Flow field characters near fracture entrance in supercritical carbon dioxide sand fracturing

2019 ◽  
Vol 9 (5) ◽  
pp. 999-1009 ◽  
Author(s):  
Weiqiang Song ◽  
Junming Zhang ◽  
Chunguang Wang ◽  
Shaojie Chen ◽  
Zhongwei Chen
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Supercritical Carbon

Non-Uniform Two-Phase Flow of Supercritical Carbon Dioxide Centrifugal Compressor

2020 ◽  
Author(s):  
Wenrui Bao ◽  
Ce Yang ◽  
Li Fu ◽  
Changmao Yang ◽  
Lucheng Ji
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Centrifugal Compressor ◽  
Static Pressure ◽  
Leading Edge ◽  
Phase Region ◽  
Tip Clearance ◽  
Two Phase ◽  
Supercritical Carbon

Abstract An asymmetric structure of volute in a supercritical carbon dioxide centrifugal compressor induces a non-uniform circumferential distribution of the upstream flow field, which inevitably affects the formation of a two-phase region of carbon dioxide in an impeller. In this work, unsteady simulations for centrifugal compressors were conducted. First, the influence of low static strip induced by low static pressure near volute tongue on the impeller flow field was presented. Then, the non-uniform flow field distribution in the impeller passages and flow characteristics of the passages at the impeller inlet were obtained. Finally, the two-phase regions in the impeller were presented. The results demonstrate that for a centrifugal compressor with volute, the two-phase region appears not only on the suction surface of the leading edge of the blade, but also in some impeller passages, on the pressure surface of the blade near the leading edge, and in the leading edge and mid-chord of tip clearance, under the design conditions. The low static pressure strip induced by the volute leads to a high-speed region in the impeller passages where the temperature and pressure of supercritical carbon dioxide fall below the critical point and carbon dioxide enters the two-phase region. Meanwhile, the static pressure on the blade surface is distorted under the influence of a high-speed region in the passages, resulting in the formation of a two-phase region at the tip clearance. The flow distortion of passages at the impeller inlet results in the appearance of two-phase regions on the both sides of leading edge of the blade. The dryness on the suction side of the blade leading edge and the leading edge of the tip clearance is lower, which indicated that the proportion of liquid-phase carbon dioxide is higher in these two-phase regions.

Wellbore flow field of coiled tubing drilling with supercritical carbon dioxide

2017 ◽  
Vol 7 (4) ◽  
pp. 745-755 ◽  
Author(s):  
Weiqiang Song ◽  
Hongjian Ni ◽  
Ruihe Wang ◽  
Mengyun Zhao
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Coiled Tubing ◽  
Wellbore Flow ◽  
Supercritical Carbon

Numerical simulation of the abrasive supercritical carbon dioxide jet: The flow field and the influencing factors

2016 ◽  
Vol 28 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Zhen-guo He ◽  
Gen-sheng Li ◽  
Hai-zhu Wang ◽  
Zhong-hou Shen ◽  
Shou-ceng Tian ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Influencing Factors ◽  
Supercritical Carbon

scholarly journals The Flow Characteristics of Supercritical Carbon Dioxide (SC-CO2) Jet Fracturing in Limited Perforation Scenarios

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2627
Author(s):  
Can Cai ◽  
Song Xie ◽  
Qingren Liu ◽  
Yong Kang ◽  
Dong Lian ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Numerical Model ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Total Pressure ◽  
Strong Mixing ◽  
High Speed Photography ◽  
Promising Alternative ◽  
Supercritical Carbon

Supercritical carbon dioxide (SC-CO2) jet fracturing is a promising alternative for shale gas fracturing instead of water. However, most studies pay more attention to the fracture generation and ignore the flow characteristic of SC-CO2 jet fracturing in limited perforation scenarios. To accurately explore the flow field in a limited perforation tunnel, a numerical model of a SC-CO2 jet in a limited perforation tunnel before fracture initiation is established based on the corresponding engineering background. The comparison between the numerical simulation and experiments has proved that the model is viable for this type of analysis. By using the numerical method, the flow field of the SC-CO2 jet fracturing is analyzed, and influencing factors are discussed later. The verification and validation show that the numerical model is both reliable and accurate. With the dramatic fluctuating of turbulent mixing in a fully developed region, there is an apparent increase in the CO2 density and total pressure during limited perforation. When the z increases from 10 times r0 to 145 times r0, the velocity on the perforation wall surface would decrease below 0 m/s, resulting in backflow in the perforation tunnel. The structure of the nozzle, including the outlet length and outlet diameters, significantly affects the axial velocity and boosting pressure in the perforation tunnel. The highest total pressure exists when the nozzle length-to-radius ratio is 2. The maximum velocity of the jet core drops from 138.7 to 78 m/s, and the “hydraulic isolating ring” starts disappearing when the radius changes from 1 to 1.5 mm. It is necessary to increase the aperture ratio as much as possible to ensure pressurization but not over 1. Based on a similar theory high-speed photography results clearly show that the SC-CO2 develops to fully jetting in only 0.07 s and a strong mixing exists in the annular region between the jet core and the surroundings, according with the numerical simulation. This study should be helpful for scholars to comprehensively understand the interaction between the SC-CO2 jet and perforation, which is beneficial for studying SC-CO2 fracturing.

Calculation and verification of flow field in supercritical carbon dioxide dry gas seal based on turbulent adiabatic flow model

2022 ◽  
Vol 165 ◽  
pp. 107275
Author(s):  
Ruqi Yan ◽  
Hanqing Chen ◽  
Weizheng Zhang ◽  
Xianzhi Hong ◽  
Xin Bao ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Flow Model ◽  
Dry Gas Seal ◽  
Adiabatic Flow ◽  
Supercritical Carbon

Flow field simulation of supercritical carbon dioxide jet: Comparison and sensitivity analysis*

2015 ◽  
Vol 27 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Hai-zhu Wang ◽  
Gen-sheng Li ◽  
Shou-ceng Tian ◽  
Yu-xiong Cheng ◽  
Zhen-guo He ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sensitivity Analysis ◽  
Supercritical Carbon Dioxide ◽  
Flow Field ◽  
Flow Field Simulation ◽  
Field Simulation ◽  
Supercritical Carbon
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