The Accidental Release of Dense Flammable and Toxic Gases from Pressurized Containment - Transition from Pressure Driven to Gravity Driven Phase

1981 ◽  
pp. 463-475
Author(s):  
S. F. Jagger ◽  
G. D. Kaiser
Keyword(s):  
Accidental Release ◽  
Toxic Gases ◽  
Gravity Driven ◽  
Pressure Driven

Effect of Wettability on Oil Recovery by Near-Miscible Gas Injection

1999 ◽  
Vol 2 (06) ◽  
pp. 558-564 ◽  
Author(s):  
Philip L. Wylie ◽  
Kishore K. Mohanty
Keyword(s):  
Mass Transfer ◽  
Oil Recovery ◽  
Water Saturation ◽  
Gas Injection ◽  
Wettability Alteration ◽  
Rock Surface ◽  
Laboratory Studies ◽  
Hydrocarbon Gas ◽  
Gravity Driven ◽  
Pressure Driven

Summary Oil can become bypassed during gas injection as a result of gravitational, viscous, and heterogeneity effects. Mass transfer from the bypassed region to the flowing gas is dependent upon pressure-driven, gravity-driven, and capillary-driven crossflows as well as diffusion and dispersion. The focus of this study is on the influence that wettability has on bypassing and mass transfer. Experimental results reveal comparatively less bypassing occurs in a strongly oil-wet sandstone than in a water-wet sandstone for gravity-dominated, secondary gas floods. Mass transfer under oil-wet conditions is enhanced, as a result of oil-wetting film connectivity, over that of water-wet conditions, where water shielding is significant. Introduction As gas flooding becomes a more viable means of enhanced oil recovery, the ability to quantify and simulate bypassing and mass transfer becomes increasingly important. Bypassing in gas injection processes may occur as a result of gravity override, viscous fingering, or heterogeneities in the reservoir, such as low permeability layers or a fracture-matrix network. Mass-transfer mechanisms, such as pressure-driven, gravity-driven, capillary-driven, and diffusion/dispersion crossflows are studied on the laboratory scale before being scaled up for incorporation into reservoir simulations. The laboratory studies reveal influences that govern the extent that each mechanism contributes to overall mass transfer. The enrichment of the injected gas has been discovered, through simulation and experiment, to play a key role in overall gas flood performance.1–6 Pande2 proposed, using 1D numerical simulation, that secondary and tertiary hydrocarbon gas floods, at or below minimum miscibility pressure or enrichment (MMP or MME), may perform as well as enriched gas floods. Shyeh-Yung1 demonstrated that tertiary gasflood recoveries below MMP do not decrease as severely as predicted by slim-tube tests for CO2 and Shyeh-Yung and Stadler5 and Grigg et al.7 showed that gasflood Sorm increases almost linearly as hydrocarbon gas enrichment decreases. The injection methodology has been shown to affect ultimate oil recovery.7,8 The experiments of Jackson et al.7 demonstrated that the optimum miscible WAG ratio in a water-wet bead pack under tertiary conditions was 0:1 (continuous gas injection) and 1:1 for a miscible flood in an oil-wet bead pack. Laboratory studies have also revealed the influence of mass-transfer zone orientation and water saturation on gasflood oil recovery.9–11 Burger et al.9,10 have found that mass transfer increases with solvent enrichment and that horizontal mass transfer provides the most efficient oil recovery as a result of gravity-driven crossflow. The inverted, or positive gravity orientation, exhibits countercurrent gravity-driven crossflow that inhibits mass transfer somewhat. The vertical, or negative gravity orientation, yielded the lowest recovery, as diffusion was the only significant mass-transfer mechanism for their particular fluid system. Wylie and Mohanty11 have investigated the effect of water saturation on bypassing and mass transfer, concluding that mass transfer is decreased in the presence of water, but that capillary forces become more dominant as enrichment decreases. Less bypassing, due to gravity override, was observed in horizontal gasflood experiments in the presence of water; however, it was conjectured that bypassing was still present as a result of fluid redistribution and water shielding. With the exception of Jackson et al.7 these studies were performed under strongly water-wet or at restored mixed-wet conditions. The extent that media wettability influences gasflood bypassing and the subsequent mass transfer is largely unexplored. Recent research has examined wettability alteration and its influence on waterflood oil recoveries.12,13 Buckley et al.12 concluded that high pH, low ionic strength, monovalent salt solutions typically induce more water-wet conditions on silica surfaces or cores, aged with asphaltic crude oils, while lower pH solutions led to less water wettability. Their results showed optimum waterflood oil recoveries from Clashach cores under mixed-wet conditions with a slightly positive Amott index. Tang and Morrow13 investigated the influences that temperature, salinity, and oil composition have on wettability and waterflood oil recovery from cores aged in crude oil. They discovered wettability to shift toward more water-wet conditions and waterflood oil recovery to increase with a decrease in the salinity of the connate or invading brine. Waterflood oil recoveries also increased as the displacement temperature increased. Basu and Sharma14 provided evidence suggesting that mixed wettability results from the capillarity-induced, destabilization of brine films on the rock surface.

Aerodynamically assisted jetting: a pressure driven approach for processing nanomaterials

2006 ◽  
Vol 1 (1) ◽  
pp. 35 ◽  
Author(s):  
S.N. Jayasinghe ◽  
N. Suter
Keyword(s):  
Pressure Driven

Use of Flexible Materials with a Novel Pressure Driven Equibiaxial Cell Stretching Device for Mechanical Stimulation of Single Mammalian Cells

2003 ◽  
Vol 773 ◽  
Author(s):  
James D. Kubicek ◽  
Stephanie Brelsford ◽  
Philip R. LeDuc
Keyword(s):  
Cell Fate ◽  
Mechanical Stimulation ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Single Cells ◽  
Complex Nature ◽  
Cellular Behavior ◽  
Cell Stretching ◽  
Stimulation Of ◽  
Pressure Driven

AbstractMechanical stimulation of single cells has been shown to affect cellular behavior from the molecular scale to ultimate cell fate including apoptosis and proliferation. In this, the ability to control the spatiotemporal application of force on cells through their extracellular matrix connections is critical to understand the cellular response of mechanotransduction. Here, we develop and utilize a novel pressure-driven equibiaxial cell stretching device (PECS) combined with an elastomeric material to control specifically the mechanical stimulation on single cells. Cells were cultured on silicone membranes coated with molecular matrices and then a uniform pressure was introduced to the opposite surface of the membrane to stretch single cells equibiaxially. This allowed us to apply mechanical deformation to investigate the complex nature of cell shape and structure. These results will enhance our knowledge of cellular and molecular function as well as provide insights into fields including biomechanics, tissue engineering, and drug discovery.

PRESSURE DRIVEN WATER TRANSPORT THROUGH GRAPHENE NANOCHANNEL USING MOLECULAR DYNAMICS SIMULATIONS

2018 ◽  
Author(s):  
Subhendu Rana ◽  
Kishore Kumar Kammara ◽  
Sai Abhishek Peddakotla ◽  
Rakesh Kumar
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Water Transport ◽  
Dynamics Simulations ◽  
Pressure Driven
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