Multiple Foam States and Long-Distance Foam Propagation in EOR Displacements

2012 ◽  
Author(s):  
Elham Ashoori ◽  
Dan Marchesin ◽  
William Richard Rossen
Keyword(s):  
Long Distance ◽  
Foam Propagation

Multiple Foam States and Long-Distance Foam Propagation in Porous Media

SPE Journal ◽  
2012 ◽  
Vol 17 (04) ◽  
pp. 1231-1245 ◽  
Author(s):  
E.. Ashoori ◽  
D.. Marchesin ◽  
W.R.. R. Rossen
Keyword(s):  
Oil Recovery ◽  
Water Saturation ◽  
High Water ◽  
Superficial Velocity ◽  
Injection Well ◽  
Long Distance ◽  
Riemann Solutions ◽  
Lower Velocity ◽  
Foam Propagation ◽  
Strong Foam

Summary Creation of low-mobility foam for enhanced oil recovery (EOR) is triggered by an increase in superficial velocity; thereafter, injection rate can be reduced to lower values, and strong foam remains at velocities at which weak foam was previously observed. Here, we consider whether strong foam created near an injection well can propagate to large distances from the well where superficial velocity is much smaller. We study strong-foam propagation with finite-difference simulations and Riemann solutions, applying a population-balance foam model that represents the multiple steady states of foam. Our simulations show that strong foam cannot displace directly the initial high-water-saturation bank initially in the reservoir at low superficial velocities; it pushes a weak-foam state with lower velocity that in turn displaces the bank ahead. Our traveling-wave solutions show that strong foam propagates more slowly as superficial velocity decreases and stops propagating at yet lower superficial velocities, in agreement with the experiment. Failure of propagation occurs at superficial velocities greater than that at which the strong-foam state disappears; it raises concerns for long-distance propagation of strong foam created near the injection well. In the context of the model, it is not extraordinary destruction of foam at the front that slows the propagation of strong foam, but failure of foam (re-)generation at the front. Our model also represents for the first time a process where strong foam is created near the exit of a core and then propagates upstream, as seen in some experiments.

Foam Propagation at Low Superficial Velocity: Implications for Long-Distance Foam Propagation

SPE Journal ◽  
2020 ◽  
Vol 25 (06) ◽  
pp. 3457-3471
Author(s):  
Guanqun Yu ◽  
Sebastien Vincent-Bonnieu ◽  
William R. Rossen
Keyword(s):  
Superficial Velocity ◽  
Long Distance ◽  
Foam Propagation

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

Popliteal entrapment syndrome and age

VASA ◽  
2012 ◽  
Vol 41 (4) ◽  
pp. 262-268 ◽  
Author(s):  
Schweizer ◽  
Hügli ◽  
Koella ◽  
Jeanneret
Keyword(s):  
Risk Factors ◽  
Leg Pain ◽  
Walking Distance ◽  
Therapeutic Approaches ◽  
Long Distance ◽  
Entrapment Syndrome ◽  
Long Distance Running ◽  
Popliteal Entrapment ◽  
Popliteal Entrapment Syndrome ◽  
Atherosclerotic Risk Factors

On the occasion of diagnosing a popliteal entrapment syndrome in a 59-year old man with no cardiovascular risk factors, who developed acute ischemic leg pain during long distance running, we give an overview on this entity with emphasis on patients’age. The different types of the popliteal artery compression syndrome are summarized. The diagnostic and therapeutic approaches are discussed. The most important clinical sign of a popliteal entrapment syndrome is the lack of atherosclerotic risk factors in patients with limited walking distance. Not only in young athletes but also in patients more than 50 years old the popliteal entrapment syndrome has to be taken into account.

Attachment Styles, Physical Proximity, and Relational Satisfaction

2014 ◽  
Vol 4 (2) ◽  
pp. 106-112
Author(s):  
Anita Shrivastava ◽  
Andrea Burianova
Keyword(s):  
Attachment Styles ◽  
Romantic Relationship ◽  
Distinct Type ◽  
Relational Satisfaction ◽  
Long Distance ◽  
Avoidant Attachment ◽  
Geographic Separation ◽  
Relationship Of ◽  
Attachment Dimensions

This study aimed to explore the relationships between attachment styles, proximity, and relational satisfaction. This was achieved by assessing a distinct type of long distance romantic relationship of flying crews, compared with proximal (non-flying crew) romantic relationships. The responses of 139 expatriate professionals revealed significant associations between proximity and anxious and avoidant attachment dimensions. The role of the avoidant dimension in comparison with that of the anxious dimension was found to be a significant predictor of relational satisfaction. This study contributes significantly toward addressing the role of proximity and attachment in relational satisfaction in a new context of geographic separation.

Long-distance plant traffic

Nature ◽  
2001 ◽  
Author(s):  
Helen Pearson
Keyword(s):  
Long Distance
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