Analytical method to estimate the complex permittivity of oil samples

In this paper, an analytical method to estimate the complex dielectric constant of liquids is presented. The method is based on the measurement of the transmission coefficient in an embedded microstrip line loaded with a complementary split ring resonator (CSRR), which is etched in the ground plane. From this response, the dielectric constant and loss tangent of the liquid under test (LUT) can be extracted, provided that the CSRR is surrounded by such LUT, and the liquid level extends beyond the region where the electromagnetic fields generated by the CSRR are present. For that purpose, a liquid container acting as a pool is added to the structure. The main advantage of this method, which is validated from the measurement of the complex dielectric constant of olive and castor oil, is that reference samples for calibration are not required.Ministerio de Economía y Competitividad TEC2013-40600-RGeneralitat de Catalunya 2014SGR-157Junta de Andalucía P12-TIC-1435Ministerio de Economía y Competitividad TEC2013-41913-PMinisterio de Economía y Competitividad TEC2016-75650-RInstitució Catalana de Recerca i Estudis Avançat

A microwave cavity resonator sensor for water-in-oil measurements

Online monitoring of Water-Liquid Ratio (WLR) in multiphase flow is key in petroleum production, processing and transportation. The usual practice in the field is to manually collect offline samples for laboratory analysis, which delays data availability and prevents real time intervention and optimization. A highly accurate and robust sensing method is needed for online measurements in the lower end of WLR range (0%–5%), especially for fiscal metering and custody transfer of crude oil, as well as to ensure adequate flow assurance prevention and remedial solutions. This requires a highly sensitive sensing principle along with a highly precise measurement instrument, packaged together in a sufficiently robust manner for use in the field. In this paper, a new sensing principle is proposed, based on the open-ended microwave cavity resonator and near wall surface perturbation, for non-intrusive measurement of WLR. In the proposed concept, the electromagnetic fringe field of a cylindrical cavity resonator is used to probe the liquid near the pipe wall. Two of the cylindrical cavity resonance modes, TM010 and TM011 are energized for measurements and the shift in the resonance frequency is used to estimate liquid permittivity and the WLR. Electromagnetic simulations in the microwave frequency range of 4 GHz to 7 GHz are used for proof-of-concept and sensitivity studies. A sensor prototype is fabricated and its functionality demonstrated with flowing oil-water mixtures in the WLR range of 0–5%. The frequency range of the proposed sensors is 4.4–4.6 GHz and 6.1–6.6 GHz for modes TM010 and TM011, respectively. The TM011 mode shows much higher sensitivity (41.6 MHz/WLR) than the TM010 mode (3.8 MHz/WLR). The proposed sensor consists of a 20 mm high cylinder, with a diameter of 30 mm and Poly-Ether-Ether-Ketone (PEEK) filler. The non-intrusiveness of the sensor, along with the high sensitivity in the resonance shift, makes it attractive for practical applications

Towards Accurate Dielectric Property Retrieval of Biological Tissues for Blood Glucose Monitoring

(c) 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This post-acceptance version of the paper is essentially complete, but may differ from the official copy of record, which can be found at the following web location (subscription required to access full paper): http://dx.doi.org/10/1109/TMTT.2014.2365019

Estimation of in-situ fluid properties from the combined interpretation of nuclear, dielectric, optical, and magnetic resonance measurements

During the last few decades, the quantification of hydrocarbon pore volume from borehole measurements has been widely studied for reservoir descriptions. Relatively less effort has been devoted to estimating in-situ fluid properties because (1) acquiring fluid samples is expensive, (2) reservoir fluids are a complex mixture of various miscible and non-miscible phases, and (3) they depend on environmental factors such as temperature and pressure. This dissertation investigates the properties of fluid mixtures based on various manifestations of their electromagnetic properties from the MHz to the THz frequency ranges. A variety of fluids, including water, alcohol, alkane, aromatics, cyclics, ether, and their mixtures, are analyzed with both laboratory experiments and numerical simulations. A new method is introduced to quantify in-situ hydrocarbon properties from borehole nuclear measurements. The inversion-based estimation method allows depth-continuous assessment of compositional gradients at in-situ conditions and provides thermodynamically consistent interpretations of reservoir fluids that depend greatly on phase behavior. Applications of this interpretation method to measurements acquired in two field examples, including one in a gas-oil transition zone, yielded reliable and verifiable hydrocarbon compositions. Dielectric properties of polar liquid mixtures were analyzed in the frequency range from 20 MHz to 20 GHz at ambient conditions. The Havriliak-Negami (HN) model was adapted for the estimation of dielectric permittivity and relaxation time. These experimental dielectric properties were compared to Molecular Dynamics (MD) simulations. Additionally, thermodynamic properties, including excess enthalpy, density, number of hydrogen bonds, and effective self-diffusion coefficient, were computed to cross-validate experimental results. Properties predicted from MD simulations are in excellent agreement with experimental measurements. The three most common optical spectroscopy techniques, i.e. Near Infrared (NIR), Infrared, and Raman, were applied for the estimation of compositions and physical properties of liquid mixtures. Several analytical techniques, including Principal Component Analysis (PCA), Radial Basis Functions (RBF), Partial Least-Squares Regression (PLSR), and Artificial Neural Networks (ANN), were separately implemented for each spectrum to build correlations between spectral data and properties of liquid mixtures. Results show that the proposed methods yield prediction errors from 1.5% to 22.2% smaller than those obtained with standard multivariate methods. Furthermore, the errors can be decreased by combining NIR, Infrared, and Raman spectroscopy measurements. Lastly, the ¹H NMR longitudinal relaxation properties of various liquid mixtures were examined with the objective of detecting individual components. Relaxation times and diffusion coefficients obtained via MD simulations for these mixtures are in agreement with experimental data. Also, the ¹H-¹H dipole-dipole relaxations for fluid mixtures were decomposed into the relaxations emanate from the intramolecular and intermolecular interactions. The quantification of intermolecular interactions between the same molecules and different molecules reveals how much each component contributes to the total NMR longitudinal relaxation of the mixture as well as the level of interactions between different fluids. Both experimental and numerical simulation results documented in this dissertation indicate that selecting measurement techniques that can capture the physical property of interest and maximize the physical contrasts between different components is important for reliable and accurate in-situ fluid identificationPetroleum and Geosystems Engineerin

Investigation Of Polarization And Depolarization: Current Measurements For The Assessment Of Oil-Paper Insulation Of Aged Transformers

Moisture and ageing strongly influence the dielectric properties of oilrpaper insulation system of power transformer. Moisture measurement in oil sample generally gives inconclusive information since oilrpaper moisture equilibrium is temperature dependent and takes a long time to be in equilibrium. Direct moisture measurement of paper sample is not practicable for in-service transformers. The measurement and evaluation of the 'dielectric response'and conductivity is one possible way of diagnosing a transformer insulation condition. In a recent research project, polarization and depolarization current measurement has been used for assessing the condition of oilrpaper insulation. The polarization and depolarization current PDC analysis is a non-destructive dielectric testing method for determining the conductivity and moisture content of insulation materials in a transformer. On the basis of this analysis it is possible to take further actions like oilrefurbishment, drying or replacement of the winding of the transformer. This paper presents a description of the PDC technique with the physical and mathematical background and some results of PDC measurements on several transformers. Analyses and interpretation of the field test data are also presented in this paper

Electromagnetic Scattering and Statistic Analysis of Clutter from Oil Contaminated Sea Surface

In order to investigate the electromagnetic (EM) scattering characteristics of the three dimensional sea surface contaminated by oil, a rigorous numerical method multilevel fast multipole algorithm (MLFMA) is developed to preciously calculate the electromagnetic backscatter from the two-layered oil contaminated sea surface. Illumination window and resistive window are combined together to depress the edge current induced by artificial truncation of the sea surface. By using this combination, the numerical method can get a high efficiency at a less computation cost. The differences between backscatters from clean sea and oil contaminated sea are investigated with respect to various incident angles and sea states. Also, the distribution of the sea clutter is examined for the oil-spilled cases in this paper

Time domain analysis of switching transient fields in high voltage substations

Switching operations of circuit breakers and disconnect switches generate transient currents propagating along the substation busbars. At the moment of switching, the busbars temporarily acts as antennae radiating transient electromagnetic fields within the substations. The radiated fields may interfere and disrupt normal operations of electronic equipment used within the substation for measurement, control and communication purposes. Hence there is the need to fully characterise the substation electromagnetic environment as early as the design stage of substation planning and operation to ensure safe operations of the electronic equipment. This paper deals with the computation of transient electromagnetic fields due to switching within a high voltage air-insulated substation (AIS) using the finite difference time domain (FDTD) metho

Analysis of sandstone pore space fluid saturation and mineralogy variation via application of monostatic K-band frequency modulated continuous wave radar

In this paper we present the preliminary findings from a world first investigation into monostatic frequency modulated continuous wave (FMCW) radar analysis of porous sandstones and their fluid content. FMCW results, within 24 to 25.5 GHz, provide insights into the rock/pore system as well as into mineral and liquid distributions, both crucial for quantitative representation of the fluid-rock system for subsequent assessment of the sandstones. Sandstone samples, here characterised using known techniques of energy dispersive x-ray analysis, gaseous secondary electron and backscattered electron imaging are: Darney, Lazonby Locharbriggs and Red St. Bees sandstones, with FMCW results indicating that, in the K-Band, calculated values for relative permittivity, utilising free-space radiation reflection data, give results that are consistent with the known rock elemental constituents, where each sandstone has different distributions of the dominant quartz and subsidiary other minerals and of grain size and shape distributions. The experimental results support the sensitivity of this sensing modality to variances in rock properties in typical sandstones with complex relative permittivity, ε_r^*, values for unsaturated sandstones ranging from 5.76 to 6.76 and from 12.96 to 48.3 for partially saturated sandstones, with the highest values indicating high permittivity mineral inclusion and/or grain angularity