Anton Duchkov | Novosibirsk State University (original) (raw)
Papers by Anton Duchkov
International Geophysical Conference, Beijing, China, 24-27 April 2018, 2018
SEG Technical Program Expanded Abstracts 2017
64th EAGE Conference & Exhibition
Geophysical Prospecting
ABSTRACT In downhole microseismic monitoring, accurate event location relies on the accuracy of t... more ABSTRACT In downhole microseismic monitoring, accurate event location relies on the accuracy of the velocity model. The model can be estimated along with event locations. Anisotropic models are important to get accurate event locations. Taking anisotropy into account makes it possible to use additional data – two S‐wave arrivals generated due to shear‐wave splitting. However, anisotropic ray tracing requires iterative procedures for computing group velocities, which may become unstable around caustics. As a result, anisotropic kinematic inversion may become time consuming. In this paper, we explore the idea of using simplified ray tracing to locate events and estimate medium parameters. In the simplified ray‐tracing algorithm, the group velocity is assumed to be equal to phase velocity in both magnitude and direction. This assumption makes the ray‐tracing algorithm five times faster compared to ray tracing based on exact equations. We present a set of tests showing that given perforation‐shot data, one can use inversion based on simplified ray‐tracing even for moderate‐to‐strong anisotropic models. When there are no perforation shots, event‐location errors may become too large for moderately anisotropic media.
Tyumen 2013 - New Geotechnology for the Old Oil Provinces, 2013
Microseismic monitoring is a widely used technique in modern industry to image hydraulic fracturi... more Microseismic monitoring is a widely used technique in modern industry to image hydraulic fracturing operations. In this paper we plan to compare downhole and surface acquisition systems with a focus on their resolution power in microseismic event location, especially estimating their depth. Similar analysis was made in. The authors concluded that: (i) for surface array lateral positions are estimated robustly and are not sensitive to the velocity model, (ii) for their case study locations derived from surface monitoring showed less scattering in both vertical and horizontal directions compared to those derived from downhole data. Here we decided to revisit and check the second statement taking into account two points. First, we want to perform uncertainty analysis for apertures of surface arrays typically used in Russia. Second, we take into account that only P-wave information is used for surface data while both P-and S-waves are used for downhole data.
GEOPHYSICS
We present the first experimental acoustic properties measurement during gas-hydrate formation an... more We present the first experimental acoustic properties measurement during gas-hydrate formation and dissociation in crushed bituminous coal samples. We also compare the results with acoustic properties measurements during freezing and thawing water in the same samples. The results show a more complicated behavior that differs from similar experiments with sand. For the samples with adsorbed water, it does not freeze at anticipated temperatures, but acoustic velocities gradually increase with decreasing negative temperatures. It is caused by complicated pore surface structures, causing partial formation of ice/hydrate from bound water at different temperatures. We also observe that for the same samples the acoustic properties change significantly, becoming stronger during gas-hydrate formation than during freezing. We explain it by competitive sorption of methane and water in coal pore space; methane under pressure replaces part of the adsorbed water from micro-pores so that this wate...
GEOPHYSICS
Massive computation of seismic traveltimes is widely used in seismic processing, e.g. for the Kir... more Massive computation of seismic traveltimes is widely used in seismic processing, e.g. for the Kirchhoff migration of seismic and microseismic data. Implementation of the Kirchhoff migration operators utilizes large pre-computed traveltime tables (for all sources, receivers and densely sampled imaging points). We test the idea of using Artificial Neural Networks for approximating these traveltime tables. The neural network has to be trained for each velocity model, but then the whole traveltime table can be compressed by several orders of magnitude (up to six orders) to the size of less than one megabyte. This makes it convenient to store, share, and use such approximation for processing large data volumes. We discuss some aspects of choosing the neural-network architecture, training procedure, and optimal hyperparameters. On synthetic tests, we demonstrate reasonably accurate approximation of traveltimes by neural networks for various velocity models. Final synthetic test shows that...
66th EAGE Conference & Exhibition
SEG Technical Program Expanded Abstracts 2019
SEG Technical Program Expanded Abstracts 2016
Microseismic monitoring of hydrofrac is an actively developing technology utilizing various acqui... more Microseismic monitoring of hydrofrac is an actively developing technology utilizing various acquizition arrays. In this paper we consider processing of microseismic data recorded by specific surface network geometry-patch arrays (far separated local receiver groups). The project aim is to produce an optimal partial stacking of the data within patches for improving a signal to noise ratio for microseismic events detection and location. We propose to use a structure-tensor analysis for estimating directions of coherency in the data, which can be used for data stacking for each patch. Unlike to the standard slantstacking method, we do not scan all possible directions, but receive them as eigenvectors of the structure tensor. We used the synthetic data for testing our approach in presence of random and coherent noise, in the case of interfering events. The testing showed that the structure-tensor analysis provides robust coherent summation results. We also discuss the usefulness of the structure-tensor attributes for detecting (triggering) the arriving wave and separating body wave from surface waves based on the apparent velocity. (Less)
International Geophysical Conference, Beijing, China, 24-27 April 2018
SEG Technical Program Expanded Abstracts 2017
Russian Geology and Geophysics
A new system has been designed for laboratory physical modeling of hydrate-bearing sand samples a... more A new system has been designed for laboratory physical modeling of hydrate-bearing sand samples and measuring their acoustic properties at different temperatures and pressures. The system includes a pressure vessel, units of temperature control, external pressure, and gas/liquid delivery, and a unit for measuring velocities of acoustic waves. Measurements are carried out in 10–50 mm high cylindrical specimens 30 mm in diameter. The system provides methane hydrate formation in sand samples and their acoustic measurements for as long as several days due to automatic control. Hydrate-bearing samples are prepared by pressurized methane injection into pores of wet sand and are exposed to several cooling/heating cycles to increase hydrate formation rates. Hydrate-bearing samples have been prepared and travel times of acoustic P and S waves have been measured in dozens of successful experiments. Acoustic data confirm the formation of hydrates, with the related increase in wave velocities t...
SEG Technical Program Expanded Abstracts 2014, 2014
Summary Microseismic monitoring technology is widely used for the field control of hydraulic frac... more Summary Microseismic monitoring technology is widely used for the field control of hydraulic fracturing used in the production of unconventional hydrocarbon and geothermal resources. In this paper we discuss modified graph of microseismic data processing with accounting for seismic anisotropy. First, we describe implementation of interactive processing subroutine for polarization analysis of shear waves. It allows detecting shear-wave splitting and picking two shear-wave traveltimes for further inversion. Second, we optimize anisotropic ray-tracing algorithm so that to speed up massive kinematic modeling and inversion of microseismic data. Suggested optimized implementation of microseismic data processing graph can be used for massive simultaneous inversion of microseismic data containing traveltimes for hundreds of microseismic events.
Saint Petersburg 2012, 2012
In this paper we provide an overview of some concepts and results by S.V.Goldin in the field of g... more In this paper we provide an overview of some concepts and results by S.V.Goldin in the field of geometric theory of seismic imaging. Then we present some recent results on velocity continuation of seismic images developing his ideas. We will provide a few examples of Hamiltonians describing propagation of singularities during a velocity continuation of seismic (extended) images and propagation of isochrones in the framework of constant-offset migration.
71st EAGE Conference and Exhibition incorporating SPE EUROPEC 2009, 2009
Many processes in seismic data analysis and imaging can be identified with solution operators of ... more Many processes in seismic data analysis and imaging can be identified with solution operators of evolution equations. In this paper, we address the question whether isochrons defined by imaging operators can be dentified with wavefronts of solutions to an
14th SGEM GeoConference on SCIENCE AND TECHNOLOGIES IN GEOLOGY, EXPLORATION AND MINING, 2014
Proceedings 76th EAGE Conference and Exhibition 2014, 2014
ABSTRACT
SEG Technical Program Expanded Abstracts 2013, 2013
Conventionally perforation shots are used for calibration of the velocity model which is further ... more Conventionally perforation shots are used for calibration of the velocity model which is further used for microseismic event location. However, calibration of the velocity model becomes more problematic for anisotropic case because more unknown parameters have to be constrained from a limited number of perforation shots. Anisotropic models are nowadays gaining popularity in microseismic data processing flow. The main reason is that the majority of unconventional reservoirs are characterized by pronounced intrinsic anisotropy, e.g. shales.Perforation shots in vertical wells produce narrow azimuthal illumination of the medium that cannot be used for estimating anisotropic parameters. It is shown in the literature that azimuthally anisotropic velocity model can be constrained by inverting trveltimes from microseismic events alone. This rises question if perforation shot data is of any use at all for microseismic data processing in anisotropic media. Here we show that the addition of narrow angle perforation shot geometry, usual for vertical treated wells, does not constrain inversion any better than wide angle microseismic events data. On the other hand we show that the add of several perforation shots distributed horizontally (typical for horizontal treated wells) improves accuracy of calibrating horizontally transversely isotropic (HTI) velocity model.
International Geophysical Conference, Beijing, China, 24-27 April 2018, 2018
SEG Technical Program Expanded Abstracts 2017
64th EAGE Conference & Exhibition
Geophysical Prospecting
ABSTRACT In downhole microseismic monitoring, accurate event location relies on the accuracy of t... more ABSTRACT In downhole microseismic monitoring, accurate event location relies on the accuracy of the velocity model. The model can be estimated along with event locations. Anisotropic models are important to get accurate event locations. Taking anisotropy into account makes it possible to use additional data – two S‐wave arrivals generated due to shear‐wave splitting. However, anisotropic ray tracing requires iterative procedures for computing group velocities, which may become unstable around caustics. As a result, anisotropic kinematic inversion may become time consuming. In this paper, we explore the idea of using simplified ray tracing to locate events and estimate medium parameters. In the simplified ray‐tracing algorithm, the group velocity is assumed to be equal to phase velocity in both magnitude and direction. This assumption makes the ray‐tracing algorithm five times faster compared to ray tracing based on exact equations. We present a set of tests showing that given perforation‐shot data, one can use inversion based on simplified ray‐tracing even for moderate‐to‐strong anisotropic models. When there are no perforation shots, event‐location errors may become too large for moderately anisotropic media.
Tyumen 2013 - New Geotechnology for the Old Oil Provinces, 2013
Microseismic monitoring is a widely used technique in modern industry to image hydraulic fracturi... more Microseismic monitoring is a widely used technique in modern industry to image hydraulic fracturing operations. In this paper we plan to compare downhole and surface acquisition systems with a focus on their resolution power in microseismic event location, especially estimating their depth. Similar analysis was made in. The authors concluded that: (i) for surface array lateral positions are estimated robustly and are not sensitive to the velocity model, (ii) for their case study locations derived from surface monitoring showed less scattering in both vertical and horizontal directions compared to those derived from downhole data. Here we decided to revisit and check the second statement taking into account two points. First, we want to perform uncertainty analysis for apertures of surface arrays typically used in Russia. Second, we take into account that only P-wave information is used for surface data while both P-and S-waves are used for downhole data.
GEOPHYSICS
We present the first experimental acoustic properties measurement during gas-hydrate formation an... more We present the first experimental acoustic properties measurement during gas-hydrate formation and dissociation in crushed bituminous coal samples. We also compare the results with acoustic properties measurements during freezing and thawing water in the same samples. The results show a more complicated behavior that differs from similar experiments with sand. For the samples with adsorbed water, it does not freeze at anticipated temperatures, but acoustic velocities gradually increase with decreasing negative temperatures. It is caused by complicated pore surface structures, causing partial formation of ice/hydrate from bound water at different temperatures. We also observe that for the same samples the acoustic properties change significantly, becoming stronger during gas-hydrate formation than during freezing. We explain it by competitive sorption of methane and water in coal pore space; methane under pressure replaces part of the adsorbed water from micro-pores so that this wate...
GEOPHYSICS
Massive computation of seismic traveltimes is widely used in seismic processing, e.g. for the Kir... more Massive computation of seismic traveltimes is widely used in seismic processing, e.g. for the Kirchhoff migration of seismic and microseismic data. Implementation of the Kirchhoff migration operators utilizes large pre-computed traveltime tables (for all sources, receivers and densely sampled imaging points). We test the idea of using Artificial Neural Networks for approximating these traveltime tables. The neural network has to be trained for each velocity model, but then the whole traveltime table can be compressed by several orders of magnitude (up to six orders) to the size of less than one megabyte. This makes it convenient to store, share, and use such approximation for processing large data volumes. We discuss some aspects of choosing the neural-network architecture, training procedure, and optimal hyperparameters. On synthetic tests, we demonstrate reasonably accurate approximation of traveltimes by neural networks for various velocity models. Final synthetic test shows that...
66th EAGE Conference & Exhibition
SEG Technical Program Expanded Abstracts 2019
SEG Technical Program Expanded Abstracts 2016
Microseismic monitoring of hydrofrac is an actively developing technology utilizing various acqui... more Microseismic monitoring of hydrofrac is an actively developing technology utilizing various acquizition arrays. In this paper we consider processing of microseismic data recorded by specific surface network geometry-patch arrays (far separated local receiver groups). The project aim is to produce an optimal partial stacking of the data within patches for improving a signal to noise ratio for microseismic events detection and location. We propose to use a structure-tensor analysis for estimating directions of coherency in the data, which can be used for data stacking for each patch. Unlike to the standard slantstacking method, we do not scan all possible directions, but receive them as eigenvectors of the structure tensor. We used the synthetic data for testing our approach in presence of random and coherent noise, in the case of interfering events. The testing showed that the structure-tensor analysis provides robust coherent summation results. We also discuss the usefulness of the structure-tensor attributes for detecting (triggering) the arriving wave and separating body wave from surface waves based on the apparent velocity. (Less)
International Geophysical Conference, Beijing, China, 24-27 April 2018
SEG Technical Program Expanded Abstracts 2017
Russian Geology and Geophysics
A new system has been designed for laboratory physical modeling of hydrate-bearing sand samples a... more A new system has been designed for laboratory physical modeling of hydrate-bearing sand samples and measuring their acoustic properties at different temperatures and pressures. The system includes a pressure vessel, units of temperature control, external pressure, and gas/liquid delivery, and a unit for measuring velocities of acoustic waves. Measurements are carried out in 10–50 mm high cylindrical specimens 30 mm in diameter. The system provides methane hydrate formation in sand samples and their acoustic measurements for as long as several days due to automatic control. Hydrate-bearing samples are prepared by pressurized methane injection into pores of wet sand and are exposed to several cooling/heating cycles to increase hydrate formation rates. Hydrate-bearing samples have been prepared and travel times of acoustic P and S waves have been measured in dozens of successful experiments. Acoustic data confirm the formation of hydrates, with the related increase in wave velocities t...
SEG Technical Program Expanded Abstracts 2014, 2014
Summary Microseismic monitoring technology is widely used for the field control of hydraulic frac... more Summary Microseismic monitoring technology is widely used for the field control of hydraulic fracturing used in the production of unconventional hydrocarbon and geothermal resources. In this paper we discuss modified graph of microseismic data processing with accounting for seismic anisotropy. First, we describe implementation of interactive processing subroutine for polarization analysis of shear waves. It allows detecting shear-wave splitting and picking two shear-wave traveltimes for further inversion. Second, we optimize anisotropic ray-tracing algorithm so that to speed up massive kinematic modeling and inversion of microseismic data. Suggested optimized implementation of microseismic data processing graph can be used for massive simultaneous inversion of microseismic data containing traveltimes for hundreds of microseismic events.
Saint Petersburg 2012, 2012
In this paper we provide an overview of some concepts and results by S.V.Goldin in the field of g... more In this paper we provide an overview of some concepts and results by S.V.Goldin in the field of geometric theory of seismic imaging. Then we present some recent results on velocity continuation of seismic images developing his ideas. We will provide a few examples of Hamiltonians describing propagation of singularities during a velocity continuation of seismic (extended) images and propagation of isochrones in the framework of constant-offset migration.
71st EAGE Conference and Exhibition incorporating SPE EUROPEC 2009, 2009
Many processes in seismic data analysis and imaging can be identified with solution operators of ... more Many processes in seismic data analysis and imaging can be identified with solution operators of evolution equations. In this paper, we address the question whether isochrons defined by imaging operators can be dentified with wavefronts of solutions to an
14th SGEM GeoConference on SCIENCE AND TECHNOLOGIES IN GEOLOGY, EXPLORATION AND MINING, 2014
Proceedings 76th EAGE Conference and Exhibition 2014, 2014
ABSTRACT
SEG Technical Program Expanded Abstracts 2013, 2013
Conventionally perforation shots are used for calibration of the velocity model which is further ... more Conventionally perforation shots are used for calibration of the velocity model which is further used for microseismic event location. However, calibration of the velocity model becomes more problematic for anisotropic case because more unknown parameters have to be constrained from a limited number of perforation shots. Anisotropic models are nowadays gaining popularity in microseismic data processing flow. The main reason is that the majority of unconventional reservoirs are characterized by pronounced intrinsic anisotropy, e.g. shales.Perforation shots in vertical wells produce narrow azimuthal illumination of the medium that cannot be used for estimating anisotropic parameters. It is shown in the literature that azimuthally anisotropic velocity model can be constrained by inverting trveltimes from microseismic events alone. This rises question if perforation shot data is of any use at all for microseismic data processing in anisotropic media. Here we show that the addition of narrow angle perforation shot geometry, usual for vertical treated wells, does not constrain inversion any better than wide angle microseismic events data. On the other hand we show that the add of several perforation shots distributed horizontally (typical for horizontal treated wells) improves accuracy of calibrating horizontally transversely isotropic (HTI) velocity model.