Acidizing Low Pressure Gradient Wells Using Carbon Dioxide

1981 ◽  
Author(s):  
Ron Chapman
Keyword(s):  
Carbon Dioxide ◽  
Pressure Gradient ◽  
Low Pressure

Very low-pressure pyrolysis of chloroethane-2,2,2-d3. Kinetics of hydrochloric acid-d elimination and the effect of carbon dioxide inert bath gas

1981 ◽  
Vol 85 (26) ◽  
pp. 4106-4108 ◽  
Author(s):  
Joseph S. Francisco ◽  
Jeffrey I. Steinfeld ◽  
Keith D. King ◽  
Robert G. Gilbert
Keyword(s):  
Carbon Dioxide ◽  
Hydrochloric Acid ◽  
Low Pressure ◽  
Kinetics Of

Pressure and Winds

2000 ◽  
Author(s):  
C. David Whiteman
Keyword(s):  
High Pressure ◽  
Pressure Gradient ◽  
Pressure Difference ◽  
Low Pressure ◽  
Pressure Center ◽  
Vertical Column ◽  
Wind Speeds ◽  
Weather Observations ◽  
Stormy Weather ◽  
Rotation Of The Earth

Atmospheric pressure at a given point in the atmosphere is the weight of a vertical column of air above that level. Differences in pressure from one location to another cause both horizontal motions (winds) and vertical motions (convection and subsidence) in the atmosphere. Vertical motions, whether associated with high and low pressure centers or with other meteorological processes, are the most important motions for producing weather because they determine whether clouds and precipitation form or dissipate. The location of high and low pressure centers is a key feature on weather maps, providing information about wind direction, wind speed, cloud cover, and precipitation. Pressure-driven winds carry air from areas where pressure is high to areas where pressure is low. However, the winds do not blow directly from a high pressure center to a low pressure center. Because of the effects of the rotation of the earth and friction, winds blow clockwise out of a high pressure center and counterclockwise into a low pressure center in the Northern Hemisphere. These wind directions are reversed in the Southern Hemisphere. The strength of the wind is proportional to the pressure difference between the two regions. When the pressure difference or pressure gradient is strong, wind speeds are high; when the pressure gradient is weak, wind speeds are low. As air flows out of a high pressure center, air from higher in the atmosphere sinks to replace it. This subsidence produces warming and the dissipation of clouds and precipitation. As air converges in a low pressure center, it rises and cools. If the air is sufficiently moist, cooling can cause the moisture to condense and form clouds. Further lifting of the air can produce precipitation. Thus, rising pressure readings at a given location indicate the approach of a high pressure center and fair weather, whereas falling pressure readings indicate the approach of a low pressure center and stormy weather. The vertical motions caused by the divergence of air out of a high pressure center or the convergence of air into a low pressure center are generally weak, with air rising or sinking at a rate of several cm per second, and they cannot be measured by routine weather observations.

A Numerical Assessment of Carbon-Dioxide-Rich Two-Phase Flows with Dense Phases in Offshore Production Pipelines

SPE Journal ◽  
2020 ◽  
Vol 25 (02) ◽  
pp. 712-731 ◽  
Author(s):  
Marcelo de A. Pasqualette ◽  
João N. E. Carneiro ◽  
Stein Tore Johansen ◽  
Bjørn Tore Løvfall ◽  
Roberto Fonseca ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Pressure Gradient ◽  
Crude Oil ◽  
Temperature Drop ◽  
Density Ratio ◽  
Flow Simulation ◽  
Phase Identification ◽  
Liquid Density ◽  
Dense Phase ◽  
Offshore Production

Summary One-dimensional numerical simulations of carbon dioxide (CO2)-rich crude-oil flows were performed with a commercial simulator for a typical offshore production pipeline under steady-state scenarios. Mixtures with 20–50 mol% CO2 and gas/oil ratio (GOR) of 300–600 std m3/std m3 were thermodynamically modeled with the predictive Peng-Robinson (PPR78) equation of state (EOS) (Robinson and Peng 1978; Jaubert and Mutelet 2004), and fluid properties were tabulated in pressure/volume/temperature (PVT) lookup tables. Thorough analyses on the separate CO2 and GOR effects on several flow parameters (e.g., temperature drop, pressure gradient, and flow patterns) were performed. The occurrence of the simultaneous flow of liquid and an ambiguous dense phase was quantified and discussed in depth. The properties of those phases [e.g., Joule-Thomson coefficient, viscosity, interfacial tension (IFT), and gas/liquid-density ratio] along the pipeline for several mixtures and operational conditions were addressed as well. It was seen that the dense phase can be a problem for phase-identification criteria, which can affect the flow-simulation results. This was further analyzed in simple cases of horizontal and vertical flows of CO2-rich crude-oil mixtures, under key temperature/pressure conditions. Finally, comparisons were performed between the holdup and pressure-gradient results of those cases, obtained with different liquid/liquid- and gas/liquid-modeling approaches of a hydrodynamic point model of a commercial simulator.

A New Dewaxing Method and its Effect on the Properties of Low-Pressure Injection Molded Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1012-1016
Author(s):  
Yin Wu ◽  
Wen Jie Si ◽  
He Zhuo Miao
Keyword(s):  
Carbon Dioxide ◽  
Injection Molding ◽  
Bending Strength ◽  
Low Pressure ◽  
Supercritical Extraction ◽  
Paraffin Wax ◽  
Organic Additives ◽  
Extraction Condition ◽  
Pressure Injection ◽  
Injection Molded

A new dewaxing method for low-pressure injection molded ceramics is presented. Supercritical extraction with carbon dioxide was used to remove paraffin wax from the ceramic green parts. The composition of organic additives for low-pressure injection molding feedstock and the extraction condition for the green parts were investigated. Moreover, the properties of sintered ceramic samples dewaxed by supercritical carbon dioxide were compared with those by thermal dewaxing. The results show that the new binder system containing 50wt% paraffin wax, 35% bee wax and 15% stearic acid fulfills the requirements of both low-pressure injection molding feedstocks and supercritical dewaxing, where the feedstock has high fluidity, low viscosity and quick solidification. The efficient extraction condition for supercritical dewaxing from the green parts is at 30MPa pressure and 45°C. Under this condition, defect free ceramic green parts can be obtained. Dewaxing methods have significant influence on the properties of sintered parts. The mechanical properties of the sintered sample can be improved by supercritical dewaxing. With this method, the bending strength of sintered samples (σ = 331.6 MPa) is higher than that obtained by thermal treatment (σ = 312.3MPa). The sintered samples dewaxed by supercritical CO2 have shown the property of higher density and less distortion compared to the thermal dewaxing method. Moreover, with supercritical extraction the dewaxing time can be reduced to about one tenth of the time required by thermal dewaxing.

Low-pressure equilibrium data for the prediction of solubility in carbon dioxide

1990 ◽  
Vol 45 (4) ◽  
pp. 795-808 ◽  
Author(s):  
Evelyne Neau ◽  
Paolo Alessi ◽  
Maurizio Fermeglia ◽  
Kikic Ireneo
Keyword(s):  
Carbon Dioxide ◽  
Low Pressure ◽  
Pressure Equilibrium ◽  
Equilibrium Data
Sign in / Sign up

Export Citation Format

Share Document