Parameter-Free Inter-view Depth Propagation for Mobile Free-View Video

2014 ◽  
pp. 161-169
Author(s):  
Binbin Xiong ◽  
Weimin Wu ◽  
Haojie Li ◽  
Hongtao Yu ◽  
Hanzi Mao
Keyword(s):  
Depth Propagation

Chemical EOR in Low Permeability Sandstone Reservoirs: Impact of Clay Content on the Transport of Polymer and Surfactant

2021 ◽  
Author(s):  
Imane Guetni ◽  
Claire Marlière ◽  
David Rousseau
Keyword(s):  
Porous Media ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Clay Content ◽  
Low Permeability ◽  
Depth Propagation ◽  
The Impact ◽  
Polymer Retention ◽  
Injection Strategies

Abstract Application of chemical enhanced oil recovery (C-EOR) processes to low-permeability sandstone reservoirs (in the 10-100 mD range) can be very challenging as strong retention and difficult in-depth propagation of polymer and surfactant can occur. Transport properties of C-EOR chemicals are particularly related to porous media mineralogy (clay content). The present experimental study aimed at identifying base mechanisms and providing general recommendations to design economically viable C-EOR injection strategies in low permeability clayey reservoirs. Polymer and surfactant injection corefloods were conducted using granular packs (quartz and clay mixtures) with similar petrophysical characteristics (permeability 70-130 mD) but having various mineralogical compositions (pure quartz sand, sand with 8 wt-% kaolinite and sand with 8 wt-% smectite). The granular packs were carefully characterized in terms of structure (SEM) and specific surface area (BET). The main observables from the coreflood tests were the resistance and residual resistance factors generated during the chemical injections, the irreversible polymer retention and the surfactant retention in various injection scenarios (polymer alone, surfactant alone, polymer and surfactant). A first, the impact of the clay contents on the retention of polymer and surfactant considered independently was examined. Coreflood results have shown that retention per unit mass of rock strongly increased in presence of both kaolinite and smectite, but not in the same way for both chemicals. For polymer, retention was about twice higher with kaolinite than with smectite, despite the fact that the measured specific surface area of the kaolinite was about 5 times less than that of the smectite. Conversely, for surfactant, retention was much higher with smectite than with kaolinite. Secondly, the impact of the presence of surfactant on the polymer in-depth propagation and retention was investigated in pure quartz and kaolinite-bearing porous media. In both mineralogies, the resistance factor quickly stabilized when polymer was injected alone whereas injection of larger solution volumes was required to reach stabilization when surfactant was present. In pure quartz, polymer retention was shown, surprisingly, to be one order of magnitude higher in presence of surfactant whereas with kaolinite, surfactant did not impact polymer retention. The results can be interpreted by considering adsorption-governed retention. The mechanistic pictures being that (a) large polymer macromolecules are not able to penetrate the porosity of smectite aggregates, whereas surfactant molecules can, and (b) that surfactant and polymer mixed adsorbed layers can be formed on surfaces with limited affinity for polymer. Overall, this study shows that C-EOR can be applied in low permeability reservoirs but that successful injection strategies will strongly depend on mineralogy.

Depth propagation across an illusory surface

2007 ◽  
Vol 24 (4) ◽  
pp. 905 ◽  
Author(s):  
Shigeaki Nishina ◽  
Arash Yazdanbakhsh ◽  
Takeo Watanabe ◽  
Mitsuo Kawato
Keyword(s):  
Depth Propagation

Towards naturalistic depth propagation

IVMSP 2013 ◽  
2013 ◽  
Author(s):  
Weicheng Huang ◽  
Xun Cao ◽  
Ke Lu ◽  
Qionghai Dai ◽  
Alan Bovik
Keyword(s):  
Depth Propagation

Sensitivity Study of Dynamics Variability for Mild-carbon Steel Structures Affected by Corrosion

2019 ◽  
Vol 13 (1) ◽  
pp. 251-268 ◽  
Author(s):  
Gianmaria Di Lorenzo ◽  
Raffaele Landolfo
Keyword(s):  
Limit State ◽  
Steel Structures ◽  
Sensitivity Study ◽  
Structural Elements ◽  
Corrosion Depth ◽  
Wind Action ◽  
Structure Reliability ◽  
Corrosion Propagation ◽  
Design Loads ◽  
Depth Propagation

Background: Corrosion propagation mainly occurs due to environmental conditions and to the absence of adequate maintenance. The corrosion propagation affects the structural performances of slender and thin structures, in particular in the case of structure very sensitive to the wind action and its dynamical phenomena, because commonly they are designed with a precise optimization of the stiffness/mass ratio. The static and dynamic wind action represent an immediate safety hazard in the case of structural stiffness and mass reduction due to the corrosion depth. Objective: This paper discusses the dynamics behavior variability due to the corrosion depth propagation for two significant examples of slender and thin structure (i.e. tower and truss roof). Methods: The structures assumed as case of study are made of mild carbon. The corrosion depth variability was estimated based on literature references. The structural natural frequencies and modal shapes are assumed as significant magnitudes to discuss the effect of the corrosion on the structural elements. Results: Results have shown that the corrosion depth gives a significant reduction of frequencies and modification of modal shapes. Conclusion: Results have shown that the corrosion depth affect the structural behavior long before a structural collapse. It suggests that a monitoring must be done to estimate the structure reliability for the Serviceability limit state under Characteristic design loads.

All-in-focus with directional-max-gradient flow and labeled iterative depth propagation

2018 ◽  
Vol 77 ◽  
pp. 173-187 ◽  
Author(s):  
Guijin Wang ◽  
Wentao Li ◽  
Xuanwu Yin ◽  
Huazhong Yang
Keyword(s):  
Gradient Flow ◽  
Depth Propagation
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