Joint Effect of Poly(ethyhlene-co-1-octene) Chain Length and 1-Octene Fraction on High-Temperature Thermal Gradient Interaction Chromatography

2016 ◽  
Vol 218 (1) ◽  
pp. 1600332 ◽  
Author(s):  
Abdulaal Z. Al-Khazaal ◽  
João B. P. Soares
Keyword(s):  
High Temperature ◽  
Chain Length ◽  
Thermal Gradient ◽  
Joint Effect

High temperature studies of Urania in a thermal gradient

1969 ◽  
Vol 30 (1-2) ◽  
pp. 50-56 ◽  
Author(s):  
B.E. Fryxell ◽  
E.A. Aitken
Keyword(s):  
High Temperature ◽  
Thermal Gradient

Unsaturation Characterization of Polyolefins by NMR and Thermal Gradient NMR (TGNMR) with a High Temperature Cryoprobe

2012 ◽  
Vol 312 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Zhe Zhou ◽  
Rongjuan Cong ◽  
Yiyong He ◽  
Manjiri Paradkar ◽  
Mehmet Demirors ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Gradient

A Novel Gemini Cationic Viscoelastic Surfactant-Based Fluid for High Temperature Well Stimulation Applications

2021 ◽  
Author(s):  
Dawn Friesen ◽  
Brian Seymour ◽  
Aaron Sanders
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Chain Length ◽  
Surfactant Concentration ◽  
Gemini Surfactant ◽  
Alkyl Chain ◽  
Friction Reduction ◽  
Fluid Viscosity ◽  
Viscoelastic Surfactant ◽  
The Impact

Abstract Viscoelastic surfactant (VES)-based fracturing fluids can reduce the risk of formation damage when compared with conventional polymer-based fracturing systems. However, many VES systems lose viscoelasticity rapidly under high-temperature conditions, leading to high fluid leakoff and problems in proppant placement. A gemini cationic VES-based system offering thermal stability above 250°F and its efficiency in friction reduction is presented in this paper. Rheology measurements were conducted on viscoelastic cationic gemini surfactant fluids as a function of temperature (70 – 300°F) and surfactant concentration. The length of surfactant alkyl chain was varied to investigate the impact of surfactant chain length on VES fluid viscosity at elevated temperatures. The effect of flow rate on friction reduction capability of the surfactant fluid was measured on a friction flow loop. Foam rheology measurements were conducted to evaluate the VES fluid's ability to maintain high temperature viscosity with reduced surfactant concentration. A gemini cationic surfactant was used to prepare a viscoelastic surfactant system that could maintain viscosity over 50 cP at a shear rate of 100 s−1up to at least 250°F. With this system, viscoelastic gel viscosity was maintained without degradation for over 18 hours at 250°F, and the fluid showed rapid shear recovery throughout. Decreasing the average alkyl chain length on the surfactant reduced the maximum working temperature of the resulting viscoelastic gel and showed the critical influence of surfactant structure on the resulting fluid performance. The presence of elongated, worm-like micelles in the fluid provided polymer-like friction reduction even at low surfactant concentrations, with friction reduction of over 70% observed during pumping (relative to fresh water) up to a critical Reynolds number. Energized fluids could also be formulated with the gemini surfactant to give foam fluids suitable for hydraulic fracturing or wellbore cleanouts. The resulting viscoelastic surfactant foams had viscosities over 50 cP up to at least 300°F with both nitrogen and carbon dioxide as the gas phase. The information presented in this paper is important for various field applications where thermal stability of the treatment fluid is essential. This will hopefully expand the use of VES-based systems as an alternative to conventional polymer systems in oilfield applications where a less damaging viscosified fluid system is required.

Metamorphism of the MacLean Lake and Central Metavolcanic belts, La Ronge domain, Trans-Hudson Orogen: pressure-temperature variations and tectonic implications

1998 ◽  
Vol 35 (8) ◽  
pp. 905-922 ◽  
Author(s):  
Haiming Yang ◽  
Kurt Kyser ◽  
Kevin Ansdell
Keyword(s):  
High Temperature ◽  
Thermal Gradient ◽  
Amphibolite Facies ◽  
Tectonic Zone ◽  
Thrust Sheet ◽  
Temperature Variations ◽  
High Thermal Gradient ◽  
Tectonic Implications ◽  
Peak Metamorphism ◽  
Peak Pressures

Metamorphic assemblages differ between the metasedimentary MacLean Lake belt and the adjacent Central Metavolcanic belt in the La Ronge domain, Trans-Hudson Orogen. The former consists of meta-arkoses, psammitic gneisses, metaconglomerates, and calc-silicate gneisses of upper amphibolite facies (600-740°C, 440-660 MPa) with local migmatization, whereas the latter is comprised mainly of metavolcanic and plutonic rocks, with minor metasedimentary schists of greenschist to lower amphibolite facies (480-630°C, 520-560 MPa). Petrographic evidence indicates that peak metamorphic conditions were reached towards the end of D1 deformation during which the Central Metavolcanic belt was thrust onto the MacLean Lake belt along the McLennan Lake tectonic zone, which separates the two belts. Peak metamorphic assemblages did not undergo retrograde alteration during D2 deformation, indicating that high temperature was maintained during D2 deformation. Differences in pressure (P) and temperature (T) between the northeastern and southwestern parts of the Central Metavolcanic belt may have resulted from tilting along strike after peak metamorphism. Peak temperatures increase gradually from the Central Metavolcanic belt to MacLean Lake belt across the McLennan Lake tectonic zone. Peak pressures in the two belts are similar, implying that the Central Metavolcanic belt thrust sheet was probably thin. The P-T data for the MacLean Lake belt indicate a relatively high thermal gradient (40-50°C/km), similar to that in the metasedimentary Kisseynew domain in the orogen.

Bacillus thermoamylovorans-Related Strain Isolated from High Temperature Sites as Potential Producers of Medium-Chain-Length Polyhydroxyalkanoate (mcl-PHA)

2020 ◽  
Vol 77 (10) ◽  
pp. 3044-3056
Author(s):  
Aophat Choonut ◽  
Poonsuk Prasertsan ◽  
Sappasith Klomklao ◽  
Kanokphorn Sangkharak
Keyword(s):  
High Temperature ◽  
Chain Length ◽  
Related Strain ◽  
Medium Chain ◽  
Medium Chain Length

Synchrotron XRD Measurements Mapping Internal Strains of Thermal Barrier Coatings During Thermal Gradient Mechanical Fatigue Loading

2014 ◽  
Author(s):  
Kevin Knipe ◽  
Albert C. Manero ◽  
Stephen Sofronsky ◽  
John Okasinski ◽  
Jonathan Almer ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Mechanical Loading ◽  
Bond Coat ◽  
Thermal Gradient ◽  
Room Temperature ◽  
Material Behavior ◽  
Thermal Barrier ◽  
X Rays ◽  
Barrier Coatings

An understanding of the high temperature mechanics experienced in Thermal Barrier Coatings (TBC) during cycling conditions would be highly beneficial to extending the lifespan of the coatings. This study will present results obtained using synchrotron x-rays to measure depth resolved strains in the various layers of TBCs under thermal mechanical loading and a superposed thermal gradient. Tubular specimens, coated with Yttria Stabilized Zirconia (YSZ) and an aluminum containing nickel alloy as a bond coat both through Electron Beam - Physical Vapor Deposition (EBPVD), were subjected to external heating and controlled internal cooling generating a thermal gradient across the specimen’s wall. Temperatures at the external surface were in excess of 1000 °C. Throughout high temperature testing, 2-D high-resolution XRD strain measurements are taken at various locations through the entire depth of the coating layers. Across the YSZ a strain gradient was observed showing higher compressive strain at the interface to the bond coat than towards the surface. This behavior can be attributed to the specific microstructure of the EB-PVD-coating, which reveals higher porosity at the outer surface than at the interface to the bond coat, resulting in a lower in plane modulus near the surface. This location at the interface displays the most significant variation due to applied load at room temperature with this effect diminishing at elevated uniform temperatures. During thermal cycling with a thermal gradient and mechanical loading, the bond coat strain moves from a highly tensile state at room temperature to an initially compressive state at high temperature before relaxing to zero during the high temperature hold. The results of these experiments give insight into previously unseen material behavior at high temperature which can be used to develop an increased understanding of various failure modes and their causes.

Sign in / Sign up

Export Citation Format

Share Document