Author: Obinna Onyinye Duru
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 399
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Book Description
Acquisition of downhole temperature measurements, in addition to production data, is routine in production systems. The temperature measurements, which are currently being used for pressure data correction, are cheap to acquire, accurate and have good resolutions. The answer to the question of how useful these temperature measurements can be, beyond the current utilization for pressure correction, was the goal of this research work. In the first part of this work, a mechanistic multiphysics and multiscale model for thermal transport process in a porous medium was developed, accounting for compressibility and viscous dissipation effects like Joule-Thomson and adiabatic expansion phenomena. To validate the model, a laboratory experiment was designed to allow for a controlled flow of air through a porous core, while measuring the temperature changes at different locations. The data acquired were used to verify the model and perform sensitivity studies, and the results showed functional dependencies of the model on useful reservoir parameters such as porosity, flow velocities and thermal properties of the rock and fluid; and these functional dependencies revealed the potential of temperature data as an additional source of constraining data in temporal and distributed reservoir parameter estimation. In addition, the temperature model was well suited for the application of a number of analytical tools that lead to the extraction of these useful reservoir characteristic information. In the second part, using multiresolution methods based on the second derivative of the Gaussian kernel, temperature measurements were combined with pressure data to improve the identification of transients in data as well as yield better behavioral filtering. Until now, only pressure measurements are used and this has shown to be unreliable. The approach developed here exploited the independence between the pressure and temperature measurements to constrain the estimation of the location of the breakpoints. The third segment of this research exploited the convective nature of thermal transport during flow to characterize near wellbore properties such as the extent of damage around a well (or extent of stimulation). The model lent itself to the application of the semianalytical Operator Splitting decomposition technique and as a result, the solution of the advection component could be separated and used to estimate near-wellbore structures such as damage or stimulation radius and permeability. As temperature measurements are an independent source of measurements, a joint inversion of production data and temporal temperature measurements, taken from multiwell production systems, showed a significant improvement in the reservoir state estimation problem, using state space estimation techniques like the Ensemble Kalman filter. This marked improvement was over the results from current approaches which match only production data. Results showed that introducing temperature improved the resolution of both permeability and porosity fields significantly. The last part of this research dealt with the estimation of flowrate, using only temperature measurements. The temperature model showed a strong functional dependence of temperature on flowrates at high Peclet number. By deconvolution, the advective flow kernel was separated from the diffusion part, and the complete flowrate history reconstructed from this kernel. Results showed that in synthetic and field cases, this extracted flowrate compared well with the true flowrate measurements. The philosophical significance of this work is that low-cost temperature measurements, which are measured routinely in producing wells, are a promising source of additional data for further constraining of reservoir characterization and optimization problems.
Author: Obinna Onyinye Duru
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
Acquisition of downhole temperature measurements, in addition to production data, is routine in production systems. The temperature measurements, which are currently being used for pressure data correction, are cheap to acquire, accurate and have good resolutions. The answer to the question of how useful these temperature measurements can be, beyond the current utilization for pressure correction, was the goal of this research work. In the first part of this work, a mechanistic multiphysics and multiscale model for thermal transport process in a porous medium was developed, accounting for compressibility and viscous dissipation effects like Joule-Thomson and adiabatic expansion phenomena. To validate the model, a laboratory experiment was designed to allow for a controlled flow of air through a porous core, while measuring the temperature changes at different locations. The data acquired were used to verify the model and perform sensitivity studies, and the results showed functional dependencies of the model on useful reservoir parameters such as porosity, flow velocities and thermal properties of the rock and fluid; and these functional dependencies revealed the potential of temperature data as an additional source of constraining data in temporal and distributed reservoir parameter estimation. In addition, the temperature model was well suited for the application of a number of analytical tools that lead to the extraction of these useful reservoir characteristic information. In the second part, using multiresolution methods based on the second derivative of the Gaussian kernel, temperature measurements were combined with pressure data to improve the identification of transients in data as well as yield better behavioral filtering. Until now, only pressure measurements are used and this has shown to be unreliable. The approach developed here exploited the independence between the pressure and temperature measurements to constrain the estimation of the location of the breakpoints. The third segment of this research exploited the convective nature of thermal transport during flow to characterize near wellbore properties such as the extent of damage around a well (or extent of stimulation). The model lent itself to the application of the semianalytical Operator Splitting decomposition technique and as a result, the solution of the advection component could be separated and used to estimate near-wellbore structures such as damage or stimulation radius and permeability. As temperature measurements are an independent source of measurements, a joint inversion of production data and temporal temperature measurements, taken from multiwell production systems, showed a significant improvement in the reservoir state estimation problem, using state space estimation techniques like the Ensemble Kalman filter. This marked improvement was over the results from current approaches which match only production data. Results showed that introducing temperature improved the resolution of both permeability and porosity fields significantly. The last part of this research dealt with the estimation of flowrate, using only temperature measurements. The temperature model showed a strong functional dependence of temperature on flowrates at high Peclet number. By deconvolution, the advective flow kernel was separated from the diffusion part, and the complete flowrate history reconstructed from this kernel. Results showed that in synthetic and field cases, this extracted flowrate compared well with the true flowrate measurements. The philosophical significance of this work is that low-cost temperature measurements, which are measured routinely in producing wells, are a promising source of additional data for further constraining of reservoir characterization and optimization problems.
Author: Jorge Luis Landa
Publisher:
ISBN:
Category : Oil reservoir engineering
Languages : en
Pages : 502
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Book Description
Author: Abhiniandhan Raghu
Publisher:
ISBN:
Category : Ecological heterogeneity
Languages : en
Pages : 126
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Book Description
The high heterogeneity of petroleum reservoirs, represented by their spatially varying rock properties (porosity and permeability), greatly dictates the quantity of recoverable oil. In this work, the estimation of these rock properties, which is crucial for the future performance prediction of a reservoir, is carried out through a history matching technique using constrained ensemble Kalman filtering (EnKF) and particle filtering (PF) methods. The first part of the thesis addresses some of the main limitations of the conventional EnKF. The EnKF, formulated on the grounds of Monte Carlo sampling and the Kalman filter (KF), arrives at estimates of parameters based on statistical analysis and hence could potentially yield reservoir parameter estimates that are not geologically realistic and consistent. In order to overcome this limitation, hard and soft data constraints in the recursive EnKF estimation methodology are incorporated. Hard data refers to the actual values of the reservoir parameters at discrete locations obtained by core sampling and well logging. On the other hand, the soft data considered here is obtained from the variogram, which characterize the spatial correlation of the rock properties in a reservoir. In this algorithm, the correlation matrix obtained after the unconstrained EnKF update is transformed to honour the true correlation structure from the variogram by applying a scaling and projection method. This thesis also deals with the problem of spurious correlation induced by the Kalman gain computations in the EnKF update step, potentially leading to erroneous update of parameters. In order to solve this issue, a covariance localization-based EnKF coupled with geostatistics is implemented in reservoir history matching. These algorithms are implemented on two synthetic reservoir models and their efficacy in yielding estimates consistent with the geostatistics is observed. It is found that the computational time involved in the localization-based EnKF framework for reservoir history matching is considerably reduced owing to the reduction in the size of the parameter space in the EnKF update step. Also, the geostatistics-based covariance localization performs better in capturing the spatial heterogeneity and variability of the reservoir permeability than the traditional methods. In the second part of the thesis, we extend the history matching implementation using the particle filtering. Reservoir models, being nonlinear, the distributions of the noise and parameters are generally non-Gaussian in nature. Since the EnKF may fail to obtain accurate estimates when the distributions involved in the model are non-Gaussian, we attempt to use a completely Bayesian filter, the particle filter, to estimate reservoir parameters. In addition, the geostatistics-based covariance localization is also coupled with the particle filter and is found to perform better than the filter without any localization.
Author: Hedong Sun
Publisher: Gulf Professional Publishing
ISBN: 0128026278
Category : Technology & Engineering
Languages : en
Pages : 352
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Book Description
In recent years, production decline-curve analysis has become the most widely used tool in the industry for oil and gas reservoir production analysis. However, most curve analysis is done by computer today, promoting a "black-box" approach to engineering and leaving engineers with little background in the fundamentals of decline analysis. Advanced Production Decline Analysis and Application starts from the basic concept of advanced production decline analysis, and thoroughly discusses several decline methods, such as Arps, Fetkovich, Blasingame, Agarwal-Gardner, NPI, transient, long linear flow, and FMB. A practical systematic introduction to each method helps the reservoir engineer understand the physical and mathematical models, solve the type curves and match up analysis, analyze the processes and examples, and reconstruct all the examples by hand, giving way to master the fundamentals behind the software. An appendix explains the nomenclature and major equations, and as an added bonus, online computer programs are available for download. - Understand the most comprehensive and current list of decline methods, including Arps, Fetkovich, Blasingame, and Agarwal-Gardner - Gain expert knowledge with principles, processes, real-world cases and field examples - Includes online downloadable computer programs on Blasingame decline type curves and normalized pseudo-pressure of gas wells
Author: Hedong Sun
Publisher: Gulf Professional Publishing
ISBN: 0128183241
Category : Science
Languages : en
Pages : 368
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Book Description
Thanks to technology, fractured carbonate gas reservoirs are becoming more discoverable, but because these assets are more complex and diverse, there is a high level of difficulty in understanding how to plan design and performance analysis. Dynamic Description Technology of Fractured Vuggy Gas Reservoirs delivers a critical reference to reservoir and production engineers on all the basic characteristics of fractured vuggy gas reservoirs and combines both static and dynamic data to improve the reservoir characterization accuracy and development. Based on the full life cycle of well testing and advanced production decline analysis, this reference also details how to apply reservoir dynamic evaluation, reserve estimation, and performance forecasting. Offering one collective location for the latest research on fractured gas reservoirs, the reference also covers: Physical models, analysis examples, and processes 3D numerical well test analysis technology Deconvolution technology of production decline analysis Packed with many calculation examples and more than 100 case studies, Dynamic Description Technology of Fractured Vuggy Gas Reservoirs gives engineers a strong tool to further exploit these complex assets. Gain advanced knowledge in well test and production decline analysis as well as performance forecasting specific to fractured vuggy carbonate gas reservoirs Understand the characteristics, advantages, disadvantages, and current limitations in technology of fractured vuggy carbonate gas reservoirs Bridge from theory to practice by combining static and dynamic data to form more accurate real-world analysis and modelling
Author: Geothermal Resources Council
Publisher:
ISBN:
Category : Nature
Languages : en
Pages : 666
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Book Description
Author: Fikri J. Kuchuk
Publisher: Elsevier Science
ISBN: 9780444529534
Category : Technology & Engineering
Languages : en
Pages : 414
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Book Description
This reference presents a comprehensive description of flow through porous media and solutions to pressure diffusion problems in homogenous, layered, and heterogeneous reservoirs. It covers the fundamentals of interpretation techniques for formation tester pressure gradients, and pretests, multiprobe and packer pressure transient tests, including derivative, convolution, and pressure-rate and pressure-pressure deconvolution. Emphasis is placed on the maximum likelihood method that enables one to estimate error variances in pressure data along with the unknown formation parameters. Serves as a training manual for geologists, petrophysicists, and reservoir engineers on formation and pressure transient testing Offers interpretation techniques for immediate application in the field Provides detailed coverage of pretests, multiprobe and packer pressure transient tests, including derivative, convolution, and pressure-rate and pressure-pressure deconvolution
Author: Pengbo Lu
Publisher:
ISBN:
Category :
Languages : en
Pages : 205
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Book Description
Author: Charles Robert Smith
Publisher: Ogci Publications
ISBN:
Category : Science
Languages : en
Pages : 488
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Book Description
