortza Omidi

This research work presents new details for moment connections in precast concrete structures satisfying both design and practice criteria. In this paper the results of the numerical study on the connections are presented. For the analysis, the ANSYS software is selected because of its diversity in nonlinear analysis. By calculating the monotonic load-displacement curve of each connection, the connections are evaluated for their stiffness, strength, and ductility. The compressive strength of the connection concrete is taken to be 30, 35 and 40 MPa, for each round of analysis. The results of the analysis show that the proposed connections are stiff enough to be moment resisting and to be emulating an equivalent monolithic, or basic connection. It is illustrated that the connections are stronger but somewhat less ductile than the basic connection regardless of the concrete strengths examined. Moreover, it is shown that in each precast connection while increasing the compressive strength of concrete does not affect the connection stiffness considerably, it increases the ultimate load and ductility of the connection. As a main result of this study, the suggested connection details are categorized based on their stiffness, strength, and ductility. The suggested connections can be used in moment resisting precast concrete buildings based on the desired strength and ductility.


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