High Pressure
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2021 ◽  
pp. 152660282110586
Yu Li ◽  
Wenhao Cui ◽  
Jukun Wang ◽  
Chao Zhang ◽  
Tao Luo

Objective: The objective of the present study was to compare the effectiveness of high-pressure balloon (HPB) versus conventional balloon (CB) angioplasty in treating arteriovenous fistula (AVF) stenosis. Materials and Methods: A meta-analysis was conducted using data acquired from PubMed, EMBASE, the Cochrane Library, SinoMed, CNKI, WanFang, and VIP databases from the time the databases were established to December 2020. All analyses included in the studies comprised the subgroups of HPB and CB. The patency rates of AVF were compared between 2 groups at 3, 6, and 12 months after operation. Results: Seven studies comprising 364 patients were included in the meta-analyses. The pooled results revealed that restenosis rate of AVFs treated with HPB was significantly lower than that of AVFs treated with CB at 3 months (odds ratio [OR] = 0.32, 95% confidence interval [CI] = 0.16 to 0.61, p<0.001) and 6 months after operation (OR= 0.29, 95% CI = 0.11 to 0.79, p = 0.01). In addition, the technical success rate of HPB groups was higher (OR = 0.13, 95% CI = 0.05 to 0.36, p<0.001). However, no significant difference was observed between HPB and CB groups at 12 months after operation (OR = 0.68, 95% CI = 0.30 to 1.52, p = 0.35). No significant publication bias was observed in the analyses. Conclusion: High-pressure balloon is a potential option for the treatment of AVF stenosis, with a lower 3- and 6-month restenosis rate than CB. However, 12-month patency rate of HPB was not superior to CB. Therefore, further studies should be conducted to investigate the mechanisms of restenosis after angioplasty.

2021 ◽  
Vol 39 ◽  
pp. 163-168
Xiaojun Zhou ◽  
Kangjia Du ◽  
Si Qin ◽  
Dongdi Liu

Food Control ◽  
2021 ◽  
pp. 108749
Wanlu Ma ◽  
Jiaxing Li ◽  
Ayesha Murtaza ◽  
Aamir Iqbal ◽  
Jiao Zhang ◽  

2021 ◽  
Vol 92 (12) ◽  
pp. 124101
Benedikt J. Deschner ◽  
Dmitry E. Doronkin ◽  
Thomas L. Sheppard ◽  
Georg Rabsch ◽  
Jan-Dierk Grunwaldt ◽  

SPE Journal ◽  
2021 ◽  
pp. 1-18
Hu Jia ◽  
Cheng-Cheng Niu ◽  
Chang-Lou Dai

Summary Despite the increasing contribution of renewables to global energy, fossil fuels such as oil and gas still play an important role in energy supply. The development of deep and ultradeep oil and gas reservoirs has become more urgent. Typically, the ultrahigh-temperature and high-pressure (HTHP) environment is a big challenge. Solid-free brine is often used as a weighting component of high-density well completion fluid in the process of well operation, but the large amount of free water can easily cause water blocking damage to the reservoir. Therefore, there is an urgent need to develop a high-density completion fluid system that can be used in HTHP reservoir environments with little free water. In this paper, based on the theory of dispersion, degradation, viscosity extraction, and viscosity stabilization of polymer flexible colloidal particles in brines, an ultrahigh-temperature (180°C)-resistant, solid-free flexible colloidal completion fluid (SFCCF) with variable density and low corrosion was prepared. It breaks through the classical Flory’s water absorption theory. The phosphate brine was selected as the weighting base fluid of SFCCF, and the flexible colloidal particles were saturated with the phosphate brine to improve the density of SFCCF, as well as to reduce free water to lower the potential of water blocking damage. The results show that the dynamic viscosity of SFCCF is adjustable and ranges from 27 to 690 mPa·s, and the density is adjustable in the range of 1 to 1.8 g/cm3. SFCCF is a typical pseudoplastic fluid with shear dilution property, which is the result of the network destruction and the shear deformation of the flexible colloidal particles. The pump rate vs. dynamic viscosity curve is drawn. Under the pump rate of 50 to 800 L/min, the dynamic viscosity of SFCCF (1.2 to 1.7 g/cm3) is less than 40 mPa·s. In addition, SFCCF is viscosity stable for at least 4 days at 180°C and has excellent clay swelling resistance and reservoir fluid compatibility. Finally, SFCCF provides good reservoir protection and rock carrying capabilities and has the advantage of low cost. The successful application of SFCCF in a high-pressure gas well in the East China Sea is summarized, and some recommendations are proposed. The developed SFCCF can significantly reduce water blocking damage in HTHP well operations, providing a new avenue for HTHP well completions.

2021 ◽  
Vol 24 (1) ◽  
pp. 25-32
Mykola Karpenko ◽  
Olegas Prentkovskis ◽  
Šarūnas Šukevičius

Reliability and maintenance analysis of transport machines hydraulic drives, basically focused to power units: pumps, cylinders etc., without taking in to account junction elements. Therefore, this paper proposes a research analysis on high-pressure hoses and junctions during technical maintenance. Comparative analysis of fluid behavior and energy efficiency inside non-repaired and repaired high-pressure hoses is presented in this research. Theoretical and experimental research results for hydraulic processes inside high-pressure hose is based on the numerical simulations using Navier–Stokes equations and experimental measurement of fluid flow pressure inside high-pressure hoses. Research of fluid flow dynamics in the hydraulic system was made with main assumptions: system flow rate in the range from 5 to 100 l/min, diameter of the hoses and repairing fitting are 3/8". The pressure drops, power losses, flow coefficients at non-repaired and after maintenance hose was obtained as a result. Simulation results were verified by running physical experiments to measure the pressure losses.

Liwen Sang ◽  
Meiyong Liao ◽  
Masatomo Sumiya ◽  
Xuelin Yang ◽  
Bo Shen

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