The Sensitivity Analysis of Wellbore Heat Transfer during the CO2 Injection Process

2014 ◽  
Vol 889-890 ◽  
pp. 1638-1643
Author(s):  
Yi Zhang ◽  
Tong Tong Li ◽  
Yong Chen Song ◽  
Duo Li ◽  
Yang Chun Zhan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Sensitivity Analysis ◽  
Flow Rate ◽  
Injection Pressure ◽  
Simulation Method ◽  
Injection Process ◽  
Injection Flow ◽  
Injection Temperature ◽  
Thomson Coefficient

The sensitivity analysis of wellbore heat transfer during the CO2injection process is of vital importance to Carbon dioxide utilization and sequestration (CCUS). A numerical simulation method is developed to simulate the process of wellbore heat transfer during injecting carbon dioxide by amending the classical heat transfer modelRamey models. It analyses how the selected parameters affect the distribution of the wellbore temperature and pressure, which include CO2injection temperature, pressure and density, the injection flow rate and Joule Thomson coefficient. The results show that, CO2injection temperature has greater impact on the initial level of the temperature distribution; higher injection pressure raises the temperature mainly because of the effect of Joule Thomson coefficient; also, when the injection process lasts a longer time, the distribution is much more stable. When the injection flow rate is higher, the strata temperature has less influence on the flow temperature. The injection pressure and density has very appreciable effect on the pressure distribution. However, the other parameters have less influence on it. The modified simulation method was applied in Jiangsu Caoshe oil field and the simulation results coincided with the measuring data well.

Joule-Thomson Effect on Heat Transfer in CO2 Injection Wellbore

2013 ◽  
Vol 734-737 ◽  
pp. 1411-1414
Author(s):  
Yi Zhang ◽  
Cheng Hu ◽  
Yong Chen Song
Keyword(s):  
Heat Transfer ◽  
Fluid Pressure ◽  
Pressure Rise ◽  
Injection Pressure ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Fluid Temperature ◽  
Thomson Effect ◽  
Injection Temperature ◽  
Thomson Coefficient

Ramey model is a classical wellbore heat transfer model. However Ramey model did not consider Joule-Thomson effect. In this paper, Ramey model is improved by considering Joule-Thomson effect. The results show that Joule-Thomson effect will cause fluid temperature higher due to a positive Joule-Thomson coefficient and pressure rise. Injection temperature has little effect on fluid temperature. Fluid pressure is influenced by fluid viscidity. Higher injection pressure leads to faster pressure increasing speed.

Unloading Frac Hits in Gas Wells: How Does the Nitrogen Injection Rate and Pressure Affect the Unloading Process?

2021 ◽  
Author(s):  
Miguel Angel Cedeno
Keyword(s):  
Multiphase Flow ◽  
Flow Rate ◽  
Injection Pressure ◽  
Injection Rate ◽  
Gas Wells ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Nitrogen Injection ◽  
Injection Flow ◽  
Transient Multiphase Flow

Abstract The unconventional resources development has grown tremendously as a result of the advancement in horizontal drilling technology coupled with hydraulic fracturing. However, as more wells are drilled and fractured close to each other, frac hits have become a major challenge in these wells. The aim of this work is to investigate the effect of nitrogen injection flow rate and pressure on unloading frac hits gas wells in transient multiphase flow. A numerical simulation model was created using a transient multiphase flow simulator to mimic the unloading process of frac hits by injecting nitrogen from the surface through the annulus section of the well. Many simulation cases were created and analyzed to comprehend the effect of the nitrogen injection rate and pressure on the unloading of frac hits. The model mimicked real field data from currently active well in the Eagle Ford Shale. The results showed that as the nitrogen injection pressure increases, the nitrogen volume and the time to unload the frac hits decrease. On the other hand, increasing the injection rate of nitrogen will increase the nitrogen volume required to unload the frac hits. In addition, the time to unload frac hits will be decreased as the nitrogen injection rate increases. These results indicate that the time required to unload frac hits will be minimized if higher flow rates of nitrogen were utilized. Nonetheless, the volume of nitrogen required to unload the frac hits will be maximized. An important observation to highlight is that the operators can save money by reducing the time for injecting nitrogen. This observation was verified when increasing the injection pressure in the frac hit well in the Eagle Ford Shale, the time of injection was reduced 20%. This study presents the effects of nitrogen injection flow rate and injection pressure for unloading frac hits in gas wells. Due to the lack of published studies about this topic, this work can serve as a practical guideline for unloading frac hits in gas wells.

Effects of Molding Parameters on MIM’s Material Distribution using Numerical Simulation Method

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Mohd Fazuri Abdullah ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Muhamad Afkar Husin
Keyword(s):  
Injection Molding ◽  
Flow Rate ◽  
Computer Aided Design ◽  
Manufacturing Industry ◽  
Injection Pressure ◽  
Global Market ◽  
Element Analysis ◽  
Percentage Difference ◽  
Filling Time ◽  
Injection Temperature

In the competitive world in the global market, manufacturing industry is striving to produce products at high quality, shorter time and low cost. This can be achieved through proper design activities, with assist of finite element analysis (FEA) and computer aided design (CAD). The objective of this project is to study the effect of the molding parameters on the physical characteristics of surgery tool via MIM based on design of experiment (Taguchi method). This numerical results show the behavior of feedstock entering the mould during injection process and the possibility defects that might occur. The quality of the injected product depends on the selection of the feedstock as well as the parameters for injection molding such as injection temperature (A), mold temperature (B), flow rate (C) and injection pressure (D). From the analysis of Taguchi, the optimal levels of process parameters for the shortest filling time is [A3(200ºC), B1(80ºC), C3(20 cm3/s), D3(260 MPa)]. Set of optimal parameters for the smallest shrinkage percentage difference is [A1(180ºC), B3(100ºC), C3(20 cm3/s), D2(255 MPa)]. The most influence injection molding parameters are injection temperature and injection pressure. Follow by the flow rate.

scholarly journals Effect of the Pumping-injection flow rate on Heat Transfer Characteristic of Borehole Heat Exchangers for Coupling Ground-Source Heat Pump System

2020 ◽  
Author(s):  
Jiuchen Ma ◽  
Qian Jiang ◽  
Qiuli Zhang ◽  
Yacheng Xie ◽  
Yahui Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Transfer Characteristic ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Injection Flow Rate ◽  
Injection Flow ◽  
Ground Source

Abstract A coupling ground source heat pump system (CGSHP) is established in areas where groundwater is shallow but the seepage velocity is weak, which sets up pumping and injection wells on both sides of borehole heat exchangers (BHEs). A convection-dispersion analytical model of excess temperature in aquifer that considers groundwater forced seepage and axial effects and thermal dispersion effects is proposed. A controllable forced seepage sandbox is built by equation analysis method and similarity criteria. Through indoor test and the proposed analytical model, the correctness and accuracy of the numerical simulation software FEFLOW7.1 is verified. The influence of different pumping-injection flow rate on the heat transfer characteristic of BHEs is studied by numerical simulation. The results show that the average heat efficiency coefficient of BHEs increases and the heat influence range of downstream BHEs expands with the increasing of pumping-injection flow rate. The relation curve between Pe and the increment of heat transfer rate per unit depth of BHEs (Δ`q) is distributed as Gaussian function. The pumping-injection flow rate that makes Darcy velocity reaches 0.6×10-6~1.4×10-6 m∙s-1 in the aquifer is the best reference range for CGSHP system，so 400~600 m3∙d-1 is taken as the best pumping-injection flow rate in this paper.

scholarly journals Effect of the Pumping-injection flow rate on Heat Transfer Characteristic of Borehole Heat Exchangers for Coupling Ground-Source Heat Pump System

2020 ◽  
Author(s):  
Jiuchen Ma ◽  
Qian Jiang ◽  
QuLi Zhang ◽  
Yacheng Xie ◽  
Yahui Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Transfer Characteristic ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Injection Flow Rate ◽  
Injection Flow ◽  
Ground Source

Abstract A coupling ground source heat pump system (CGSHP) is established in areas where groundwater is shallow but the seepage velocity is weak, which sets up pumping and injection wells on both sides of borehole heat exchangers (BHEs). A convection-dispersion analytical model of excess temperature in aquifer that considers groundwater forced seepage and axial effects and thermal dispersion effects is proposed. A controllable forced seepage sandbox is built by equation analysis method and similarity criteria. Through indoor test and the proposed analytical model, the correctness and accuracy of the numerical simulation software FEFLOW7.1 is verified. The influence of different pumping-injection flow rate on the heat transfer characteristic of BHEs is studied by numerical simulation. The results show that the average heat efficiency coefficient of BHEs increases and the heat influence range of downstream BHEs expands with the increasing of pumping-injection flow rate. The relation curve between Pe and the increment of heat transfer rate per unit depth of BHEs (Δ`q) is distributed as Gaussian function. The pumping-injection flow rate that makes Darcy velocity reaches 0.6 × 10− 6~1.4 × 10− 6 m∙s− 1 in the aquifer is the best reference range for CGSHP system,so 400 ~ 600 m3∙d− 1 is taken as the best pumping-injection flow rate in this paper.

Prediction of Tool-Chip Interface Temperature in Cryogenic Machining of Ti–6Al–4V: Analytical Modeling and Sensitivity Analysis

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Sinan Kesriklioglu ◽  
Frank E. Pfefferkorn
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
Liquid Nitrogen ◽  
Flow Rate ◽  
Cutting Speed ◽  
Design Parameters ◽  
Interface Temperature ◽  
Cryogenic Machining ◽  
Cooling Strategy ◽  
Cutting Insert

Abstract The goal of this work is to predict the tool-chip interface temperature during cryogenic machining and determine the effectiveness of this cooling strategy. Knowledge of the tool-chip interface temperature is needed to conduct process planning: choosing a tool cooling geometry, cutting speed, and cryogen flow rate as well as predicting tool life and achievable material removal rate. A detailed explanation of the analytical heat transfer model is presented, which is a modified form of Loewen and Shaw's orthogonal cutting model, where a thermal resistance network is applied to represent the heat transfer mechanisms in, and out of, the cutting tool. An in-depth discussion of the temperature rise at the tool-chip interface during orthogonal machining of titanium alloy Ti–6Al–4V is presented. The effect of cutting speed, cryogen flow rate and quality, and cooling strategy are explored. The model is used to compare the effect of internal cryogenic cooling with external flood cooling using a water-based metalworking fluid or liquid nitrogen. A sensitivity analysis of the model is conducted and ranks the relative importance of various design parameters. The thermal conductivity of the cutting insert has the greatest influence on the predicted interface temperature. The low boiling temperature and phase change are what make internal cooling of a cutting insert with liquid nitrogen effective at reducing the tool-chip interface temperature. If the heat flowing into the tool, from the tool-chip interface, does not exceed the available latent heat in the cryogen, then this method is more effective than external flood cooling.

Evaluation of Processing Effects in Injection Molded Thermoplastics Using Excimer Laser

2004 ◽  
Author(s):  
E. Sancaktar ◽  
N. Negandhi ◽  
S. Adwani
Keyword(s):  
Weight Loss ◽  
Laser Ablation ◽  
Flow Rate ◽  
Annealing Time ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Injection Flow Rate ◽  
Injection Flow ◽  
Injection Molded ◽  
Processing Effects

The ablation behavior of amorphous (polystyrene (PS), and polycarbonate (PC)) and crystalline (poly(ethylene terephthalate) (PET), and glass filled poly(butylenes terephthalate) (PBT)) polymers by 248 nm KrF excimer laser irradiation were investigated for different injection molding conditions namely, injection flow rate, injection pressure, and mold temperature, as a possible method to evaluate the processing effects in the specimens. For this purpose, dumb-bell shaped samples were injection molded at different sets of processing conditions, and weight loss measurements were carried out for the different injection molding conditions. Some of the crystalline (PET) samples were annealed at different annealing time and temperature. For PET, weight loss decreased with increasing mold temperature and remained insensitive to injection flow rate. Annealing time and temperature significantly reduced weight loss in PET. For PBT, the weight loss due to laser ablation reduced with increase in material packing due to pressure, and also showed some sensitivity to flow rate variation. The major effect was seen with glass filled PBT samples. The weight loss decreased drastically with increasing glass fiber content. Laser ablation allowed observation of process induced fiber orientation by SEM in PBT samples. For PS and PC, the weight loss increased with increases in the injection flow rate and mold temperature, and decreased with increasing injection pressure. Position near the gate showed higher ablation than the position at the end for all the conditions. A decrease in the material orientation, with injection speed and mold temperature, led to increase in the weight loss, while increase in the injection pressure, and consequently orientation, led to lower weight loss for PS and PC. Higher residual stress samples showed higher weight loss.

scholarly journals Evaluating Reservoir Risks and Their Influencing Factors during CO2 Injection into Multilayered Reservoirs

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Lu Shi ◽  
Bing Bai ◽  
Haiqing Wu ◽  
Xiaochun Li
Keyword(s):  
Flow Rate ◽  
Risk Evaluation ◽  
Carbon Capture ◽  
Lower Layer ◽  
Carbon Capture And Storage ◽  
Injection Pressure ◽  
Co2 Injection ◽  
Rate Distribution ◽  
Injection Flow ◽  
And Storage

Wellbore and site safety must be ensured during CO2 injection into multiple reservoirs during carbon capture and storage projects. This study focuses on multireservoir injection and investigates the characteristics of the flow-rate distribution and reservoir-risk evaluation as well as their unique influences on multireservoir injection. The results show that more CO2 enters the upper layers than the lower layers. With the increase in injection pressure, the risks of the upper reservoirs increase more dramatically than those of the low reservoirs, which can cause the critical reservoir (CR) to shift. The CO2 injection temperature has a similar effect on the injection flow rate but no effect on the CR’s location. Despite having no effect on the flow-rate distribution, the formation-fracturing pressures in the reservoirs determine which layer becomes the CR. As the thickness or permeability of a layer increases, the inflows exhibit upward and downward trends in this layer and the lower layers, respectively, whereas the inflows of the upper layers remain unchanged; meanwhile, the risks of the lower layer and those of the others decrease and remain constant, respectively. Compared to other parameters, the reservoir porosities have a negligible effect on the reservoir risks and flow-rate distributions.

scholarly journals Effect of the Pumping-injection flow rate on Heat Transfer Characteristic of Borehole Heat Exchangers for Coupling Ground-Source Heat Pump System

2020 ◽  
Author(s):  
Jiuchen Ma ◽  
Qian Jiang ◽  
Qiuli Zhang ◽  
Yacheng Xie ◽  
Yahui Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Transfer Characteristic ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Injection Flow Rate ◽  
Injection Flow ◽  
Ground Source

Abstract A coupling ground source heat pump system (CGSHP) is established in areas where groundwater is shallow but the seepage velocity is weak, which sets up pumping and injection wells on both sides of borehole heat exchangers (BHEs). A convection-dispersion analytical model of excess temperature in aquifer that considers groundwater forced seepage and axial effects and thermal dispersion effects is proposed. A controllable forced seepage sandbox is built by equation analysis method and similarity criteria. Through indoor test and the proposed analytical model, the correctness and accuracy of the numerical simulation software FEFLOW7.1 is verified. The influence of different pumping-injection flow rate on the heat transfer characteristic of BHEs is studied by numerical simulation. The results show that the average heat efficiency coefficient of BHEs increases and the heat influence range of downstream BHEs expands with the increasing of pumping-injection flow rate. The relation curve between Pe and the increment of heat transfer rate per unit depth of BHEs (Δ‾ q ) is distributed as Gaussian function. The pumping-injection flow rate that makes Darcy velocity reaches 0.6×10 -6 ~1.4×10 -6 m∙s -1 in the aquifer is the best reference range for CGSHP system,so 400~600 m 3 ∙d -1 is taken as the best pumping-injection flow rate in this paper.

The Use of Foreign Gas to Simulate the Effects of Density Ratios in Film Cooling

1989 ◽  
Vol 111 (1) ◽  
pp. 57-62 ◽  
Author(s):  
A. J. H. Teekaram ◽  
C. J. P. Forth ◽  
T. V. Jones
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Film Cooling ◽  
Density Ratio ◽  
Superposition Model ◽  
Carbon Dioxide Injection ◽  
Injection Flow ◽  
Wall Boundary Conditions ◽  
Isothermal Wall ◽  
Density Ratios

This paper provides a unique experimental assessment of the use of a foreign gas to vary the injection-to-mainstream density ratio in film-cooling experiments. It is widely recognized that it is important to scale both the velocity and density field in such tests in order that they will be representative of conditions in the gas turbine. Where it is difficult to achieve the temperature required for the correct injection-to-mainstream density ratio, some experimental techniques resort to the use of a heavier foreign gas to simulate the colder injection flow. In the experiment reported, the Isentropic Light Piston Tunnel has provided an environment in which a desired injection-to-mainstream density ratio can be achieved both by varying the temperature of the two airstreams and by using a heavier injection gas, carbon dioxide. Direct heat transfer measurements, which do not require the use of a mass transfer analogy, are taken. Use of the superposition model of film cooling allows the results to be interpreted easily to yield heat transfer parameters all obtained under isothermal wall boundary conditions. Comparison of results for air and carbon dioxide injection show that with this approach, it is possible to use a foreign injection gas to simulate the required injection-to-freestream density ratio.

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