Andrey Bakulin | UT Austin (original) (raw)

Papers by Andrey Bakulin

Research paper thumbnail of Physical modeling and theoretical studies of seismic refections from a fault zone

We simulate a fault/fracture zone in a physical modeling experiment as array of thin, air‐filled,... more We simulate a fault/fracture zone in a physical modeling experiment as array of thin, air‐filled, densely packed rectangular cracks that have different sizes and shapes. For a fixed surface area of the fault occupied by cracks and for a constant fracture porosity, we ...

Research paper thumbnail of Tube-Wave Reflections in Cased Boreholes

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

P097 Tube-Wave Reflections in Cased Boreholes D. Alexandrov (St.-Petersburg State University) B.M... more P097 Tube-Wave Reflections in Cased Boreholes D. Alexandrov (St.-Petersburg State University) B.M. Kashtan (St.- Petersburg State University) A.V. Bakulin (Shell International Exploration and Production Inc) & S.R. Ziatdinov* (St.-Petersburg State University) SUMMARY At low frequencies tube or Stoneley waves represent a dominant arrival propagating along boreholes. They can be excited by the source in a well or by external source due to conversion from other wave types. Tube wave experiences reflection at the bed boundaries borehole diameter changes and fractures or permeable zones. It was proven in previous studies that 1D effective wavenumber approach provides simple and accurate low-frequency description

Research paper thumbnail of Predicting Velocities under Stress in Anisotropic Formations - Model and Experimental Validation

Research paper thumbnail of Surface seismic with DAS: Looking deep and shallow at the same time

© 2018 SEG. Unlike conventional point sensors, Distributed Acoustic Sensing (DAS) has unique feat... more © 2018 SEG. Unlike conventional point sensors, Distributed Acoustic Sensing (DAS) has unique features allowing us to record multiple datasets with variable acquisition parameters set inside the recording box, while using one continuous recording cable and a single round of shooting. We reveal how these distinct features allow DAS to deliver multi-scale data and have the capability to focus on both the near surface and deeper targets simultaneously. We present synthetic and field examples of “deep” and “shallow” DAS surveys and demonstrate their effectiveness. The new capabilities of surface seismic with DAS technology comprise a sensing revolution that addresses long-standing near-surface issues in land seismic without compromising the deeper imaging

Research paper thumbnail of Shear-Wave Seismic and VSP with Virtual Sources

Research paper thumbnail of Estimation of fracture parameters of orthorhombic media from reflection seismic data

Research paper thumbnail of Processing Frequent 4D Land Seismic Data with Buried Sensors for CO2 Monitoring

In 2015, Saudi Aramco started a CO2 Water-Alternating-Gas (WAG) EOR pilot project in an onshore c... more In 2015, Saudi Aramco started a CO2 Water-Alternating-Gas (WAG) EOR pilot project in an onshore carbonate reservoir. To monitor lateral expansion of the CO2 plume, the area was instrumented with a hybrid surface/downhole permanent seismic monitoring system. This system consists of over 1000 buried seismic sensors at a depth of around 70 m, below the the depth of expected weathering layer to mitigate the time-lapse noise. Despite receiver burial, seismic data still suffers from numerous challenges including: significant amounts of high-amplitude coherent noise such as guided waves, mode conversions, and scattered energy; amplitude variations over space and time caused by source and receiver coupling; variability of wavelet shape and arrival times due to seasonal near-surface variations; and low signal-to-noise ratio (SNR). A novel processing workflow was designed for 4D processing of such data. The workflow involves five critical processes. First, the high-amplitude coherent noise is eliminated using FK-based techniques that are 4D compliant to preserve the reservoir changes between repeated seismic surveys. Second, a four-term joint surface-consistent amplitude-scaling algorithm resolves the amplitude variations. The algorithm allows both source and receiver terms to have different scalars for the same positions, but it restricts the other two terms to be position-invariant over different time-lapse surveys, as the window of analysis does not include the reservoir. This is to guarantee that the source and receiver terms are survey-dependent while the other two terms are survey-independent. Thus, the amplitude variability is linked to source and receiver positions over space and time. It also assures that the reservoir changes are not affected by changes in the overburden. Third, wavelet shape variations are addressed using a four-term joint surface-consistent spiking deconvolution algorithm that applies similar principle as the scaling algorithm. Fourth, the small variations in reflection times between different surveys (4D statics) caused by seasonal variations are corrected by a specialized surface-consistent residual statics algorithm using a common pilot derived from the base survey. Fifth, the pre-stack data is supergrouped to enhance the signal-to-noise ratio and repeatability. The processing workflow has been applied to frequent land 3D seismic data acquired over a CO2 WAG EOR pilot project in Saudi Arabia. As a result, we obtained very repeatable seismic images that may successfully detect small CO2-related changes in a stiff carbonate reservoir.

Research paper thumbnail of Accelerated deep learning-based estimation of wavefront dips and curvatures and their application to 3D prestack data enhancement

Second International Meeting for Applied Geoscience & Energy

Research paper thumbnail of Subsurface Velocity-Model Building Using Enhanced 3D Seismic-While-Drilling Data

83rd EAGE Annual Conference & Exhibition

Research paper thumbnail of Prestack Data Enhancement with Phase Substitution and Phase Corrections Guided by Local Multidimensional Stacking

82nd EAGE Annual Conference & Exhibition, 2021

Research paper thumbnail of An Efficiency-Improved Genetic Algorithm for Enhancing Challenging 3D Prestack Data Using Nonlinear Beamforming

82nd EAGE Annual Conference & Exhibition, 2021

Research paper thumbnail of Dual-band generative learning for low-frequency extrapolation in seismic land data

First International Meeting for Applied Geoscience & Energy Expanded Abstracts, 2021

Research paper thumbnail of Drillbit vibrations enable sonic logs prediction in lateral boreholes using machine learning

First International Meeting for Applied Geoscience & Energy Expanded Abstracts, 2021

Research paper thumbnail of Alignment and Comparison of Top Drive and Near-Bit Accelerometers for Seismic-While-Drilling

Saint Petersburg 2020, 2020

Research paper thumbnail of Permanent Buried Receiver Monitoring of a Carbonate Reservoir in a Desert Environment

Research paper thumbnail of Direct estimation of local wavefront attributes using deep learning

First International Meeting for Applied Geoscience & Energy Expanded Abstracts, 2021

Research paper thumbnail of Elastic near-surface model estimation from full waveforms by deep learning

SEG Technical Program Expanded Abstracts 2020, 2020

We thank Jan Walda from the University of Hamburg, mem-bers of the Seismic Modeling and Inversion... more We thank Jan Walda from the University of Hamburg, mem-bers of the Seismic Modeling and Inversion group (SMI) andthe Seismic Wave Analysis Group (SWAG) at KAUST for con-structive discussions. The research reported in this publica-tion was supported by funding from King Abdullah Universityof Science and Technology (KAUST), Thuwal, 23955-6900,Saudi Arabia and Saudi Aramco.

Research paper thumbnail of Virtual Shear-Wave Source Delivers a Reliable S-Wave Velocity Model for VSP Imaging

81st EAGE Conference and Exhibition 2019, 2019

Research paper thumbnail of Seismic imaging of vertical array data acquired using smart DAS uphole acquisition system

SEG Technical Program Expanded Abstracts 2018, 2018

Research paper thumbnail of Smart DAS upholes for simultaneous land near-surface characterization and subsurface imaging

The Leading Edge, 2017

A novel integrated land seismic imaging system that uses distributed acoustic sensing (DAS) in a ... more A novel integrated land seismic imaging system that uses distributed acoustic sensing (DAS) in a grid of shallow upholes is proposed. This system allows simultaneous land near-surface characterization and subsurface imaging in a cost-efficient manner. Using this fiber-optic system, uphole velocity surveys can be acquired at any time with a single shot, since all depth levels are recorded simultaneously. Dense grids of smart DAS upholes accurately characterize long-wavelength statics and reduce uncertainty in exploration for low-relief structures. In addition, connecting multiple upholes with a single fiber enables efficient acquisition of seismic surveys with buried vertical arrays, which can provide superior images of the deeper subsurface than surface seismic, but with improved accuracy, since they bypass most of the near-surface complexities. The smart DAS upholes can deliver on-demand surveys that simultaneously characterize the near surface and perform deep reflection imaging o...

Research paper thumbnail of Physical modeling and theoretical studies of seismic refections from a fault zone

We simulate a fault/fracture zone in a physical modeling experiment as array of thin, air‐filled,... more We simulate a fault/fracture zone in a physical modeling experiment as array of thin, air‐filled, densely packed rectangular cracks that have different sizes and shapes. For a fixed surface area of the fault occupied by cracks and for a constant fracture porosity, we ...

Research paper thumbnail of Tube-Wave Reflections in Cased Boreholes

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

P097 Tube-Wave Reflections in Cased Boreholes D. Alexandrov (St.-Petersburg State University) B.M... more P097 Tube-Wave Reflections in Cased Boreholes D. Alexandrov (St.-Petersburg State University) B.M. Kashtan (St.- Petersburg State University) A.V. Bakulin (Shell International Exploration and Production Inc) & S.R. Ziatdinov* (St.-Petersburg State University) SUMMARY At low frequencies tube or Stoneley waves represent a dominant arrival propagating along boreholes. They can be excited by the source in a well or by external source due to conversion from other wave types. Tube wave experiences reflection at the bed boundaries borehole diameter changes and fractures or permeable zones. It was proven in previous studies that 1D effective wavenumber approach provides simple and accurate low-frequency description

Research paper thumbnail of Predicting Velocities under Stress in Anisotropic Formations - Model and Experimental Validation

Research paper thumbnail of Surface seismic with DAS: Looking deep and shallow at the same time

© 2018 SEG. Unlike conventional point sensors, Distributed Acoustic Sensing (DAS) has unique feat... more © 2018 SEG. Unlike conventional point sensors, Distributed Acoustic Sensing (DAS) has unique features allowing us to record multiple datasets with variable acquisition parameters set inside the recording box, while using one continuous recording cable and a single round of shooting. We reveal how these distinct features allow DAS to deliver multi-scale data and have the capability to focus on both the near surface and deeper targets simultaneously. We present synthetic and field examples of “deep” and “shallow” DAS surveys and demonstrate their effectiveness. The new capabilities of surface seismic with DAS technology comprise a sensing revolution that addresses long-standing near-surface issues in land seismic without compromising the deeper imaging

Research paper thumbnail of Shear-Wave Seismic and VSP with Virtual Sources

Research paper thumbnail of Estimation of fracture parameters of orthorhombic media from reflection seismic data

Research paper thumbnail of Processing Frequent 4D Land Seismic Data with Buried Sensors for CO2 Monitoring

In 2015, Saudi Aramco started a CO2 Water-Alternating-Gas (WAG) EOR pilot project in an onshore c... more In 2015, Saudi Aramco started a CO2 Water-Alternating-Gas (WAG) EOR pilot project in an onshore carbonate reservoir. To monitor lateral expansion of the CO2 plume, the area was instrumented with a hybrid surface/downhole permanent seismic monitoring system. This system consists of over 1000 buried seismic sensors at a depth of around 70 m, below the the depth of expected weathering layer to mitigate the time-lapse noise. Despite receiver burial, seismic data still suffers from numerous challenges including: significant amounts of high-amplitude coherent noise such as guided waves, mode conversions, and scattered energy; amplitude variations over space and time caused by source and receiver coupling; variability of wavelet shape and arrival times due to seasonal near-surface variations; and low signal-to-noise ratio (SNR). A novel processing workflow was designed for 4D processing of such data. The workflow involves five critical processes. First, the high-amplitude coherent noise is eliminated using FK-based techniques that are 4D compliant to preserve the reservoir changes between repeated seismic surveys. Second, a four-term joint surface-consistent amplitude-scaling algorithm resolves the amplitude variations. The algorithm allows both source and receiver terms to have different scalars for the same positions, but it restricts the other two terms to be position-invariant over different time-lapse surveys, as the window of analysis does not include the reservoir. This is to guarantee that the source and receiver terms are survey-dependent while the other two terms are survey-independent. Thus, the amplitude variability is linked to source and receiver positions over space and time. It also assures that the reservoir changes are not affected by changes in the overburden. Third, wavelet shape variations are addressed using a four-term joint surface-consistent spiking deconvolution algorithm that applies similar principle as the scaling algorithm. Fourth, the small variations in reflection times between different surveys (4D statics) caused by seasonal variations are corrected by a specialized surface-consistent residual statics algorithm using a common pilot derived from the base survey. Fifth, the pre-stack data is supergrouped to enhance the signal-to-noise ratio and repeatability. The processing workflow has been applied to frequent land 3D seismic data acquired over a CO2 WAG EOR pilot project in Saudi Arabia. As a result, we obtained very repeatable seismic images that may successfully detect small CO2-related changes in a stiff carbonate reservoir.

Research paper thumbnail of Accelerated deep learning-based estimation of wavefront dips and curvatures and their application to 3D prestack data enhancement

Second International Meeting for Applied Geoscience & Energy

Research paper thumbnail of Subsurface Velocity-Model Building Using Enhanced 3D Seismic-While-Drilling Data

83rd EAGE Annual Conference & Exhibition

Research paper thumbnail of Prestack Data Enhancement with Phase Substitution and Phase Corrections Guided by Local Multidimensional Stacking

82nd EAGE Annual Conference & Exhibition, 2021

Research paper thumbnail of An Efficiency-Improved Genetic Algorithm for Enhancing Challenging 3D Prestack Data Using Nonlinear Beamforming

82nd EAGE Annual Conference & Exhibition, 2021

Research paper thumbnail of Dual-band generative learning for low-frequency extrapolation in seismic land data

First International Meeting for Applied Geoscience & Energy Expanded Abstracts, 2021

Research paper thumbnail of Drillbit vibrations enable sonic logs prediction in lateral boreholes using machine learning

First International Meeting for Applied Geoscience & Energy Expanded Abstracts, 2021

Research paper thumbnail of Alignment and Comparison of Top Drive and Near-Bit Accelerometers for Seismic-While-Drilling

Saint Petersburg 2020, 2020

Research paper thumbnail of Permanent Buried Receiver Monitoring of a Carbonate Reservoir in a Desert Environment

Research paper thumbnail of Direct estimation of local wavefront attributes using deep learning

First International Meeting for Applied Geoscience & Energy Expanded Abstracts, 2021

Research paper thumbnail of Elastic near-surface model estimation from full waveforms by deep learning

SEG Technical Program Expanded Abstracts 2020, 2020

We thank Jan Walda from the University of Hamburg, mem-bers of the Seismic Modeling and Inversion... more We thank Jan Walda from the University of Hamburg, mem-bers of the Seismic Modeling and Inversion group (SMI) andthe Seismic Wave Analysis Group (SWAG) at KAUST for con-structive discussions. The research reported in this publica-tion was supported by funding from King Abdullah Universityof Science and Technology (KAUST), Thuwal, 23955-6900,Saudi Arabia and Saudi Aramco.

Research paper thumbnail of Virtual Shear-Wave Source Delivers a Reliable S-Wave Velocity Model for VSP Imaging

81st EAGE Conference and Exhibition 2019, 2019

Research paper thumbnail of Seismic imaging of vertical array data acquired using smart DAS uphole acquisition system

SEG Technical Program Expanded Abstracts 2018, 2018

Research paper thumbnail of Smart DAS upholes for simultaneous land near-surface characterization and subsurface imaging

The Leading Edge, 2017

A novel integrated land seismic imaging system that uses distributed acoustic sensing (DAS) in a ... more A novel integrated land seismic imaging system that uses distributed acoustic sensing (DAS) in a grid of shallow upholes is proposed. This system allows simultaneous land near-surface characterization and subsurface imaging in a cost-efficient manner. Using this fiber-optic system, uphole velocity surveys can be acquired at any time with a single shot, since all depth levels are recorded simultaneously. Dense grids of smart DAS upholes accurately characterize long-wavelength statics and reduce uncertainty in exploration for low-relief structures. In addition, connecting multiple upholes with a single fiber enables efficient acquisition of seismic surveys with buried vertical arrays, which can provide superior images of the deeper subsurface than surface seismic, but with improved accuracy, since they bypass most of the near-surface complexities. The smart DAS upholes can deliver on-demand surveys that simultaneously characterize the near surface and perform deep reflection imaging o...