Acoustic Velocity Measurements and Interpretation for Challenging Fluid Systems

SPE Journal ◽  
2016 ◽  
Vol 22 (01) ◽  
pp. 103-119 ◽  
Author(s):  
Edward Lewis ◽  
Birol Dindoruk
Keyword(s):  
Heat Capacity ◽  
Isothermal Compressibility ◽  
Measured Data ◽  
Acoustic Velocity ◽  
Hydrocarbon Mixture ◽  
Data Sets ◽  
Velocity Measurements ◽  
Numerical Work ◽  
Reliable Determination ◽  
Quality Control Tool

Summary In terms of experimentation, acoustic velocity can be measured with a high degree of accuracy. Several thermodynamic properties related to acoustic velocity such as density, isothermal compressibility, and heat capacity can be extracted from measured data. In this study, technical improvements are implemented in an effort to develop a technique for fast and reliable determination of fluid properties on the basis of acoustic velocity measurements over an expanded range of pressures. The potential use of this device as a quality-control tool in typical pressure/volume/temperature (PVT) measurements is demonstrated. Baseline measurements matched to published literature verify the suitability of the device. Results of tests on three recombined oil samples containing dissolved gas, with prescribed gas/oil ratios (GORs), and one bitumen sample are presented. A sharp change in the acoustic velocity trend near the gas/liquid-saturation point is evidence of gas evolution during depressurization. Strong attenuation complicates measurement of acoustic velocity on the heavy fluids used in this study. Blending bitumen with a midrange-molecular-weight hydrocarbon mixture enables estimation of the undiluted-fluid acoustic velocity by extrapolation. By use of the measured acoustic velocity data available, a methodology is developed to estimate and quality check measured isothermal compressibility (κT) values. This is especially important for low-compressibility systems. Heat-capacity data for simple alkanes (CH4 to n-C10) and toluene helps to define a reasonable range of heat-capacity ratio (γ) expected for typical reservoir fluids. For the typical values of acoustic velocity encountered in the pressure and temperature range of interest, the isothermal compressibility can be calculated and/or quality checked by use of estimated values of γ. In addition, by use of various data sets and by performing graphical error analysis, we have shown the reasons that the methodology works. Available data for n-decane and n-hexadecane along with measured data for a live oil and numerical work on calibrated data sets in this study are used to develop the methodology.

scholarly journals Estimating a Stoichiometric Solid’s Gibbs Free Energy Model by Means of a Constrained Evolutionary Strategy

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 471
Author(s):  
Constantino Grau Turuelo ◽  
Sebastian Pinnau ◽  
Cornelia Breitkopf
Keyword(s):  
Heat Capacity ◽  
Free Energy ◽  
Evolutionary Strategy ◽  
Data Sets ◽  
Automatic Data ◽  
Physical Constraints ◽  
Stoichiometric Model ◽  
Covariance Matrix Adaptation ◽  
Dsc Measurements ◽  
Capacity Data

Modeling of thermodynamic properties, like heat capacities for stoichiometric solids, includes the treatment of different sources of data which may be inconsistent and diverse. In this work, an approach based on the covariance matrix adaptation evolution strategy (CMA-ES) is proposed and described as an alternative method for data treatment and fitting with the support of data source dependent weight factors and physical constraints. This is applied to a Gibb’s Free Energy stoichiometric model for different magnesium sulfate hydrates by means of the NASA9 polynomial. Its behavior is proved by: (i) The comparison of the model to other standard methods for different heat capacity data, yielding a more plausible curve at high temperature ranges; (ii) the comparison of the fitted heat capacity values of MgSO4·7H2O against DSC measurements, resulting in a mean relative error of a 0.7% and a normalized root mean square deviation of 1.1%; and (iii) comparing the Van’t Hoff and proposed Stoichiometric model vapor-solid equilibrium curves to different literature data for MgSO4·7H2O, MgSO4·6H2O, and MgSO4·1H2O, resulting in similar equilibrium values, especially for MgSO4·7H2O and MgSO4·6H2O. The results show good agreement with the employed data and confirm this method as a viable alternative for fitting complex physically constrained data sets, while being a potential approach for automatic data fitting of substance data.

Validating and Updating Finite Element Models Using Experimental Measurements of Dynamics

1990 ◽  
Vol 204 (1) ◽  
pp. 45-50
Author(s):  
C F McCulloch ◽  
P Vanhonacker ◽  
E Dascotte
Keyword(s):  
Finite Element ◽  
Structural Dynamics ◽  
Model Updating ◽  
Measured Data ◽  
Physical Parameters ◽  
Experimental Measurements ◽  
Finite Element Models ◽  
Data Sets ◽  
Modal Data ◽  
Modelling Assumptions

A method is proposed for updating finite element models of structural dynamics using the results of experimental modal analysis, based on the sensitivities to changes in physical parameters. The method avoids many of the problems of incompatibility and inconsistency between the experimental and analytical modal data sets and enables the user to express confidence in measured data and modelling assumptions, allowing flexible but automated model updating.

Isothermal compressibility, isochoric heat capacity, and intrinsic pressure of KCl-NdCl3 melts

2010 ◽  
Vol 2010 (2) ◽  
pp. 146-149 ◽  
Author(s):  
V. I. Minchenko ◽  
I. V. Korzun ◽  
V. A. Khokhlov ◽  
V. N. Dokutovich
Keyword(s):  
Heat Capacity ◽  
Isothermal Compressibility ◽  
Isochoric Heat Capacity

Acoustic Phase Velocity Measurements along General Directions in Non-Isotropic Crystals. I. Elastic Properties of Monoclinic K3Co(CN)6

1971 ◽  
Vol 49 (12) ◽  
pp. 1597-1605 ◽  
Author(s):  
T. H. Chou ◽  
S. L. McBride ◽  
N. Rumin
Keyword(s):  
Elastic Constants ◽  
Experimental Error ◽  
Acoustic Velocity ◽  
Acoustic Energy ◽  
Perturbation Calculation ◽  
Velocity Measurements ◽  
Phase Velocities ◽  
Low Symmetry ◽  
Acoustic Phase

The complete elastic constants tensor of monoclinic potassium cobalticyanide [K3Co(CN)6] has been determined from measured ultrasonic phase velocities. These were obtained as a function of direction in several crystal planes by measuring the acoustic energy reflection coefficient at a liquid–solid interface as a function of angle and plane of incidence. The measurements were made at 27.6 MHz in p-xylene at 21.5 °C. The elastic constants were determined using an existing perturbation method. Velocities calculated from the derived elastic constants are in agreement with the measured velocities to within experimental error and the approximations in the perturbation calculation. The usefulness of this method for the determination of the elastic constants of low symmetry crystals is thus established. The Debye temperature of K3Co(CN)6 is estimated from the results to be 290 ± 10 °K with a corresponding mean acoustic velocity of 2560 ± 80 m/s.

Computation of Acoustic Velocity of Natural Gases With an Alternative Heat Capacity Ratio Equation and Application to Seismic Modeling

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Romulo Carvalho ◽  
Fernando Moraes
Keyword(s):  
Heat Capacity ◽  
Equations Of State ◽  
Acoustic Velocity ◽  
Fluid Composition ◽  
Seismic Modeling ◽  
Data Set ◽  
Natural Gases ◽  
Single Interface ◽  
Capacity Ratio ◽  
Extensive Experimental Data

Abstract We investigate three formulations for computing acoustic velocity of natural gas and derive an equation for the heat capacity ratio, which plays a central role in these formulations. The first formulation is a compilation of fundamental equations available in the engineering literature, referred to as the DASH formulation. The second formulation is a development from the first, in which we use the derived equation for the heat capacity ratio (modified DASH). The third formulation is a mainstream method implemented in Geoscience (BW formulation). All three formulations stem from virial Equations of State that take preponderance in the exploration stage, when the detailed fluid composition is unknown and compositional methods are frequently inapplicable. We test the formulations on an extensive experimental data set of acoustic velocity of natural gases and compare the resulting accuracies. Both DASH and modified DASH formulations provide significantly higher accuracy when compared to the BW formulation. Additionally, the modified DASH, as we derive in this work, has the highest accuracy at pressures above 7000 psi, a condition typically encountered in the Brazilian pre-salt reservoirs. In a final step, we investigate how these different formulations and corresponding accuracies in velocity computation may affect seismic modeling, using a single interface model between a dense gas reservoir and a sealing rock. A direct comparison of amplitude versus offset modeling using our modified DASH formulation and the BW formulation shows up to 50% difference in amplitude calculation in a sensitivity exercise, especially at the longer offsets and higher pressures.

scholarly journals Surprising Behaviour of the Wageningen B-Screw Series Polynomials

2020 ◽  
Vol 8 (3) ◽  
pp. 211 ◽  
Author(s):  
Stephan Helma
Keyword(s):  
Reynolds Number ◽  
Open Water ◽  
Measured Data ◽  
Design Stage ◽  
Data Sets ◽  
Preliminary Design ◽  
Preliminary Design Stage ◽  
Torque Values ◽  
Thrust And Torque ◽  
Over Time

Undoubtedly, the Wageningen B-screw Series is the most widely used systematic propeller series. It is very popular to preselect propeller dimensions during the preliminary design stage before performing a more thorough optimisation, but in the smaller end of the market it is often used to merely select the final propeller. Over time, the originally measured data sets were faired and scaled to a uniform Reynolds number of 2 · 106 to increase the reliability of the series. With the advent of the computer, polynomials for the thrust and torque values were calculated based on the available data sets. The measured data are typically presented in the well-known open-water curves of thrust and torque coefficients K T and K Q versus the advance coefficient J . Changing the presentation from these diagrams to efficiency maps reveals some unsuspected and surprising behaviours, such as multiple extrema when optimising for efficiency or even no optimum at all for certain conditions, where an optimum could be expected. These artefacts get more pronounced at higher pitch to diameter ratios and low blade numbers. The present work builds upon the paper presented by the author at the AMT’17 and smp’19 conferences and now includes the extended efficiency maps, as suggested by Danckwardt, for all propellers of the Wageningen B-screw Series.

Acoustic Velocity Measurements for Various Directions of Solid n-D2at 136 kbar and 300 K by Billouin Scattering in a Diamond Anvil Cell

1983 ◽  
Vol 22 (Part 1, No. 1) ◽  
pp. 52-56 ◽  
Author(s):  
Hiroyasu Shimizu ◽  
Takao Kumazawa ◽  
Edward M. Brody ◽  
Ho K. Mao ◽  
Peter M. Bell
Keyword(s):  
Diamond Anvil Cell ◽  
Acoustic Velocity ◽  
Velocity Measurements ◽  
Diamond Anvil
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