scholarly journals Prediction of live formation water densities from petroleum reservoirs with pressure-dependent seawater density correlations

DYNA ◽  
2020 ◽  
Vol 87 (213) ◽  
pp. 165-172
Author(s):  
Andrea Paola Sánchez Pérez ◽  
Wilson Antonio Cañas-Marín
Keyword(s):  
Pressure Range ◽  
High Pressures ◽  
Petroleum Reservoirs ◽  
Gas Content ◽  
Formation Water ◽  
Potential Models ◽  
Density Correlations

We studied two density correlations developed for seawater at high pressures as potential models to predict formation water densities from petroleum reservoirs as a function of salinity, pressure, gas content, and temperature. The correlations were tested against experimental densities measured at high pressures for live formation waters sampled under bottomhole conditions from five petroleum reservoirs. As a result, one of these seawater correlations was found to be particularly promising to predict formation water densities for these samples, even out of the pressure range originally reported for such a model.

Responses of cerebral arteries and arterioles to acute hypotension and hypertension

1978 ◽  
Vol 234 (4) ◽  
pp. H371-H383 ◽  
Author(s):  
H. A. Kontos ◽  
E. P. Wei ◽  
R. M. Navari ◽  
J. E. Levasseur ◽  
W. I. Rosenblum ◽  
...  
Keyword(s):  
Pressure Range ◽  
High Pressures ◽  
Cerebral Arteries ◽  
Pial Arteries ◽  
Small Vessels ◽  
Size Dependent ◽  
Arterial Blood ◽  
Vascular Bed ◽  
Acute Hypotension ◽  
Very High

The responses of cerebral precapillary vessels to changes in arterial blood pressure were studied in anesthetized cats equipped with cranial windows for the direct observation of the pial microcirculation of the parietal cortex. Vessel responses were found to be size dependent. Between mean arterial pressures of 110 and 160 mmHg autoregulatory adjustments in caliber, e.g., constriction when the pressure rose and dilation when the pressure decreased, occurred only in vessels larger than 200 micron in diameter. Small arterioles, less than 100 micron in diameter, dilated only at pressures equal to or less than 90 mmHg; below 70 mmHg their dilation exceeded that of the larger vessels. When pressure rose to 170- 200 mmHg, small vessels dilated while the larger vessels remained constricted. At very high pressures (greater than 200 mmHg) forced dilation was frequently irreversible and was accompanied by loss of responsiveness to hypocapnia. Measurement of the pressure differences across various segments of the cerebral vascular bed showed that the larger surface cerebral vessels, extending from the circle of Willis to pial arteries 200 micron in diameter, were primarily responsible for the adjustments in flow over most of the pressure range.

Distensibility of small veins of the dog lung

1992 ◽  
Vol 73 (5) ◽  
pp. 2158-2165 ◽  
Author(s):  
A. al-Tinawi ◽  
A. V. Clough ◽  
D. R. Harder ◽  
J. H. Linehan ◽  
D. A. Rickaby ◽  
...  
Keyword(s):  
Vascular Resistance ◽  
Negative Correlation ◽  
Pressure Range ◽  
High Pressures ◽  
X Ray ◽  
Average Value ◽  
Isolated Lung ◽  
Weak Negative Correlation ◽  
Intravascular Pressure ◽  
Lung Lobes

To determine the distensibility of the intrapulmonary veins (250–2,900 microns diam) of the dog lung, we obtained X-ray angiograms from isolated lung lobes over a vascular pressure range of approximately 0–30 Torr. Over this pressure range the diameter vs. pressure curves tended to flatten out at the high pressures. In the pressure range of 0–19 Torr, we characterized the vessel distensibility by alpha (the ratio of the slope, beta, of the graph of diameter vs. intravascular pressure to the intercept, Do). The average value of alpha was approximately 1.2%/Torr. There was a weak negative correlation (r = -0.32) between alpha and Do. Infusion of enough norepinephrine to produce approximately 50% increase in total lobar vascular resistance produced a decrease in Do and alpha of approximately 33 and 32%, respectively.

Studying Mechanical Properties Of Thin Films Under High Pressures

1990 ◽  
Vol 188 ◽  
Author(s):  
B. C. Cai ◽  
D. Kuhlmann-Wilsdorf ◽  
R. B. Nelson
Keyword(s):  
Work Hardening ◽  
Deformation Behavior ◽  
Recrystallization Texture ◽  
Pressure Range ◽  
High Pressures ◽  
Sample Thickness ◽  
Thickness Effect ◽  
X Ray ◽  
Significant Difference ◽  
Shear Strains

ABSTRACTWork-hardening curves of aluminum foils and of stacks of O.1μm thick 22 ct. gold foils, deformed between rotating Bridgman anvils, have been obtained for pressures up to 1533 MPa and shear strains to 400,000%. No sample thickness effect has been found between 5μm and 3μm, nor any significant difference between homogeneous foils and multi-layer foils, but heat-treatments do affect the results, as apparently does the introduction of 50nm thick sputtered copper layers between stacks of gold foils. Increases of strength with pressure appear to be due to corresponding increases of the Peierls-Nabarro stress. X-ray evidence indicates the reorientation of the foils from an initial (001) recrystallization texture after rolling to the (111) texture that was to be expected. Ordinary deformation behavior is indicated throughout, except for a tendency for slight negative work-hardening in the lower pressure range. At the extreme, assuming homogeneous deformation, the foils thinned to 60nm.

A Study for N2 Coherent Anti-Stokes Raman Spectroscopy Thermometry at High Pressure

1983 ◽  
Vol 37 (6) ◽  
pp. 508-512 ◽  
Author(s):  
Haruhiko Kataoka ◽  
Shiro Maeda ◽  
Chiaki Hirose ◽  
Koichi Kajiyama
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Temperature ◽  
Pressure Range ◽  
High Pressures ◽  
Band Width ◽  
Maximum Height ◽  
Temperature Determination ◽  
Engine Cylinder ◽  
Anti Stokes

N2 coherent anti-Stokes Raman spectroscopy (CARS) thermometry over a pressure range 1 to 50 atm has been studied. The CARS profile at high pressure and high temperature was recorded by using the ignition inside a running engine cylinder. The observed Q-branch profile was theoretically fitted by incorporating the collisional narrowing effect, serving for the temperature determination at various pressures. Because of the narrowing effect, the apparent band width showed little change with pressure above 5 atm in general. It has been suggested that the band width at 1/5 of the maximum height can be a useful measure of temperature, while the usual half-width turns out to be hardly practicable at high pressures.

Tuning of the Acoustical Analysis Model for Hypercompressors Through Strain Gage Pulsation Measurements

2019 ◽  
Author(s):  
Andrea Fusi ◽  
Leonardo Cappelli ◽  
Cosimo Carcasci ◽  
Marco Sacco
Keyword(s):  
Speed Of Sound ◽  
Pressure Range ◽  
High Pressures ◽  
Pressure Sensors ◽  
Compressibility Factor ◽  
Design Stage ◽  
Strain Gages ◽  
Pressure Pulsations ◽  
The Impact ◽  
Very High

Abstract Reciprocating compressor plants are typically exposed to vibrations, resulting from the discontinuity of the flow (pressure pulsations) and from external mechanical loads (compressor motion). To minimize the impact of pressure pulsations on vibration issues, a robust acoustical study is needed in the early design stage. Reliable standards and guidelines concerning vibration and pulsation are available for common applications (up to 350 bar) [1][2]. Within this pressure range it is possible to meet the standards by introducing pulsation suppression devices such as volume bottles or orifices. The Low-Density Polyethylene (LDPE) process requires very high pressures obtained with dedicated machines (Hypercompressors). There are no specific pulsation guidelines for these extreme pressures; in addiction reactive pulsation suppression devices like volume bottles are ineffective due to the high speed of sound in real gas (and related long wavelengths) at such pressures. This paper describes the case history of a plant which exhibited high piping vibration from the first machine start-up. A survey was made to measure vibrations and pressure pulsations by means of strain gages: internal pressure was derived from external deformation through pressure vessel theory. Strain gages were chosen because they can be easily installed without positioning restrictions, while dynamic pressure sensors require pressure taps and must be limited to specific points. Pulsation measurements were compared with an acoustic analysis, showing some discrepancy, especially at relatively high harmonics, mainly due to incorrect evaluation of the thermodynamic properties of high-pressure ethylene. In fact, in the LDPE process pressure range, isentropic exponent kv and compressibility factor Z can reach very high values, consequently affecting the calculation of the speed of sound. A new acoustic modelling was developed to achieve better consistency with the measurements. Pressure-dependent kv and Z were taken into account and a sensitivity analysis of the most relevant valve parameters was performed. Comparing the vibrations and pulsations spectra, once the MNF, compressor manifold arrangement and external loads are known, is fundamental to detect the origin of vibrations and how they are affected by pulsations.

scholarly journals The Virial Effect—Applications for SF6 and CH4 Thermal Plasmas

2019 ◽  
Vol 9 (5) ◽  
pp. 929
Author(s):  
Andriniaina Harry Solo ◽  
Pierre Freton ◽  
Jean-Jacques Gonzalez
Keyword(s):  
High Pressure ◽  
Pressure Range ◽  
High Pressures ◽  
Local Thermodynamic Equilibrium ◽  
Good Alternative ◽  
Mass Action ◽  
Lennard Jones ◽  
Engineering Data ◽  
Large Pressure ◽  
Mass Action Law

A tool based on the mass action law was developed to calculate plasma compositions and thermodynamic properties for pure gases and mixtures, assuming a local thermodynamic equilibrium for pressures of up to 300 bar. The collection of the data that was necessary for tool calculation was automated by another tool that was written using Python, and the formats for the model were adapted directly from the NIST and JANAF websites. In order to calculate the plasma compositions for high pressures, virial correction was introduced. The influences of the parameters that were chosen to calculate the Lennard–Jones (12-6) potential were studied. The results at high pressure show the importance of virial correction for low temperatures and the dependence of the dataset used. Experimental data are necessary to determine a good dataset, and to obtain interaction potential. However, the data available in the literature were not always provided, so they are not well-adapted to a large pressure range. Due to this lack, the formulation provided by L. I. Stiel and G. Thodos (Journal of Chemical and Engineering Data, vol. 7, 1962, p. 234–236) is a good alternative when the considered pressure is not close to the critical point. The results may depend strongly on the system studied: examples using SF6 and CH4 plasma compositions are given at high pressure.

Paper 2: The Velocity of Water Hammer Waves

1965 ◽  
Vol 180 (5) ◽  
pp. 12-20 ◽  
Author(s):  
I. S. Pearsall
Keyword(s):  
High Pressures ◽  
Water Hammer ◽  
Acoustic Velocity ◽  
Gas Content ◽  
Pressure Waves ◽  
Free Gas ◽  
Pumping Stations ◽  
Flow Changes ◽  
Very High ◽  
Good Agreement

Sudden flow changes in a pipeline cause water hammer waves to be transmitted up the pipe. The magnitude of these pressure waves is directly proportioned to the acoustic velocity. The value of the acoustic velocity depends on the bulk modulus or compressibility of the liquid. It is thus affected by pressure, temperature and gas content of the liquid, as well as by the elasticity of the pipe. For water, considerable data are available on the variation of acoustic velocity with temperature and pressure. These are summarized and it is shown that, whereas temperature causes changes of the order of 1 per cent per 5 degC, the variation due to pressure is negligible except at very high pressures. The presence of free gas causes a considerable increase in compressibility, and it is shown that even as little as 1 part of air in 104 parts of water by volume causes a 50 per cent reduction in acoustic velocity. The damping of the pressure waves, which has an overall beneficial effect, is also greatly increased by the presence of free gas, and data are given on these effects. Solids in liquid have a similar but less drastic influence. Experimental results are given of some tests on two sewage pumping stations in which good agreement was obtained between theory and experiment. The elasticity of the pipe also affects the acoustic velocity and a summary is given of the data available for steel, concrete, and rock-lined tunnels, with different types of pipe fixing.

Pressure Dependence of the Thermodynamic Quantities in Phase II of Solid Benzene

2013 ◽  
Vol 32 (5) ◽  
pp. 421-425 ◽  
Author(s):  
H. Yurtseven ◽  
E. Sevinc
Keyword(s):  
Phase Ii ◽  
Pressure Dependence ◽  
Isothermal Compressibility ◽  
Molecular Crystal ◽  
Pressure Range ◽  
High Pressures ◽  
Solid Phase ◽  
Experimental Measurements ◽  
Thermodynamic Quantities ◽  
Volume Data

AbstractThe thermodynamic quantities such as the thermal expansion (αp), isothermal compressibility (KT) and the specific heat (CP − CV), are predicted at various pressures up to 26 GPa (T = 540 K) in the solid phase II of benzene using volume data from the literature. The Pippard relations are examined using the pressure dependence of αp, KT and CP − CV and the value of the slope dP/dT is deduced for the solid phase II of benzene. The thermodynamic quantities studied here decrease with increasing pressure, as expected, which can be compared with the experimental measurements for the solid phase II of benzene. We find that the Pippard relations are validated within the pressure range considered, in particular, at high pressures for the solid phase II of this molecular crystal.

Computational Mechanics of the Sclera and Optic Nerve Head (ONH): Effects of ONH Size and Pressure Range

2008 ◽  
Author(s):  
Lewis Waldman ◽  
Crystal Cunanan ◽  
Sanjay Asrani ◽  
Roy Kerckhoffs ◽  
Andrew McCulloch
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Material Properties ◽  
Pressure Range ◽  
High Pressures ◽  
Strain Differences ◽  
Temporal Variations ◽  
Nonlinear Material ◽  
Stress And Strain ◽  
Strain Components

Computational modeling was performed to study how loss of compliance of the eye and abnormally high pressures result in changes in stresses and strains that may impact the optic nerve in diseases such as glaucoma. Hemispherical finite element models of the eye were created in which scleral thickness varied from the equatorial region to the optic nerve head (ONH). Nonhomogeneous material properties were used to model the ONH as a continuous region softer than the adjacent sclera. The ONH and an adjacent buffer zone in the sclera were modeled with enough detail that the size of the ONH could be changed to account for variations observed in humans. The model was provided with appropriate dimensions typical of patients and nonlinear material properties with decreased compliance. Models with different ONH sizes were inflated in small steps to 55 mmHg (7.33 kPa), providing deformed configurations at intermediate pressures of 15, 30 and 45 mmHg, respectively. Color-coded maps of stress and strain components were rendered directly on deformed configurations of the eye model; and animations were produced that show both spatial and temporal variations of stresses and strains as internal pressure increases. Three-dimensional stresses and accompanying finite strains were similar for ONH sizes ranging form 1.5 to 2.5 mm in diameter. Stress and strain differences were estimated as pressure was increased from 15 to 25 mmHg, 30 to 40 mmHg, and 45 to 55 mmHg. Substantial changes occurred in stress and strain differences as the pressure range was varied with large changes occurring in the lowest pressure range for strain components and moderate increases in stress differences as pressures increase.

THE OXIDATION OF METHANE AT HIGH PRESSURES: II. EXPERIMENTS WITH VARIOUS MIXTURES OF VIKING NATURAL GAS AND AIR

1937 ◽  
Vol 15b (10) ◽  
pp. 401-413 ◽  
Author(s):  
E. H. Boomer ◽  
Victor Thomas
Keyword(s):  
Natural Gas ◽  
Pressure Range ◽  
High Pressures ◽  
Space Velocity ◽  
Principal Product ◽  
Temperature Range ◽  
Oxidation Of Methane ◽  
Mixture Pressure

Mixtures of a natural gas, substantially methane, and air in various proportions were passed over catalysts, and the effects of the variables, composition of mixture, pressure, temperature, and space velocity, were determined. Similar experiments were made with mixtures of methane and air. Mixtures containing from less than 3% to more than 13% of oxygen as air were used. The temperature range was 350° to 500 °C. and the pressure range 140 to 230 atm. Methanol was the principal product, and yields as high as 74% on the basis of carbon oxidized were obtained. Copper was the principal catalyst used. Traces of sulphur poisoned the catalyst very effectively.

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