The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Thomas Alwin Blasingame - One of the best experts on this subject based on the ideXlab platform.
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Flow of Non-Newtonian Fluids within a Double Porosity Reservoir under Pseudosteady State Interporosity Transfer Conditions
Day 1 Wed May 17 2017, 2017Co-Authors: J. R. Garcia-pastrana, Alex R. Valdes-perez, Thomas Alwin BlasingameAbstract:Abstract Non-Newtonian fluids have been characterized over the decades, and such characterizations may be used to model a new approach in engineering disciplines. Non-Newtonian fluids are classified as non-time dependent and time-dependent fluids. This paper focuses on the non-time dependent classification, specifically pseudoplastic fluids. The ranges in these fluids allow the proposed model to be validated. The new reservoir model accounts for non-Newtonian behavior within a double-porosity reservoir. This model demonstrates an interporosity transfer function for Pseudosteady state, based on a new parameter: dimensionless matrix contribution (D). This parameter differentiates our method from previous efforts based on the Pseudosteady state interporosity flow for Newtonian fluids introduced in the 1960's. We derive the partial differential equation for a non-Newtonian flow within a double porosity reservoir under Pseudosteady state interporosity transfer conditions. The solution presented is for an infinite acting reservoir (assuming the corresponding initial, inner and outer conditions). The objective of this paper is to deliver and provide tools that may help to characterize double porosity reservoir under the condition that a non-Newtonian fluid is present, and the interporosity transfer conditions between a matrix system and a fracture system are in Pseudosteady-state.
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Analysis and Interpretation of Water-Oil-Ratio Performance
2002Co-Authors: V. V. Bondar, Thomas Alwin BlasingameAbstract:This work presents the development and validation of a multivariate relation for the behavior of the water-oil-ratio (WOR) and/or water cut (fw) functions. This new model incorporates the reservoir and fluid properties for both phases (oil and water) and is based on the assumption of Pseudosteady-state flow conditions. This work is an extension of traditional (i.e., steady-state) methods for the ca se of Pseudosteady-state flow — for both the oil and water phases. In this work, our Pseudosteady-state model reproduces observed field p erformance substantially better than any of the steady-state models. We propose that this approach can be applied to any reservoir system undergoing waterflood. The specific tasks achieved in this work include: 1. Development of a rigorous model for the simultaneous flow of oil and water during Pseudosteady-state flow conditions. This model has been validated using several field cases and gives an excellent representation of the WOR (or fw) data trend(s).
Marius Turnea - One of the best experts on this subject based on the ideXlab platform.
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Study of the influence of solute and carrier characteristics on facilitated pertraction mechanism in Pseudosteady-state conditions
Journal of Membrane Science, 2008Co-Authors: Dan Cascaval, A.-i. Galaction, Marius TurneaAbstract:Abstract Facilitated pertraction of p-aminobenzoic acid (PABA) and p-hydroxybenzoic acid (PHBA) with Amberlite LA-2 and di-(2-ethylhexyl)phosphoric acid (D2EHPA) in Pseudosteady-state mode have been comparatively analyzed. The experiments have been carried out using an U-shaped pertraction cell which allowed to easily maintaining the liquid membrane between the two aqueous phases. On the basis of the theoretical investigation, a model describing the solute accumulation inside the liquid membrane by means of the permeability factor has been developed. The proposed model offers a good concordance with the experimental data and can be useful for facilitated pertraction optimization.
Jalilian Milad - One of the best experts on this subject based on the ideXlab platform.
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Application of the transient rate decline analysis for determining average reservoir pressure in naturally fractured reservoirs
Petroleum Exploration and Development, 2015Co-Authors: Daryasafar Amin, Amareh Iman, Fathinasab Mohammad, Kharrat Riyaz, Jalilian MiladAbstract:Abstract Based on the fracture-pore dual medium model proposed by Warren and Root et al, the solution of the Pseudosteady-constant production fractured system by Mavor and Cinco-Ley and the solution of the Pseudosteady-constant pressure matrix system by Daprat are extended, and a new method is presented for estimating average reservoir pressure of naturally fractured reservoirs using the transient rate decline analysis. The specific method is taking logarithm of the matrix production equation and fracture production equation to obtain two straight lines; then the slope and intercept of the straight lines are used to determine storage capacity ratio, total storage capacity and reservoir drainage area, and average reservoir pressure at last. Examples show that the new method is easy and practical, and gives result similar to that of the material balance method and direct Tiab synthesis method.
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Application of the transient rate decline analysis for determining average reservoir pressure in naturally fractured reservoirs
KeAi Communications Co. Ltd., 2015Co-Authors: Daryasafar Amin, Amareh Iman, Fathinasab Mohammad, Kharrat Riyaz, Jalilian MiladAbstract:Based on the fracture-pore dual medium model proposed by Warren and Root et al, the solution of the Pseudosteady-constant production fractured system by Mavor and Cinco-Ley and the solution of the Pseudosteady-constant pressure matrix system by Daprat are extended, and a new method is presented for estimating average reservoir pressure of naturally fractured reservoirs using the transient rate decline analysis. The specific method is taking logarithm of the matrix production equation and fracture production equation to obtain two straight lines; then the slope and intercept of the straight lines are used to determine storage capacity ratio, total storage capacity and reservoir drainage area, and average reservoir pressure at last. Examples show that the new method is easy and practical, and gives result similar to that of the material balance method and direct Tiab synthesis method. Key words: naturally fractured reservoir, average reservoir pressure, pressure transient testing, decline curve analysis, dual medium, pseudo-steady state flo
Kun Sang Lee - One of the best experts on this subject based on the ideXlab platform.
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Applicability of a Succession-of-Pseudosteady-States Approach on the Modeling of Depleting Gas Reservoirs
Energy Sources Part A: Recovery Utilization and Environmental Effects, 2009Co-Authors: Kun Sang LeeAbstract:Abstract The succession-of-Pseudosteady-states approach, originally established for linear flow problems, has been extended to calculate the long-time behavior of real gas flow in a closed reservoir. To extend the approach, a linearized form of gas diffusivity equation was derived in terms of normalized pseudovariables. The applicability and limitations of the approach were examined through error analysis on the results from a series of numerical simulation works under various reservoir and operational parameters including permeability, pressure, flowrate, and gas properties. For most cases, a fairly good agreement was observed between the predictions from the Pseudosteady-states model and conventional reservoir simulation. The accuracy depends weakly on the flowrate, and is almost independent of specific gravity. Except for the cases of very low permeabilities, however, computations indicate that neglecting infinite-acting flow behavior does not introduce significant error in the procedure. The validity ...
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modified Pseudosteady state approach to calculate long time performance of closed gas reservoirs
Journal of the Korean Institute of Gas, 1998Co-Authors: Kun Sang LeeAbstract:This paper considers the applicability of a Pseudosteady-state approach to the long-time behavior of real gas flow in a closed reservoir. The method involves a combination of a linearized gas diffusivity equation using a normalized pseudotime and a material balance equation. For the simulation of field-scale problems with multiple wells of differing production rates over extended production periods, the Pseudosteady-state equation was solved successively for each flow period. Results from this study show that the approach provides a fast and accurate method for modeling the long-time behavior of gas reservoirs under depletion conditions.
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Succession-of-States Model for Calculating Long-Time Performance of Depletion Reservoirs
SPE Journal, 1998Co-Authors: Kun Sang Lee, Mark A. Miller, Kamy SepehrnooriAbstract:This paper (SPE 51023) was revised for publication from paper SPE 37030, first presented at the 1996 SPE Asia Pacific Oil & Gas Conference held in Adelaide, Australia, 28-31 October. Original manuscript received for review 16 September 1996. Revised manuscript received 20 May 1998. Revised manuscript approved 9 June 1998. Summary This study presents a new finite-element approach for directly calculating Pseudosteady-state flow behavior for wells in depletion systems. The approach allows for spatially dependent reservoir properties, complex reservoir geometries, and multiple wells. Results are verified against long-time transient solutions reported in the literature for several regularly shaped systems. The paper also demonstrates application of the approach to field-scale problems. Results show that this approach provides a fast and accurate method for modeling the long-time behavior of depletion reservoirs. The approach is particularly applicable to single-phase volumetric gas reservoirs. A bound reservoir with wells producing at constant rate will exhibit Pseudosteady-state behavior after the end of typically short-lived infinite-acting and transition flow periods. This study develops a new approach for directly calculating Pseudosteady-state flow behavior without solving the full time-dependent form of the diffusivity equation. This approach can be applied to the linearized forms of the diffusivity equation for either single-phase liquid or gas flow. A finite-element method is used that allows for spatially dependent reservoir properties, complex reservoir geometries, and multiple wells. The first part of this paper presents a verification of the approach by comparing results for some regularly shaped systems against full-transient solutions reported in the literature. For the simulation of field-scale problems with multiple wells of differing production rates, a well model based on a near-wellbore approximation of the pseudo pressure distribution during Pseudosteady-state is introduced to reduce the concentration of elements near wells. The second part of the paper demonstrates application of the direct Pseudosteady-state concept to actual reservoir problems. To account for rate changes during extended production periods, the Pseudosteady-state equation was solved successively for each flow period and combined with an overall reservoir material balance analysis. Results from this study show that this approach provides a fast and accurate method for modeling the long-time behavior of various types of reservoirs under depletion conditions. The approach is particularly applicable to single-phase volumetric gas reservoirs. P. 279
K Scheffler - One of the best experts on this subject based on the ideXlab platform.
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calculation of flip angles for echo trains with predefined amplitudes with the extended phase graph epg algorithm principles and applications to hyperecho and traps sequences
Magnetic Resonance in Medicine, 2004Co-Authors: Juergen Hennig, Matthias Weigel, K SchefflerAbstract:The article presents an algorithm for calculation of flip angles in multiecho experiments to generate echoes with predefined amplitudes based on the extended phase graph algorithm. The algorithm can be used to optimize the echo envelope and thus the point spread function (PSF) in hyperecho and TRAPS (transition into the Pseudosteady state) experiments while minimizing the total RF power. Implementations at 3 T using echo trains with Gaussian and Lorentzian PSF demonstrate a reduction in RF power by a factor of 3–5 while maintaining high image quality. Magn Reson Med 51:68–80, 2004. © 2003 Wiley-Liss, Inc.
