Preparation and Performance of Wax Emulsionusing in Drilling Fluid

2014 ◽  
Vol 552 ◽  
pp. 286-290
Author(s):  
Pei Zhi Yu

An O/W type paraffin wax emulsions was prepared using Tweenand Span emulsifiers, and liquid paraffin. The influences of temperature, HLB and surfactants concentration in particle size of paraffin wax emulsions were studied, as were the stability of paraffin wax emulsions. The application performances in drilling fluid of paraffin wax emulsions were researched with respect to artificial core line swelling and shale recovery. Results showed that the best conditions of preparation of emulsified wax: surfactants concentration was 5%, temperature was 50°Cand HLB was 10.1-10.5. It was found that paraffin wax emulsions possess strong inhibition ability for hydration, swelling and dispersing of clay and shale. The inhibition ability of paraffin wax emulsions enhanced with KCl.


2017 ◽  
Vol 744 ◽  
pp. 498-505 ◽  
Author(s):  
Fei Liu ◽  
Yan Ling Wang

The reversible invert emulsion drilling fluids can achieve performance of oil based drilling fluid and solve the disadvantages associated by the oil based drilling fluid. This reversible invert emulsion drilling fluid can also focus the advantages of both oil based and water based drilling fluids. The surfactant emulsifier is the currently reported emulsifier used in the reversible invert emulsion. The stability of the reversible invert emulsion drilling fluid is very poor that can be known from the low emulsion breaking voltage. The dosage of the surfactant emulsifier is so much that it can increase the drilling cost and environmental pollution. In this paper, organic amine surfactant-modified nanoparticles are prepared and the modified nanoparticle which can be used to stabilize the reversible invert emulsion drilling fluid is chosen. The stability of the reversible invert emulsion drilling fluid stabilized by modified nanoparticles (emulsion breaking voltage>1100V) is better than the reversible invert emulsion drilling fluid stabilized by surfactant (450V<emulsion breaking voltage<600V). The dosage of the organic amine surfactant-modified nanoparticle emulsifier (2.4 wt.%) is less than the dosage of the surfactant emulsifier (4 wt.%), hence, reducing the drilling cost and environmental threat. The reversible invert emulsion drilling fluid stabilized by modified nanoparticles perform similar to the reversible invert emulsion drilling fluid stabilized by surfactant in the aspect of oiliness cuttings treatment. The reversible invert emulsion drilling fluid stabilized by modified nanoparticles also perform well in the aspect of oiliness cuttings treatment.



2021 ◽  
Vol 9 (3) ◽  
pp. 290
Author(s):  
Yukai Li ◽  
Yuli Hu ◽  
Youguang Guo ◽  
Baowei Song ◽  
Zhaoyong Mao

Permanent magnet couplings can convert a dynamic seal into a static seal, thereby greatly improving the stability of the underwater propulsion unit. In order to make full use of the tail space and improve the transmitted torque capability, a conical Halbach permanent magnet coupling (C-HPMC) is proposed in this paper. The C-HPMC combines multiple cylindrical HPMCs with different sizes into an approximately conical structure. Compared with the conical permanent magnet couplings in our previous work, the novel C-HPMC has better torque performance and is easy to process. The analytical calculation method of transmitted torque of C-HPMC is proposed on the basis of torque calculation of the three common types of HPMCs. The accuracy of the torque calculation of the three HPMCs is verified, and the torque performance of the three HPMCSs of different sizes is compared and discussed. The “optimal type selection” method is proposed and applied in the design of C-HPMC. Finally, on the basis of torque analysis calculation and axial force calculation, a complete flowchart of the design and performance analysis of C-HPMC is described.



Author(s):  
Yiqi Xu

This paper studies the attitude-tracking control problem of spacecraft considering on-orbit refuelling. A time-varying inertia model is developed for spacecraft on-orbit refuelling, which actually includes two processes: fuel in the transfer pipe and fuel in the tank. Based upon the inertia model, an adaptive attitude-tracking controller is derived to guarantee the stability of the resulted closed-loop system, as well as asymptotic convergence of the attitude-tracking errors, despite performing refuelling operations. Finally, numerical simulations illustrate the effectiveness and performance of the proposed control scheme.



1989 ◽  
Vol 155 ◽  
Author(s):  
Wan V. Shih ◽  
Wei-Heng Shih ◽  
Jun Liu ◽  
Ilhan A. Aksay

The stability of a colloidal suspension plays an important role in colloidal processing of materials. The stability of the colloidal fluid phase is especially vital in achieving high green densities. By colloidal fluid phase, we refer to a phase in which colloidal particles are well separated and free to move about by Brownian motion, By controlling parameters such as pH, salt concentration, and surfactants, one can achieve high packing (green) densities in the repulsive regime where the suspension is well dispersed as a colloidal fluid, and low green densities in the attractive regime where the suspensions are flocculated [1,2]. While there is increasing interest in using bimodal suspensions to improve green densities, neither the stability of a binary suspension as a colloidal fluid nor the stability effects on the green densities have been studied in depth as yet. Traditionally, the effect of using bimodal-particle-size distribution has only been considered in terms of geometrical packing developed by Furnas and others [3,4]. This model is a simple packing concept and is used and useful for hard sphere-like repulsive interparticle interactions. With the advances in powder technology, smaller and smaller particles are available for ceramic processing. Thus, the traditional consideration of geometrial packing for the green densities of bimodal suspensions may not be enough. The interaction between particles must be taken into account.



2011 ◽  
Vol 368-373 ◽  
pp. 2411-2416
Author(s):  
Jian Ping Han ◽  
Hai Peng Liu

Temporary or permanent supports are necessary in underground construction for maintaining the stability and limiting the damage of surrounding rock. Due to the uncertainty of geological structure, the specificity of the underground environment as well as other factors, the quality and performance of supporting structure are often difficult to satisfy the design requirements, which not only seriously affects the normal construction and operation of mines but also has the potential threat to the safety of underground production. In order to investigate the influence of the unfavorable geologic environment on supporting concrete and evaluate the real performance of roadway supports of a mine, 17 typical projects were chosen and the strength of supporting concrete was detected by nondestructive drilling core method. The result shows that the strength is widely less than the design value. Furthermore, 4 projects of them were investigated by the ground penetrating radar (GPR) in order to evaluate the feasibility of GPR in the performance investigation of the roadway supports of a mine. The results indicate that ground penetrating radar is capable of measuring the thickness of the support, the distribution of rebars and the defects of the surrounding rock.



2021 ◽  
Vol 61 ◽  
pp. 155-162
Author(s):  
Kyuhwan Hyun ◽  
Joonyoung Lee ◽  
Suhyeon Kang ◽  
Yongchai Kwon


2013 ◽  
Vol 136 (6) ◽  
Author(s):  
Subenuka Sivagnanasundaram ◽  
Stephen Spence ◽  
Juliana Early

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes were designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor was highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and noncavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.



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