Rapid Modeling and Inversion-based Interpretation of Borehole Acoustic Measurements Acquired in Isotropic and Vertical Transversely Isotropic Formations

Download Rapid Modeling and Inversion-based Interpretation of Borehole Acoustic Measurements Acquired in Isotropic and Vertical Transversely Isotropic Formations PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 336 pages
Book Rating : 4.:/5 (13 download)

DOWNLOAD NOW!


Book Synopsis Rapid Modeling and Inversion-based Interpretation of Borehole Acoustic Measurements Acquired in Isotropic and Vertical Transversely Isotropic Formations by : Elsa Maalouf

Download or read book Rapid Modeling and Inversion-based Interpretation of Borehole Acoustic Measurements Acquired in Isotropic and Vertical Transversely Isotropic Formations written by Elsa Maalouf and published by . This book was released on 2017 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Borehole acoustic measurements are often affected by instrument noise, motion and eccentricity, environmental conditions, and spatial averaging that can compromise the accuracy of elastic properties of rock formations calculated with conventional interpretation methods. Forward and inverse modeling can be used to improve the interpretation of acoustic logs acquired in the presence of spatially complex rock formations and adverse borehole conditions. However, forward modeling of acoustic modes often requires time-consuming numerical algorithms. The main objective of this dissertation is to develop fast-forward modeling and inversion-based interpretation procedures of borehole acoustic logs for isotropic and vertical transversely isotropic (VTI) formations. Fast-forward modeling is achieved with spatial sensitivity functions which are calculated from frequency-domain linear perturbation theory of borehole acoustic modes. Spatial sensitivity functions quantify both the dependence of measured slowness on elastic properties and the spatial averaging introduced by acoustic tools. Fast-forward modeling using spatial sensitivity functions is applied to synthetic examples that include thin layers, anisotropy, and dipping layers, and is successfully validated with numerical simulations performed with finite-difference and finite-element methods. Two inversion-based interpretation methods are then developed: (1) a physics-based inversion method to reduce noise and spatial averaging effects on acoustic logs acquired in horizontally layered formations penetrated by vertical wells, and (2) a sequential inversion method to estimate stiffness coefficients of VTI formations from multi-frequency flexural/quadrupole, Stoneley, and compressional logs. The physics-based inversion method is applied to mitigate measurement noise and spatial averaging effects of acoustic logs acquired in two hydrocarbon reservoirs. Results confirm the accuracy and reliability of the estimated layer-by-layer elastic properties compared to conventional numerical filters and are obtained in less than 14 CPU seconds for a 100 ft-depth log. In VTI formations penetrated by vertical wells, sequential inversion is applied to estimate layer-by-layer stiffness coefficients of synthetic formations from borehole acoustic logs. Results indicate that mitigating spatial averaging of frequency-dependent slowness logs prior to inversion improves the layer-by-layer estimation of slownesses by a factor of 2, and that sequential inversion yields accurate and reliable estimates of rock stiffness coefficients. Finally, in high-angle wells fast-forward modeling yields flexural slownesses measured with orthogonal dipoles with 2% relative errors and in 3 CPU minutes for a log consisting of 50 measured-depth samples, compared to 15 CPU hours when using finite-difference simulation methods. Analysis of field and synthetic examples confirms that inversion-based interpretation methods yield more accurate estimations of elastic properties than conventional sonic-log interpretation procedures. Spatial sensitivity functions constitute a fast, reliable, and efficient alternative for interpreting acoustic logs acquired in isotropic and VTI formations.

Acoustic Waves in Boreholes

Download Acoustic Waves in Boreholes PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 9780849388903
Total Pages : 284 pages
Book Rating : 4.3/5 (889 download)

DOWNLOAD NOW!


Book Synopsis Acoustic Waves in Boreholes by : Frederick L. Paillet

Download or read book Acoustic Waves in Boreholes written by Frederick L. Paillet and published by CRC Press. This book was released on 1991-10-29 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introducing the first, self-contained reference on acoustic waveform logging Acoustic measurements in boreholes were first made as a specialized logging technique in geological exploration, but recent advances have greatly expanded the potential applications of this technique. Acoustic Waves in Boreholes provides a thorough review of the theory and interpretation techniques needed to realize these applications, emphasizing the role of guided modes and critically refracted waves in determining the characteristics of recorded waveforms. Topics covered in this comprehensive volume include the seismic properties of rocks; propagation of axisymmetric waves along fluid-filled boreholes in isotropic rocks; and symmetric and nonsymmetric sources in isotropic, transversely isotropic, and porous, permeable formations in open and cased boreholes. Each chapter includes the theory of synthetic microseismogram computation, interpretation and data inversion techniques illustrated using computed seismograms, and case histories using experimental data. Appendices providing the mathematical formulation needed to compute microseismograms, with a single consistent notation used throughout, are also included in appropriate chapters. The wide range of geomechanical properties covered in this book will interest exploration geophysicists, reservoir engineers, civil engineers, geologists, and soil scientists.

Acoustic Waves in Boreholes

Download Acoustic Waves in Boreholes PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 1000943305
Total Pages : 282 pages
Book Rating : 4.0/5 (9 download)

DOWNLOAD NOW!


Book Synopsis Acoustic Waves in Boreholes by : Frederick L. Paillet

Download or read book Acoustic Waves in Boreholes written by Frederick L. Paillet and published by CRC Press. This book was released on 2023-07-14 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introducing the first, self-contained reference on acoustic waveform logging Acoustic measurements in boreholes were first made as a specialized logging technique in geological exploration, but recent advances have greatly expanded the potential applications of this technique. Acoustic Waves in Boreholes provides a thorough review of the theory and interpretation techniques needed to realize these applications, emphasizing the role of guided modes and critically refracted waves in determining the characteristics of recorded waveforms. Topics covered in this comprehensive volume include the seismic properties of rocks; propagation of axisymmetric waves along fluid-filled boreholes in isotropic rocks; and symmetric and nonsymmetric sources in isotropic, transversely isotropic, and porous, permeable formations in open and cased boreholes. Each chapter includes the theory of synthetic microseismogram computation, interpretation and data inversion techniques illustrated using computed seismograms, and case histories using experimental data. Appendices providing the mathematical formulation needed to compute microseismograms, with a single consistent notation used throughout, are also included in appropriate chapters. The wide range of geomechanical properties covered in this book will interest exploration geophysicists, reservoir engineers, civil engineers, geologists, and soil scientists.

Quantitative Borehole Acoustic Methods

Download Quantitative Borehole Acoustic Methods PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 9780080440514
Total Pages : 280 pages
Book Rating : 4.4/5 (45 download)

DOWNLOAD NOW!


Book Synopsis Quantitative Borehole Acoustic Methods by : X.M. Tang

Download or read book Quantitative Borehole Acoustic Methods written by X.M. Tang and published by Elsevier. This book was released on 2004-01-27 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic logging is a multidisciplinary technology involving basic theory, instrumentation, and data processing/interpretation methodologies. The advancement of the technology now allows for a broad range of measurements to obtain formation properties such as elastic wave velocity and attenuation, formation permeability, and seismic anisotropy that are important for petroleum reservoir exploration. With these advances, it is easier to detect and characterize formation fractures, estimate formation stress field, and locate/estimate petroleum reserves. The technology has evolved from the monopole acoustic logging into the multipole, including dipole, cross-dipole, and even quadrupole, acoustic logging measurements. The measurement process has developed from the conventional wireline logging into the logging-while-drilling stage. For such a fast developing technology with applications that are interesting to readers of different backgrounds, it is necessary to have systematic documentation of the discipline, including the theory, methods, and applications, as well as the technology's past, present, and near future development trends. Quantitative Borehole Acoustic Methods provides such documentation, with emphasis on the development over the past decade. Although considerable effort has been made to provide a thorough basis for the theory and methodology development, emphasis is placed on the applications of the developed methods. The applications are illustrated with field data examples. Many of the acoustic waveform analysis/processing methods described in the book are now widely used in the well logging industry.

Rapid Modeling of Borehole Measurements of Nuclear Magnetic Resonance Via Spatial Sensitivity Functions

Download Rapid Modeling of Borehole Measurements of Nuclear Magnetic Resonance Via Spatial Sensitivity Functions PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)

DOWNLOAD NOW!


Book Synopsis Rapid Modeling of Borehole Measurements of Nuclear Magnetic Resonance Via Spatial Sensitivity Functions by : Mohammad Albusairi

Download or read book Rapid Modeling of Borehole Measurements of Nuclear Magnetic Resonance Via Spatial Sensitivity Functions written by Mohammad Albusairi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Borehole measurements of Nuclear Magnetic Resonance (NMR) are routinely used to estimate in situ rock and fluid properties. Conventional NMR interpretation methods often neglect bed-boundary, mud-filtrate invasion, layer-thickness, and layer-dip effects in the calculation of fluid volumetric concentrations and NMR relaxation-diffusion correlations. Such effects introduce notable spatial averaging of intrinsic rock and fluid properties across thinly-bedded formations or in the vicinity of boundaries between layers exhibiting large property contrasts. Furthermore, the interpretation of NMR measurements entails major technical challenges in horizontal layers penetrated by high-angle and horizontal wells (HAHz) or across dipping layers penetrated by a vertical well. Three-dimensional (3D) geometrical effects, coupled with spatially and petrophysically heterogeneous rocks, may bias petrophysical estimates obtained from borehole NMR measurements when using interpretation procedures designed for vertical wells and horizontal layers. Forward modeling and inversion methods can mitigate the aforementioned effects and improve the accuracy of true layer properties in the presence of mud-filtrate invasion and borehole environmental and 3D geometrical effects across spatially complex formations. This dissertation introduces a fast and accurate algorithm to simulate borehole NMR measurements using the concept of spatial sensitivity functions (SSFs) that honor NMR physics and explicitly incorporate tool, borehole, and geometrical properties. To that end, a 3D multiphysics forward model is developed that couples NMR tool properties, magnetization time evolution, and electromagnetic propagation to derive the 3D spatial sensitivity maps associated with a specific borehole instrument. Additionally, a multifluid relaxation model based on Brownstein-Tarr’s equation is introduced to estimate layer-by-layer NMR porosity decays and relaxation-diffusion correlations from pore-size-dependent rock and fluid properties. The latter model is convolved with the SSFs to reproduce borehole NMR measurements acquired with advanced pulsing sequences (e.g., diffusion-editing and saturation recovery sequences). Results indicate that the spatial sensitivity of NMR measurements is controlled by porosity, electrical conductivity, excitation pulse duration, and tool geometry. The SSF-derived forward approximation is benchmarked and verified against 3D multiphysics simulations for a series of synthetic cases with variable bed thickness and petrophysical properties, as well as in the presence of mud-filtrate invasion. It is shown that the approximation can be executed in a few seconds of central processing unit (CPU), by a factor of 1000 times faster than rigorous multiphysics calculations, with maximum root-mean- square errors (RMSE) of 1%. On average, the fast approximation via SSFs reproduces borehole NMR measurements in 0.08 seconds of CPU time per logging measurement and can therefore be used for real-time calculations and interpretations. Next, the NMR forward modeling approximation is implemented to simulate measurements acquired across dipping formations penetrated by deviated wells in the presence of mud-filtrate invasion. Borehole NMR measurements are simulated by transforming a dipping layered model penetrated by an arbitrary well trajectory into an apparent layered model probed by a vertical well. This work compares the effect of radial length of investigation (DOI) from the three distinct NMR acquisition shells at 3.81 cm (1 in), 6.35 cm (2.5 in) and 10.16 cm (4 in), to integrate borehole NMR measurements acquired in 3D complex geometries. It is found that thinly-bedded formations and their petrophysical properties can be resolved with limited measurement resolution in HAHz wells and highly dipping formations. In thinly-bedded layers (e.g., thinner than 0.15 m) probed by a vertical well, spatial averaging effects bias the NMR porosity logs acquired with high vertical resolution (e.g., sampling rate equals to 2.54 cm). Conversely, formation geometrical and petrophysical properties can be accurately estimated across high apparent-dip formations. It is found that the shallower NMR acquisition shell (3.81 cm) is the least affected by bed-boundary averaging with increasing apparent dip. Moreover, the increase in apparent dip shifts the location of apparent bed boundaries. The latter phenomenon is more pronounced at deeper radial DOI. Interpretation procedures must mitigate such geometrical effects to accurately detect true bed boundaries and estimate layer-by-layer petrophysical properties

Fast Forward Modeling and Inversion of Borehole Sonic Measurements Using Spatial Sensitivity Functions

Download Fast Forward Modeling and Inversion of Borehole Sonic Measurements Using Spatial Sensitivity Functions PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 408 pages
Book Rating : 4.:/5 (923 download)

DOWNLOAD NOW!


Book Synopsis Fast Forward Modeling and Inversion of Borehole Sonic Measurements Using Spatial Sensitivity Functions by : Shan Huang (Ph. D.)

Download or read book Fast Forward Modeling and Inversion of Borehole Sonic Measurements Using Spatial Sensitivity Functions written by Shan Huang (Ph. D.) and published by . This book was released on 2015 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Borehole sonic measurements are widely used by petrophysicists to estimate in-situ dynamic elastic properties of rock formations. The estimated formation properties typically guide the interpretation of seismic amplitude measurements in the exploration and development of hydrocarbon reservoirs. Due to limitations in vertical resolution, borehole sonic measurements (sonic logs) provide spatially averaged values of formation properties in thinly bedded rocks. In addition, mud-filtrate invasion and near-wellbore formation damage can bias the elastic properties estimated from sonic logs. The interpretation of sonic logs in high angle (HA) and horizontal (HZ) wells is even more challenging because of three-dimensional geometrical effects and anisotropy. A reliable approach to account for geometrical effects in the interpretation of sonic logs is the implementation of forward modeling and inversion techniques. However, the computation time required to model the direct problem, namely wave propagation in the borehole environment, severely constraints the usage of inversion approaches in sonic-log interpretation. This dissertation develops new methods for the rapid simulation of sonic logs using the concept of spatial sensitivity functions. Sonic spatial sensitivity functions are equivalent to the Green's function of a particular sonic measurement; they also serve as weighting matrices to map formation elastic properties into the respective measurement space. Application of sensitivity functions to challenging synthetic examples verifies that the maximum relative error in the modeled sonic logs is lower than 3% for flexural, Stoneley, and compressional (P-) and shear (S-) modes. Compared to rigorous numerical simulations, the new fast sonic modeling method reduces computation time by 98%. Using the fast sonic simulation algorithm, we develop an inversion method that combines multi-frequency flexural dispersion and P- and S- mode slowness logs to estimate layer-by-layer compressional and shear slownesses of rock formations. Synthetic verification examples as well as interpretation of field cases indicate that the estimated formation compressional and shear slownesses are within 3% of true model properties, exhibiting a maximum uncertainty of 6%. When compared to conventional sonic-log interpretation, the new inversion-based method effectively reduces shoulder-bed effects and relative errors in estimated properties by 15%, while the vertical resolution of sonic logs is improved from 1.83 m to 0.5 m. Finally, we show that multi-mode wave interference in HA/HZ wells makes it difficult to identify the low-frequency slowness asymptote of the flexural mode. We extend the sensitivity method to three dimensions to approach this latter problem and to model high-frequency dispersion logs. Because the calculated P-mode slowness log exhibits strong dependence to processing parameters, conventional waveform semblance-based processing becomes inadequate in HA wells. We introduce a new P-arrival slowness log to circumvent wave mode interference and to avoid semblance calculations. Additionally, we also develop a one-dimensional integration method to rapidly model P-arrival slowness logs when HA/HZ wells penetrate anisotropic thin beds. The fast modeling algorithm generates synthetic logs that match sonic logs simulated with rigorous modeling procedures within 5% while providing a 99% reduction in computation time.

Modeling of Resistivity and Acoustic Borehole Logging Measurements Using Finite Element Methods

Download Modeling of Resistivity and Acoustic Borehole Logging Measurements Using Finite Element Methods PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 0128214651
Total Pages : 314 pages
Book Rating : 4.1/5 (282 download)

DOWNLOAD NOW!


Book Synopsis Modeling of Resistivity and Acoustic Borehole Logging Measurements Using Finite Element Methods by : David Pardo

Download or read book Modeling of Resistivity and Acoustic Borehole Logging Measurements Using Finite Element Methods written by David Pardo and published by Elsevier. This book was released on 2021-05-22 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling of Resistivity and Acoustic Borehole Logging Measurements Using Finite Element Methods provides a comprehensive review of different resistivity and sonic logging instruments used within the oil industry, along with precise and solid mathematical descriptions of the physical equations and corresponding FE formulations that govern these measurements. Additionally, the book emphasizes the main modeling considerations that one needs to incorporate into the simulations in order to obtain reliable and accurate results. Essentially, the formulations and methods described here can also be applied to simulate on-surface geophysical measurements such as seismic or marine controlled-source electromagnetic (CSEM) measurements. Simulation results obtained using FE methods are superior. FE methods employ a mathematical terminology based on FE spaces that facilitate the design of sophisticated formulations and implementations according to the specifics of each problem. This mathematical FE framework provides a highly accurate, robust, and flexible unified environment for the solution of multi-physics problems. Thus, readers will benefit from this resource by learning how to make a variety of logging simulations using a unified FE framework. Provides a complete and unified finite element approach to perform borehole sonic and electromagnetic simulations Includes the latest research in mathematical and implementation content on Finite Element simulations of borehole logging measurements Features a variety of unique simulations and numerical examples that allow the reader to easily learn the main features and limitations that appear when simulating borehole resistivity measurements

Numerical Simulation and Interpretation of Sonic Measurements in Vertical and Highly Deviated Wells

Download Numerical Simulation and Interpretation of Sonic Measurements in Vertical and Highly Deviated Wells PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 88 pages
Book Rating : 4.:/5 (962 download)

DOWNLOAD NOW!


Book Synopsis Numerical Simulation and Interpretation of Sonic Measurements in Vertical and Highly Deviated Wells by : Elsa Maalouf

Download or read book Numerical Simulation and Interpretation of Sonic Measurements in Vertical and Highly Deviated Wells written by Elsa Maalouf and published by . This book was released on 2016 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Borehole sonic measurements are widely used to estimate formation elastic properties and to construct synthetic seismograms. However, presence of noise compromises the accuracy of sonic logs. Sonic logs are prone to errors originating from near wellbore damage or mud-filtrate invasion. Moreover, sonic logs are calculated from the numerical processing of waveforms over a wide range of receivers. Numerical processing induces errors in the sonic slowness because the slowness value is averaged over the length of the receiver array. I apply a fast modeling method using spatial sensitivity functions to calculate sonic logs. First, I define the spatial sensitivity function for the compressional and flexural modes. Then, I apply the fast modeling in a joint inversion of shear and compressional slowness logs to mitigate noise contaminating sonic logs. Joint inversion is performed in vertical and slightly-dipping wells, to estimate layer-by-layer formation elastic and mechanical properties for isotropic and anisotropic formations. Finally, I introduce a fast modeling procedure for compressional and flexural modes in deviated and horizontal wells. Results of the fast modeling are compared to finite-difference numerical simulations. The fast modeling of sonic borehole measurements in deviated wells can be applied in a joint inversion to estimate formation elastic and geometrical properties.

Handbook of Borehole Acoustics and Rock Physics for Reservoir Characterization

Download Handbook of Borehole Acoustics and Rock Physics for Reservoir Characterization PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 012812332X
Total Pages : 486 pages
Book Rating : 4.1/5 (281 download)

DOWNLOAD NOW!


Book Synopsis Handbook of Borehole Acoustics and Rock Physics for Reservoir Characterization by : Vimal Saxena

Download or read book Handbook of Borehole Acoustics and Rock Physics for Reservoir Characterization written by Vimal Saxena and published by Elsevier. This book was released on 2018-04-28 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Borehole Acoustics and Rock Physics for Reservoir Characterization combines in a single useful handbook the multidisciplinary domains of the petroleum industry, including the fundamental concepts of rock physics, acoustic logging, waveform processing, and geophysical application modeling through graphical examples derived from field data. It includes results from core studies, together with graphics that validate and support the modeling process, and explores all possible facets of acoustic applications in reservoir evaluation for hydrocarbon exploration, development, and drilling support. The Handbook of Borehole Acoustics and Rock Physics for Reservoir Characterization serves as a technical guide and research reference for oil and gas professionals, scientists, and students in the multidisciplinary field of reservoir characterization through the use of petrosonics. It overviews the fundamentals of borehole acoustics and rock physics, with a focus on reservoir evaluation applications, explores current advancements through updated research, and identifies areas of future growth. Presents theory, application, and limitations of borehole acoustics and rock physics through field examples and case studies Features "Petrosonic Workflows" for various acoustic applications and evaluations, which can be easily adapted for practical reservoir modeling and interpretation Covers the potential advantages of acoustic-based techniques and summarizes key results for easy geophysical application

Numerical Simulation and Interpretation of Borehole Fluid-production Measurements

Download Numerical Simulation and Interpretation of Borehole Fluid-production Measurements PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 702 pages
Book Rating : 4.:/5 (89 download)

DOWNLOAD NOW!


Book Synopsis Numerical Simulation and Interpretation of Borehole Fluid-production Measurements by : Amir Frooqnia

Download or read book Numerical Simulation and Interpretation of Borehole Fluid-production Measurements written by Amir Frooqnia and published by . This book was released on 2014 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: Downhole production measurements are periodically acquired in hydrocarbon reservoirs to monitor and diagnose fluid movement in the borehole and the near-borehole region. However, because of the complexity involved with physical modeling and numerical implementation of borehole and formation multiphase flow behavior, inference of near-borehole petrophysical properties from production measurements is limited to simplified single-phase reservoir models. This dissertation develops a new transient coupled borehole-formation fluid flow algorithm to numerically simulate two-phase production logs (PL) acquired across heterogeneous rock formations penetrated by vertical and deviated boreholes. Subsequently, the coupled flow algorithm is used to estimate relevant dynamic petrophysical properties from borehole production measurements. The developed reservoir-borehole fluid flow model is based on an isothermal, one-dimensional (borehole axis) version of two-fluid formulation that simulates simultaneous flow of two fluid phases in oil-water, oil-gas, and gas-water flowing systems. Linkage of borehole and formation fluid flow models is carried out by introducing additional source terms into borehole mass conservation equations. Transient simulation of two-phase production measurements indicates the presence of borehole cross-flow when performing a shut-in test across differentially-depleted multilayer reservoirs. In a two-layer synthetic reservoir model penetrated by a vertical borehole, only two hours of through-the-borehole cross-communication of differentially-depleted layers gives rise to more than 14% increase in volume-averaged oil-phase relative permeability of the low-pressure layer. Simulated borehole fluid properties in the presence of cross-flow are used to estimate formation average pressure from two-phase selective-inflow-performance analysis. A new inversion-based interpretation algorithm is developed to estimate near-borehole absolute permeability and fluid-phase saturation from two-phase production logs. The inversion algorithm integrates production logs acquired in time-lapse mode to construct a near-borehole reservoir model that describes depth variations of skin factor over the elapsed time. Feasibility studies using synthetic reservoir models show that the estimated petrophysical properties are adversely influenced by the large volume of investigation associated with PL measurements. Moreover, undetectable fluid production across low-permeability layers decreases the sensitivity of production logs to layer incremental flow rate, thus increasing estimation uncertainty. Despite these limitations, the estimated fluid saturation and permeability across high-permeability layers are within 25% and 20% of the corresponding actual values, respectively. Oil-water and oil-gas flowing systems are additionally studied to quantify the added value of remedial workover operations (e.g., water and gas shut-off). Simulation of a gas shut-off performed in a gas-oil field example recommends a minimum bottom-hole pressure to prevent high gas production caused by (i) gas coning effects, and (ii) released gas from oil solution. Maintaining bottom-hole pressure above that limit gives rise to more than 60% reduction of downhole gas production.

New Methods for the Interpretation of Borehole Geophysical Measurements and Core Data Acquired in Spatially Complex Rocks

Download New Methods for the Interpretation of Borehole Geophysical Measurements and Core Data Acquired in Spatially Complex Rocks PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)

DOWNLOAD NOW!


Book Synopsis New Methods for the Interpretation of Borehole Geophysical Measurements and Core Data Acquired in Spatially Complex Rocks by : Mohamed Bennis

Download or read book New Methods for the Interpretation of Borehole Geophysical Measurements and Core Data Acquired in Spatially Complex Rocks written by Mohamed Bennis and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliable assessment of in situ storage and flow properties of rocks from borehole geophysical measurements and core data is crucial for appraising subsurface fluid resources. Well-log analysis in the presence of thin beds, mud-filtrate invasion, and/or electrical anisotropy remains a challenge in formation evaluation. Conventional interpretation methods rarely consider shoulder-bed effects on well logs, spatial distributions of fluid saturation around the borehole due to invasion, and differences in the volume of investigation of the different borehole instruments involved in the interpretation. This dissertation develops new quantitative methods for the interpretation of borehole geophysical measurements and core data acquired in spatially complex rocks. First, analytical and Bayesian methods are developed to assess horizontal and vertical resistivities from logging-while-drilling resistivity measurements in the presence of electrical anisotropy, noise, and well deviation effects. Borehole measurements (e.g., resistivity, density) are deconvolved into layer-by-layer physical properties with their associated uncertainty. Additionally, a new method is developed to calibrate and verify the reliability of core data and borehole measurements acquired under adverse geometrical conditions in formations with complex solid composition and thin beds. Numerical simulation of well logs based on high-resolution core data combined with rock typing and multi-well measurement analysis enable the detection of inconsistent, noisy, and inaccurate measurements, including cases of abnormal borehole environmental conditions causing biases in petrophysical interpretations. Finally, a new method is developed to quantify water saturation, residual hydrocarbon saturation, and permeability in the presence of deep mud-filtrate invasion, i.e., when the radial length of invasion is greater than the depth of investigation of borehole instruments. This method combines the numerical simulation of well logs with the physics of mud-filtrate invasion to quantify the effect of petrophysical properties and drilling conditions on nuclear and resistivity logs. Based on core-calibrated petrophysical models, thousands of invasion conditions were numerically simulated for a wide range of petrophysical properties and drilling conditions, including time of invasion and overbalance pressure. Then, analytical and machine-learning (ML) models were combined to infer unknown rock properties. Synthetic examples verify the accuracy and reliability of the introduced interpretation methods and quantify the uncertainty of estimated rock properties due to noisy measurements. Successful field applications are also documented for (a) the estimation of water saturation in an electrically anisotropic sandstone formation offshore Australia penetrated by high-angle and horizontal wells, (b) assessment of the quality of well logs acquired in a shaly-sandstone formation in the North Sea, and (c) estimation of water saturation, residual hydrocarbon saturation, and permeability in a tight-gas sandstone formation invaded with water-base mud in the Middle East. Comparison of interpretation results against those obtained using conventional petrophysical methods confirm the effectiveness of the new quantification techniques introduced in this dissertation for the quantification of petrophysical properties across a variety of rock formations

Mechanistic Numerical Simulation and Interpretation of Borehole Measurements of Spontaneous Electrical Potential Acquired in Complex Petrophysical Environments

Download Mechanistic Numerical Simulation and Interpretation of Borehole Measurements of Spontaneous Electrical Potential Acquired in Complex Petrophysical Environments PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 468 pages
Book Rating : 4.:/5 (128 download)

DOWNLOAD NOW!


Book Synopsis Mechanistic Numerical Simulation and Interpretation of Borehole Measurements of Spontaneous Electrical Potential Acquired in Complex Petrophysical Environments by : Joshua Christopher Bautista-Anguiano

Download or read book Mechanistic Numerical Simulation and Interpretation of Borehole Measurements of Spontaneous Electrical Potential Acquired in Complex Petrophysical Environments written by Joshua Christopher Bautista-Anguiano and published by . This book was released on 2021 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Borehole measurements of spontaneous electrical potential (SP) are routinely acquired in wells drilled with water-based mud. However, to this day, the interpretation of borehole SP measurements is chiefly limited to imprecise calculations of formation water resistivity and qualitative assessments of volumetric concentration of shale and permeability. This dissertation develops new methods to numerically simulate borehole SP measurements and improve their quantitative interpretation. Interpretation products are water saturation, water resistivity, and radius of invasion of mud-filtrate invasion in permeable rocks, together with their uncertainty. The calculation of formation water resistivity from borehole SP measurements is commonly performed via Nernst’s equation under the assumptions of shallow mud-filtrate invasion, negligible streaming potentials, and water as the only rock-saturating fluid. To circumvent these limitations while honoring the governing physics of coupled mass transport associated with SP phenomena, a three-dimensional finite-difference algorithm is developed to incorporate electrochemical, membrane, and electrokinetic SP phenomena in the simulation of borehole SP measurements. The algorithm implements a mechanistic description of non-equilibrium thermodynamics, which is coupled to a fluid-flow simulator to quantify the effects of time-varying conditions within permeable formations due to mud-filtrate invasion. Simulations indicate that the best spatial resolution of rock properties possible with SP borehole measurements occurs when rock beds are perpendicular to the well; deviated wells or dipping beds give rise to extended and pronounced shoulder-bed effects on SP measurements. It is also found that the simplifying assumption of perpendicular beds relative to the borehole does not cause significant errors in the numerical simulation of borehole SP measurements acquired in well trajectories with a relative dip less than 30°, thereby reducing CPU time by a factor of at least 1.76. Furthermore, electrokinetic effects on SP measurements become negligible for commonly used pressure overbalance ranges. For the interpretation of borehole SP measurements acquired in hydrocarbon-bearing rocks, this dissertation explores whether the difference between borehole SP measurements and Nernst-equation predictions enables the estimation of in situ hydrocarbon saturation of porous rocks. A new petrophysical model is advanced and successfully verified to establish the limits of detectability of hydrocarbon saturation solely from borehole SP measurements. It is found that optimal conditions for the quantification of hydrocarbon saturation from borehole SP measurements take place when (1) capillary forces dominate the process of mud-filtrate invasion, (2) the matrix-pore interface region, known as the electrical double layer, has a relevant impact on the diffusion of counter-ions, and (3) the electrolyte concentration of drilling mud is greater than that of formation water. Three blind tests show that the developed petrophysical model and the mechanistic SP simulation algorithm enable the estimation of hydrocarbon saturation from SP borehole measurements without the need of electrical resistivity measurements or porosity calculations. The estimation is reliable when (a) the volumetric concentration of shale is negligible, (b) the pore network structure is constant throughout the reservoir, and (c) radial invasion profiles are similar to those observed in calibration key wells used to adjust the parameters of the new petrophysical model. Finally, this dissertation develops a new inversion-based method for the interpretation of borehole SP measurements, which concomitantly mitigates shoulder-bed and mud-filtrate invasion effects on SP logs via fast numerical simulations based on Green’s functions. The method delivers layer-by-layer estimates of (a) equivalent NaCl concentration, (b) radius of mud-filtrate invasion, and (c) sodium macroscopic transport number, together with their uncertainty, by progressively matching borehole SP measurements with their numerical simulations. Successful examples of implementation include noisy borehole SP measurements acquired in aquifers with various degrees of petrophysical complexity. Results confirm the possibility of accurately and reliably estimating the electrical resistivity of formation water resistivity solely from borehole SP measurements, i.e., without the need of porosity calculations or fitting parameters from independent core measurements (as is the case with borehole resistivity measurements). Inversion-based interpretation results (a) compare well to those obtained from resistivity and nuclear porosity logs, (b) provide estimates of uncertainty, and (c) can assimilate a priori knowledge of aquifer petrophysical properties in the estimation

Petrophysics

Download Petrophysics PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 488 pages
Book Rating : 4.F/5 ( download)

DOWNLOAD NOW!


Book Synopsis Petrophysics by :

Download or read book Petrophysics written by and published by . This book was released on 2003 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Interpretation of Borehole Measurements Acquired in Laminated Clastic Sequences Subject to Mud Filtrate Invasion

Download Interpretation of Borehole Measurements Acquired in Laminated Clastic Sequences Subject to Mud Filtrate Invasion PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 150 pages
Book Rating : 4.:/5 (852 download)

DOWNLOAD NOW!


Book Synopsis Interpretation of Borehole Measurements Acquired in Laminated Clastic Sequences Subject to Mud Filtrate Invasion by : Subhadeep Chowdhury

Download or read book Interpretation of Borehole Measurements Acquired in Laminated Clastic Sequences Subject to Mud Filtrate Invasion written by Subhadeep Chowdhury and published by . This book was released on 2004 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Simulation and Inversion of Borehole Electromagnetic Measurements for the Estimation of Petrophysical Properties in the Presence of Mud-filtrate Invasion

Download Simulation and Inversion of Borehole Electromagnetic Measurements for the Estimation of Petrophysical Properties in the Presence of Mud-filtrate Invasion PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 526 pages
Book Rating : 4.:/5 (852 download)

DOWNLOAD NOW!


Book Synopsis Simulation and Inversion of Borehole Electromagnetic Measurements for the Estimation of Petrophysical Properties in the Presence of Mud-filtrate Invasion by : Jesús Mauricio Salazar Luna

Download or read book Simulation and Inversion of Borehole Electromagnetic Measurements for the Estimation of Petrophysical Properties in the Presence of Mud-filtrate Invasion written by Jesús Mauricio Salazar Luna and published by . This book was released on 2008 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic, electromagnetic (EM), and nuclear open-hole measurements are affected by fluids saturating near-wellbore porous and permeable rock formations, including hydrocarbons, water, and mud filtrate. Fluid invasion effects can be quantified and advantageously used to estimate petrophysical properties of the invaded rock formations. This dissertation incorporates the physics of water-base mud- (WBM) and oil-base mud- (OBM) filtrate invasion to the simulation and inversion of borehole EM measurements. We assume vertical boreholes penetrating clastic hydrocarbon- or water-bearing formations subject to either WBM- or OBM-filtrate invasion. The simulation of EM measurements in the presence of mud-filtrate invasion considers three different approaches: (1) piston-like invasion profiles, where we solely consider invaded- (flushed) and virgin- (uncontaminated) zones, (2) two-phase immiscible displacement and salt mixing between the invading WBM filtrate and connate water, and (3) invasion of single or multi-component OBM-filtrate into a formation saturated with multiple hydrocarbon components wherein the individual components are first-contact miscible. The last two approaches honor the physics of mudcake growth as well as the petrophysical properties that govern the process of multi-phase, multi-component fluid-flow displacement and include the presence of irreducible, capillary-bound and movable water. Electromagnetic measurements are simulated from spatial distributions of electrical resistivity calculated from the simulations of mud-filtrate invasion using clean- or shaly-sand water-saturationresistivity models. Inversion of petrophysical properties is posed as the nonlinear minimization of quadratic objective functions that quantify the misfit between EM measurements and their simulations. In the case of WBM piston-like invasion profiles in water-bearing formations, combined inversion of array-induction resistivity and spontaneous potential (SP) measurements yields connate water electrical resistivity and Archie's cementation exponent. Permeability is calculated from the inversion of array-induction resistivity measurements assuming immiscible fluid-flow displacement of WBM into hydrocarbonbearing formations. Accurate reconstructions of layer-by-layer permeability are primarily constrained by the availability of a-priori information about time of invasion, rate of mud-filtrate invasion, overbalance pressure, capillary pressure, and relative permeability. This dissertation also quantifies the influence of petrophysical and fluid properties on borehole resistivity measurements acquired in the presence of compositional mixing of OBM filtrate invading partially hydrocarbon-saturated rock formations. Numerical simulations of OBM-filtrate invasion are performed with an adaptive-implicit compositional formulation that allows one to quantify the effects of additional components of mud-filtrate and native fluids on EM measurements. Perturbations of petrophysical and fluid properties enable the quantification of rock wettability changes due to OBM-filtrate invasion and their effect on the simulated induction resistivity measurements. Finally, simulations of induction resistivity measurements in the presence of OBM are compared to the corresponding measurements in the presence of WBMfiltrate invasion. The latter analysis allows us to estimate a realistic flow rate of OBMfiltrate invasion that is responsible for the variation of induction resistivity measurements as a function of their radial length of response. The combined simulation of the physics of mud-filtrate invasion and EM measurements provides reliable estimates of true formation resistivity and hence of water saturation, thereby improving the assessment of in-place hydrocarbons reserves.

Quantitative Analysis of Muli-component Borehole Electromagnetic Induction Responses Using Anisotropic Forward Modeling and Inversion

Download Quantitative Analysis of Muli-component Borehole Electromagnetic Induction Responses Using Anisotropic Forward Modeling and Inversion PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 236 pages
Book Rating : 4.:/5 (89 download)

DOWNLOAD NOW!


Book Synopsis Quantitative Analysis of Muli-component Borehole Electromagnetic Induction Responses Using Anisotropic Forward Modeling and Inversion by : Michael John Batiste Tompkins

Download or read book Quantitative Analysis of Muli-component Borehole Electromagnetic Induction Responses Using Anisotropic Forward Modeling and Inversion written by Michael John Batiste Tompkins and published by . This book was released on 2003 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Expanded Abstracts with Biographies

Download Expanded Abstracts with Biographies PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 1094 pages
Book Rating : 4.F/5 ( download)

DOWNLOAD NOW!


Book Synopsis Expanded Abstracts with Biographies by :

Download or read book Expanded Abstracts with Biographies written by and published by . This book was released on 1999 with total page 1094 pages. Available in PDF, EPUB and Kindle. Book excerpt: