Bridging high pressure rheology and film-forming capacity of polymer-base oil solutions in EHL

Understanding the pressure and shear dependence of viscosity is essential to an understanding of the mechanisms of film forming and friction in concentrated contacts. The blending of different molecular mass polyalphaolefins (PAOs) may permit the formulator to arrive at a desired combination of film thickness and friction. The viscosities of PAO base oils and their blends were measured versus temperature, pressure, and shear stress to 1 GPa in pressure. The Grunberg–Nissan mixing rule, with effective mole fractions, provides an excellent mixing rule for the temperature and pressure-dependent low-shear viscosity. This work provides the first look at a possible mixing rule for the non-Newtonian response of mixtures of base oils.

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Low-Damage Drilling Fluid Technology Used in Jabung Oilfield, Indonesia

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.347-353.1627 ◽

2011 ◽

Vol 347-353 ◽

pp. 1627-1632

Author(s):

Jiao Jiao Geng ◽

Jie Nian Yan ◽

Wen Yi Chen ◽

Chun Yao Peng ◽

Jing Jie Zuo ◽

...

Keyword(s):

High Pressure ◽

Filtration Rate ◽

Drilling Fluid ◽

Formation Damage ◽

Rock Surface ◽

Drilling Fluids ◽

High Permeability ◽

Dynamic Filtration ◽

Film Forming ◽

Sealing Layer

Formation damage is prone to occur during drilling into the formations with medium/high permeability in Jabung Oilfield, Indonesia. To prevent formation damage and enhance productivity of oil wells, a novel low-damage drilling fluid was developed on the basis of the modification of currently used KCl polymer drilling fluid using a special technology. By virtue of the synergistic effect of ideal packing agents and film-forming agents, a sealing layer with high pressure bearing capability can be formed on the rock surface of borehole, so as to prevent drilling fluids from invading into formations effectively. It is shown from the results of numerous experiments that this drilling fluid has excellent rheological properties, very low filtration rates (API filtration rate<4mL and HTHP filtration rate≤12.5mL), good lubricity, and strongly inhibitive character to shale. Also, it exhibits remarkable effectiveness of formation protection indicated by the returned permeability as high as 88.11% and extremely low dynamic filtration rate lower than 4mL.

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High Pressure Treatment for Improving Water Vapour Barrier Properties of Poly(lactic acid)/Ag Nanocomposite Films

Polymers ◽

10.3390/polym10091011 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1011 ◽

Cited By ~ 6

Author(s):

Hai Chi ◽

Jing Xue ◽

Cheng Zhang ◽

Haiyan Chen ◽

Lin Li ◽

...

Keyword(s):

High Pressure ◽

Water Vapour ◽

Barrier Properties ◽

Nanocomposite Films ◽

Poly Lactic Acid ◽

Pressure Treatment ◽

Thermal And Mechanical Properties ◽

High Pressure Treatment ◽

Film Forming ◽

Water Vapour Barrier

Effects of high pressure treatment (0, 200 and 400 MPa) on water vapour barrier, microstructure, thermal, and mechanical properties of poly (lactic acid) (PLA)/Ag nanocomposite films were investigated. The migration behavior of nano-Ag from the nanocomposite films in the presence of 50% (v/v) ethanol as a food simulant was also studied. The water vapour barrier properties increased as pressure was applied to film-forming solutions. High pressure treatment enhanced the mutual effect between PLA and nanoparticles, leading to a more compact network structure in PLA/Ag nanocomposite films. Furthermore, PLA/Ag nanocomposite films treated by high pressure were significantly affected by microstructure, thermal, and mechanical properties when, compared with untreated samples. High pressure treatment at 200 to 400 MPa significantly (p < 0.05) reduced the migration of nano-Ag from the films. Overall, high pressure treatment on film-forming solutions showed potential in improving the functional properties of nanocomposite films, especially in relation to water vapour barrier properties.

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Thermoelastohydrodynamic Behavior of Gas Spiral Groove Face Seals Operating at High Pressure and Speed

Journal of Tribology ◽

10.1115/1.4029358 ◽

2015 ◽

Vol 137 (2) ◽

Cited By ~ 11

Author(s):

Shaoxian Bai ◽

Chunhong Ma ◽

Xudong Peng ◽

Shizhu Wen

Keyword(s):

High Pressure ◽

Fluid Film ◽

Temperature Fields ◽

Thermal Distortion ◽

Face Seal ◽

Spiral Groove ◽

Effect Analysis ◽

Choked Flow ◽

Film Forming ◽

Elastic Distortion

A numerical modeling of thermoelastohydrodynamic gas spiral groove face seal behavior is presented. Temperature fields of the fluid film and the seal rings are computed, as they are the elastic and thermal distortions of the rings. Numerical analysis is carried out on a gas spiral groove face seal taking into account of choked flow effect. Analysis results show that both elastic and thermal distortions induce strong influence on the geometry of the fluid film, forming obvious divergent clearance which leads to significant decrease of minimum equilibrium clearance, exceeding 50% in degree. Thermal distortion may induce the same influence degree as elastic distortion on the minimum equilibrium clearance in high pressure cases, but the rotation speed has no obvious influence on the minimum clearance when both elastic and thermal distortions are considered. The thermal distortion as well as elastic distortion should be concerned in high pressure analysis.

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High-Pressure Density, Viscosity, and Modeling of Mixtures of a Poly(α-olefin) Base Oil Lubricant with Polymeric Additives

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.9b05757 ◽

2020 ◽

Vol 59 (16) ◽

pp. 7926-7942

Author(s):

James S. Dickmann ◽

Katrina Avery ◽

Mark T. Devlin ◽

Erdogan Kiran

Keyword(s):

High Pressure ◽

Base Oil ◽

Polymeric Additives

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Some Observations in High Pressure Rheology of Lubricants

Journal of Lubrication Technology ◽

10.1115/1.3253219 ◽

1982 ◽

Vol 104 (3) ◽

pp. 357-364 ◽

Cited By ~ 70

Author(s):

S. Bair ◽

W. O. Winer

Keyword(s):

Experimental Data ◽

High Pressure ◽

Shear Stress ◽

Shear Modulus ◽

Amorphous Material ◽

Base Oil ◽

Elastic Shear Modulus ◽

Limiting Shear Stress ◽

State History ◽

Elastic Shear

Experimental data are presented on viscosity, elastic shear modulus, and limiting shear stress of 12 liquid lubricants. The effect of adding a polymer V.I. improver to a base oil is discussed. The limiting stress of the amorphous material is shown to be dependent on the state history.

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