E. Pervago - Academia.edu (original) (raw)

Papers by E. Pervago

3rd EEGS Meeting, 1997

Fig.3. Curves of sounding with Darray and their transformations for two models (see details in th... more Fig.3. Curves of sounding with Darray and their transformations for two models (see details in the text)

This work presents a new technology of well log interpretation for determining lithology, pore sy... more This work presents a new technology of well log interpretation for determining lithology, pore system characteristics, and saturations of double-porosity carbonate formations. This technology includes a unified petrophysical model for calculating the effective physical properties of carbonates and joint inversion of the following conventional logs: Pand S-wave transit times, resistivity, density, neutron porosity, gamma ray, and photoelectric absorption property. The inversion procedure consists in minimizing the cost function, which contains the sum of weighted square differences between the measured and calculated logs, and the regularization functional with additional information, initial model parameters, and ranges of their variations. The following petrophysical parameters are obtained by the inversion: a) volumes of limestone, dolomite, and shale; b) porosities of matrix, fractures, and vugs; c) connectivity of fractures and vugs; and d) initial and residual oil saturations i...

59th EAGE Conference & Exhibition, 1997

Izvestiya, Physics of the Solid Earth, 2020

Abstract The problem of calculating the reflection and transmission coefficients of elastic P -wa... more Abstract The problem of calculating the reflection and transmission coefficients of elastic P -wave incident from a porous half-space onto a fluid-filled crack is solved. The influence of capillary effects arising at the interface between a crack and a porous matrix on these coefficients is analyzed. In the first-order (single-) scattering approximation, the wave number of the effective P -wave propagating in a porous-fractured medium is calculated. It is shown that the hydrodynamic effects associated with fluid filtration at cracks’ boundaries in the field of an acoustic wave lead to significant frequency dispersion of the effective P -wave velocity.

56th EAEG Meeting, 1994

The first (mainly used) model for VES method is based on horizontally layered structure. The seco... more The first (mainly used) model for VES method is based on horizontally layered structure. The second one includes different deep objects, such as faults, horsts, grabens, domes, etc. We introduce the third model, which includes horizontal layers, deep objects, and many subsurface objects of different resistivities, referred to as subsurface inhomogeneities (SSIs).

3rd EEGS Meeting, 1997

For the control of a hvdro-geological situation on the channel Oder-Spree in Brandenburg land. Oe... more For the control of a hvdro-geological situation on the channel Oder-Spree in Brandenburg land. Oerman'' a firm Umweltanal y tik Brandenburg GmbH together with MSU developed hardware and software for aquatorial electrical surve. At construction of such instrumentation the basic problern consists in management of measuring process. The measurements on aquatona are carried oul in a movement in real time and without an opportunity to re-measure of separate readings. The software is intended for work in multitask operating systems as Windows lxx, that has caused necessztv of s nchronisation of all hardware parts in the process of measurement. The hardware complex inciudes the managing Notebook computer. AiD converter. clock generator and an analog measuring part. which inciudes a measuring cable with electrodes and amplifiers. On each site of measurement signals from 32 channels were measured during two seconds. As A/D 26 channel converter was used. switclung between groups of 16 channels was made on each site. Measurements of four AUSF values (ExL Ex2. Ex3. E). water resistivit and dipole axial sounding (DAS) on 20 spacings were maid, On each channel amplification a signal and canceling of industrial noise were made. To increase of reliabilit. the measurements ori each channel were carried Out with readings' accumulation and averaging. The instrumentation at the present provides the following operauons: Self-potential (SP) measurements of Ex component on threc channels and Ey component intended for search of water outflows and discharges. SP method is based on study filtration potentials. which are raised under action of groundwater. filtered through capillanes of rocks. Thus the water outflow through aquatona bonom causes negative SP potential. and the discharge subterranean water in the river raises positive SP anomalies: Resistivimetry (R) serves for determination of an electrical resistivity of water, which depends on its ininerahzation and can speci1 places of subterranean waters' discharge and sites of aqualorial pollution: Dipole axial sounding (DAS) is carried Out ith- .

69th EAGE Conference and Exhibition incorporating SPE EUROPEC 2007, 2007

In this paper we present an electromagnetic technology for non destructive surface inspection of ... more In this paper we present an electromagnetic technology for non destructive surface inspection of metallic pipelines that includes the determination of pipeline position and depth, assessment of technical condition of an insulation coating, and estimation of operating state of a cathodic protection system. This technology is based on the approximation of a metallic pipeline by a heterogeneous transmission line. In the model, the pipeline with damage of the insulated coating (variations of leakage resistance) and deterioration of the tube wall thickness (changes of tube impedance) is represented by uniform transmission line segments (piecewise model). This approach reduces the problem dimensions to 1D and allows us to obtain the analytical solution for calculating the voltage, current, and magnetic field distributions for single and group interconnected pipelines. Using the transmission line model we have simulated the voltage and current distributions for two interconnected pipelines with variable insulated coating in the low frequency range. The field operations consist in measurements of (1) the magnetic field created by the current flowing in a pipeline, (2) voltages on the control posts of cathodic protection, and (3) soil resistivity. We present the example of this technology application for the practical inspection of group interconnected oil pipelines.

Metal, Ceramic and Polymeric Composites for Various Uses, 2011

60th EAGE Conference and Exhibition, 1998

Pipelines are the systems of life-support of a modern society. In pipes oil and gas, tap and tech... more Pipelines are the systems of life-support of a modern society. In pipes oil and gas, tap and technical water, water for heating are supplied; household and industrial sewage are removed. The large part of pipes is dipped in ground.

5th EEGS-ES Meeting, 1999

The stream function described is employed for the presentation of 2D DC modeling results. The 2D ... more The stream function described is employed for the presentation of 2D DC modeling results. The 2D model is understood as a 2D medium with linear current electrodes, oriented along the inhomogeneities' strike direction. In this case both the medium and the electric field depend on two space coordinates only. Modeling becomes much easier than considering point current electrodes, where the electrical field always is three-dimensional. Meanwhile the actual results of such modeling are qualitatively equivalent to 3D modeling with point electrodes, as long as the measurements are conducted across the objects. The classical modeling presentation is in apparent resistivity which reflects an electric field distribution on the earth's surface. Quite often the connection of measured anomalies with a geoelectrical model is rather complex (fig. 1, A and C). The visualization of DC current lines simplifies understanding of the electric field's structure. Current lines are used in almost each textbook, but a practical technique for their construction is usually not included. The evident way for drawing current-lines is the step by step continuation of a line from some point along the electric field direction. The practical realization of such approach is not trivial. For a 2D field it is possible to use the stream-function. This function is often used in EM field modeling [flux function, Berdichevsky, 1984]. A contour map of the streamfunction corresponds to the streamline distribution. Thus the problem of current streamlines' construction is reduced to the calculation of the streamfunction in the research area. This can be achieved by calculating secondary surface charges, which are determined at 2D modeling, using Fredholm's integral equation of the second type relatively of electric field [Escola, 1979].

4th EEGS Meeting, 1998

Anisotropy of rocks' resistivity is a weak enough phenomenon in comparison with inhomogeneity inf... more Anisotropy of rocks' resistivity is a weak enough phenomenon in comparison with inhomogeneity influence. That is why we are trying to find an array being the most sensitive to anisotropy and to develop field survey and data processing technology for anisotropy and inhomogeneity influence estimation and separation. New step in this study gives arrow-type array. Fig.1. Spectra of arrays. Curves are marked with angle θ value.

61st EAGE Conference and Exhibition, 1999

The traditional resistivity sounding method deals with isolated sounding sites located casually o... more The traditional resistivity sounding method deals with isolated sounding sites located casually on profile or area and executed with logarithmic step in distante growth. This technology has very restricted possibilities.

57th EAEG Meeting, 1995

Resistivity method is usually applied for horizontally-layered media investigation as sounding, a... more Resistivity method is usually applied for horizontally-layered media investigation as sounding, and for inhomogeneous media as profiling.

Transport in Porous Media, 2009

Motivated by recent numerical results, we study the quantum phase transitions between Z2 spin liq... more Motivated by recent numerical results, we study the quantum phase transitions between Z2 spin liquid, Néel ordered, and various valence bond solid (VBS) states on the honeycomb and square lattices, with emphasis on the staggered VBS. In contrast to the well-understood columnar VBS order, the staggered VBS is not described by an XY order parameter with ZN anisotropy close to these quantum phase transitions. Instead, we demonstrate that on the honeycomb lattice, the staggered VBS is more appropriately described as an O(3) or CP(2) order parameter with cubic anisotropy, while on the square lattice it is described by an O(4) or CP(3) order parameter.

Journal of Petroleum Science and Engineering, 2007

Preview Determination of the water saturation is the crucial point in formation evaluation. For t... more Preview Determination of the water saturation is the crucial point in formation evaluation. For this purpose the well log data are widely used. Traditional estimation of the water saturation from the resistivity logs uses models described by Archie? s law. These models consider ...

Preview Determination of the water saturation is the crucial point in formation evaluation. For t... more Preview Determination of the water saturation is the crucial point in formation evaluation. For this purpose the well log data are widely used. Traditional estimation of the water saturation from the resistivity logs uses models described by Archie? s law. These models consider ...

3rd EEGS Meeting, 1997

Fig.3. Curves of sounding with Darray and their transformations for two models (see details in th... more Fig.3. Curves of sounding with Darray and their transformations for two models (see details in the text)

This work presents a new technology of well log interpretation for determining lithology, pore sy... more This work presents a new technology of well log interpretation for determining lithology, pore system characteristics, and saturations of double-porosity carbonate formations. This technology includes a unified petrophysical model for calculating the effective physical properties of carbonates and joint inversion of the following conventional logs: Pand S-wave transit times, resistivity, density, neutron porosity, gamma ray, and photoelectric absorption property. The inversion procedure consists in minimizing the cost function, which contains the sum of weighted square differences between the measured and calculated logs, and the regularization functional with additional information, initial model parameters, and ranges of their variations. The following petrophysical parameters are obtained by the inversion: a) volumes of limestone, dolomite, and shale; b) porosities of matrix, fractures, and vugs; c) connectivity of fractures and vugs; and d) initial and residual oil saturations i...

59th EAGE Conference & Exhibition, 1997

Izvestiya, Physics of the Solid Earth, 2020

Abstract The problem of calculating the reflection and transmission coefficients of elastic P -wa... more Abstract The problem of calculating the reflection and transmission coefficients of elastic P -wave incident from a porous half-space onto a fluid-filled crack is solved. The influence of capillary effects arising at the interface between a crack and a porous matrix on these coefficients is analyzed. In the first-order (single-) scattering approximation, the wave number of the effective P -wave propagating in a porous-fractured medium is calculated. It is shown that the hydrodynamic effects associated with fluid filtration at cracks’ boundaries in the field of an acoustic wave lead to significant frequency dispersion of the effective P -wave velocity.

56th EAEG Meeting, 1994

The first (mainly used) model for VES method is based on horizontally layered structure. The seco... more The first (mainly used) model for VES method is based on horizontally layered structure. The second one includes different deep objects, such as faults, horsts, grabens, domes, etc. We introduce the third model, which includes horizontal layers, deep objects, and many subsurface objects of different resistivities, referred to as subsurface inhomogeneities (SSIs).

3rd EEGS Meeting, 1997

For the control of a hvdro-geological situation on the channel Oder-Spree in Brandenburg land. Oe... more For the control of a hvdro-geological situation on the channel Oder-Spree in Brandenburg land. Oerman'' a firm Umweltanal y tik Brandenburg GmbH together with MSU developed hardware and software for aquatorial electrical surve. At construction of such instrumentation the basic problern consists in management of measuring process. The measurements on aquatona are carried oul in a movement in real time and without an opportunity to re-measure of separate readings. The software is intended for work in multitask operating systems as Windows lxx, that has caused necessztv of s nchronisation of all hardware parts in the process of measurement. The hardware complex inciudes the managing Notebook computer. AiD converter. clock generator and an analog measuring part. which inciudes a measuring cable with electrodes and amplifiers. On each site of measurement signals from 32 channels were measured during two seconds. As A/D 26 channel converter was used. switclung between groups of 16 channels was made on each site. Measurements of four AUSF values (ExL Ex2. Ex3. E). water resistivit and dipole axial sounding (DAS) on 20 spacings were maid, On each channel amplification a signal and canceling of industrial noise were made. To increase of reliabilit. the measurements ori each channel were carried Out with readings' accumulation and averaging. The instrumentation at the present provides the following operauons: Self-potential (SP) measurements of Ex component on threc channels and Ey component intended for search of water outflows and discharges. SP method is based on study filtration potentials. which are raised under action of groundwater. filtered through capillanes of rocks. Thus the water outflow through aquatona bonom causes negative SP potential. and the discharge subterranean water in the river raises positive SP anomalies: Resistivimetry (R) serves for determination of an electrical resistivity of water, which depends on its ininerahzation and can speci1 places of subterranean waters' discharge and sites of aqualorial pollution: Dipole axial sounding (DAS) is carried Out ith- .

69th EAGE Conference and Exhibition incorporating SPE EUROPEC 2007, 2007

In this paper we present an electromagnetic technology for non destructive surface inspection of ... more In this paper we present an electromagnetic technology for non destructive surface inspection of metallic pipelines that includes the determination of pipeline position and depth, assessment of technical condition of an insulation coating, and estimation of operating state of a cathodic protection system. This technology is based on the approximation of a metallic pipeline by a heterogeneous transmission line. In the model, the pipeline with damage of the insulated coating (variations of leakage resistance) and deterioration of the tube wall thickness (changes of tube impedance) is represented by uniform transmission line segments (piecewise model). This approach reduces the problem dimensions to 1D and allows us to obtain the analytical solution for calculating the voltage, current, and magnetic field distributions for single and group interconnected pipelines. Using the transmission line model we have simulated the voltage and current distributions for two interconnected pipelines with variable insulated coating in the low frequency range. The field operations consist in measurements of (1) the magnetic field created by the current flowing in a pipeline, (2) voltages on the control posts of cathodic protection, and (3) soil resistivity. We present the example of this technology application for the practical inspection of group interconnected oil pipelines.

Metal, Ceramic and Polymeric Composites for Various Uses, 2011

60th EAGE Conference and Exhibition, 1998

Pipelines are the systems of life-support of a modern society. In pipes oil and gas, tap and tech... more Pipelines are the systems of life-support of a modern society. In pipes oil and gas, tap and technical water, water for heating are supplied; household and industrial sewage are removed. The large part of pipes is dipped in ground.

5th EEGS-ES Meeting, 1999

The stream function described is employed for the presentation of 2D DC modeling results. The 2D ... more The stream function described is employed for the presentation of 2D DC modeling results. The 2D model is understood as a 2D medium with linear current electrodes, oriented along the inhomogeneities' strike direction. In this case both the medium and the electric field depend on two space coordinates only. Modeling becomes much easier than considering point current electrodes, where the electrical field always is three-dimensional. Meanwhile the actual results of such modeling are qualitatively equivalent to 3D modeling with point electrodes, as long as the measurements are conducted across the objects. The classical modeling presentation is in apparent resistivity which reflects an electric field distribution on the earth's surface. Quite often the connection of measured anomalies with a geoelectrical model is rather complex (fig. 1, A and C). The visualization of DC current lines simplifies understanding of the electric field's structure. Current lines are used in almost each textbook, but a practical technique for their construction is usually not included. The evident way for drawing current-lines is the step by step continuation of a line from some point along the electric field direction. The practical realization of such approach is not trivial. For a 2D field it is possible to use the stream-function. This function is often used in EM field modeling [flux function, Berdichevsky, 1984]. A contour map of the streamfunction corresponds to the streamline distribution. Thus the problem of current streamlines' construction is reduced to the calculation of the streamfunction in the research area. This can be achieved by calculating secondary surface charges, which are determined at 2D modeling, using Fredholm's integral equation of the second type relatively of electric field [Escola, 1979].

4th EEGS Meeting, 1998

Anisotropy of rocks' resistivity is a weak enough phenomenon in comparison with inhomogeneity inf... more Anisotropy of rocks' resistivity is a weak enough phenomenon in comparison with inhomogeneity influence. That is why we are trying to find an array being the most sensitive to anisotropy and to develop field survey and data processing technology for anisotropy and inhomogeneity influence estimation and separation. New step in this study gives arrow-type array. Fig.1. Spectra of arrays. Curves are marked with angle θ value.

61st EAGE Conference and Exhibition, 1999

The traditional resistivity sounding method deals with isolated sounding sites located casually o... more The traditional resistivity sounding method deals with isolated sounding sites located casually on profile or area and executed with logarithmic step in distante growth. This technology has very restricted possibilities.

57th EAEG Meeting, 1995

Resistivity method is usually applied for horizontally-layered media investigation as sounding, a... more Resistivity method is usually applied for horizontally-layered media investigation as sounding, and for inhomogeneous media as profiling.

Transport in Porous Media, 2009

Motivated by recent numerical results, we study the quantum phase transitions between Z2 spin liq... more Motivated by recent numerical results, we study the quantum phase transitions between Z2 spin liquid, Néel ordered, and various valence bond solid (VBS) states on the honeycomb and square lattices, with emphasis on the staggered VBS. In contrast to the well-understood columnar VBS order, the staggered VBS is not described by an XY order parameter with ZN anisotropy close to these quantum phase transitions. Instead, we demonstrate that on the honeycomb lattice, the staggered VBS is more appropriately described as an O(3) or CP(2) order parameter with cubic anisotropy, while on the square lattice it is described by an O(4) or CP(3) order parameter.

Journal of Petroleum Science and Engineering, 2007

Preview Determination of the water saturation is the crucial point in formation evaluation. For t... more Preview Determination of the water saturation is the crucial point in formation evaluation. For this purpose the well log data are widely used. Traditional estimation of the water saturation from the resistivity logs uses models described by Archie? s law. These models consider ...

Preview Determination of the water saturation is the crucial point in formation evaluation. For t... more Preview Determination of the water saturation is the crucial point in formation evaluation. For this purpose the well log data are widely used. Traditional estimation of the water saturation from the resistivity logs uses models described by Archie? s law. These models consider ...