scholarly journals An Extensive Study on Desorption Models Generated Based on Langmuir and Knudsen Diffusion

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6435
Author(s):  
Hamda Alkuwaiti ◽  
Hadi Belhaj ◽  
Mohammed Aldhuhoori ◽  
Bisweswar Ghosh ◽  
Ryan Fernandes

Although gas desorption is a known phenomenon, modeling fluid flow in tight gas reservoirs often ignores the governing desorption effect, assuming that viscous transport is the predominant controller, resulting in an erroneous prediction of mass transport and fluid flow calculations. Thus, developing a new model accommodating all the major contributing forces in such a medium is essential. This work introduces a new comprehensive flow model suitable for tight unconventional reservoirs, including viscous, inertia, diffusion, and sorption forces, to account for fluid transport. Based on Langmuir law and Knudsen diffusion effect, three models were generated and compared with different known models using synthetic data. The model was solved and analyzed for different scenario cases, and parametric studies were conducted to evaluate the desorption effect on different reservoir types using MATLAB. Results show that the contribution of the sorption mechanism to the flow increases with the reducing permeability of the medium and lower viscosity of the flowing fluid and an additional pressure drop up to 10 psi was quantified.

2021 ◽  
Author(s):  
Mohammed Aldhuhoori ◽  
Hadi Belhaj ◽  
Bisweswar Ghosh ◽  
Ryan Fernandes ◽  
Hamda Alkuwaiti ◽  
...  

Abstract A model for single-phase fluid flow in tight UCRs was previously produced by modifying the flow Forchheimer’s equation. The new modification addresses the fluid transport phenomena into three scales incorporating a diffusion term. In this study, a new liner model, numerically solved, has been developed and deployed for a gas huff and puff project. The new model has been numerically validated and verified using synthetic data and huff and puff case study. Ideally, the new model suits fluid flow in tight UCRs. The modified Forchheimer’s model presented is solved using the MATLAB numerical method for linear multiphase flow. For the huff & puff case, very simple profiles and flow dynamics of the main flow parameters have been established and a thorough parametric analysis and verifications were performed. It has been observed that the diffusion system becomes more prominent in regulating flow velocity with low permeability of the formation rock and low viscosity of the flowing fluid. The findings indicate a behavioral alignment with a previous hypothesis that matches actual reservoir behavior.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manzar Fawad ◽  
Nazmul Haque Mondol

AbstractGeological CO2 storage can be employed to reduce greenhouse gas emissions to the atmosphere. Depleted oil and gas reservoirs, deep saline aquifers, and coal beds are considered to be viable subsurface CO2 storage options. Remote monitoring is essential for observing CO2 plume migration and potential leak detection during and after injection. Leak detection is probably the main risk, though overall monitoring for the plume boundaries and verification of stored volumes are also necessary. There are many effective remote CO2 monitoring techniques with various benefits and limitations. We suggest a new approach using a combination of repeated seismic and electromagnetic surveys to delineate CO2 plume and estimate the gas saturation in a saline reservoir during the lifetime of a storage site. This study deals with the CO2 plume delineation and saturation estimation using a combination of seismic and electromagnetic or controlled-source electromagnetic (EM/CSEM) synthetic data. We assumed two scenarios over a period of 40 years; Case 1 was modeled assuming both seismic and EM repeated surveys were acquired, whereas, in Case 2, repeated EM surveys were taken with only before injection (baseline) 3D seismic data available. Our results show that monitoring the CO2 plume in terms of extent and saturation is possible both by (i) using a repeated seismic and electromagnetic, and (ii) using a baseline seismic in combination with repeated electromagnetic data. Due to the nature of the seismic and EM techniques, spatial coverage from the reservoir's base to the surface makes it possible to detect the CO2 plume’s lateral and vertical migration. However, the CSEM low resolution and depth uncertainties are some limitations that need consideration. These results also have implications for monitoring oil production—especially with water flooding, hydrocarbon exploration, and freshwater aquifer identification.


IAWA Journal ◽  
1985 ◽  
Vol 6 (4) ◽  
pp. 303-307 ◽  
Author(s):  
George S. Ellmore ◽  
Frank W. Ewers

The notion that most xylem transport in stems of ring-porous trees occurs in the outermost growth ring requires experimental support. Significance of this ring is challenged by workers who find tracer dyes appearing in 4 to 8 growth rings rather than in only the outermost increment. We test the hypothesis that the outermost growth ring is of overriding significance in fluid transport through stems of Ulmus, a ring-porous tree. Fluid flow through the outermost ring was quantified by removing that ring, calculating gravity flow rates (hydraulic conductivity at 10.13 kPa m-1 ), and by tracing the transport pathway through control and experimental stem segments. From measurements corroborating theoretical calculations based on Poiseuille's law, over 90% of fluid flow through the stem occurs through the outermost ring. Remaining rings combine to account for less than 10% of xylem transport. As a result of dependence upon transport in the most superficial xylem, ring-porous trees such as elm, oak, ash, and chestnut are particularly susceptible to xylem pathogens entering from the bark.


Author(s):  
Anna Jensen ◽  
Michael G. Schrlau

Arrays of carbon nanotubes (CNTs) have shown significant promise for delivering biomolecules into cells with high efficiency and low toxicity. In these applications, biomolecules are flowed from a large fluid reservoir, through the lumens of vertically-aligned, open-ended CNTs, and into cells cultured over top of the CNTs on the other side. Over the course of several transfection experiments, it was discovered that biomolecule delivery varied considerably depending on the type of biomolecule being delivered. It was also inferred that the number of CNTs the cells covered would affect the transfection rate. In this work, an experiment was designed and conducted to visually characterize fluid flow through these CNT arrays and other nanoporous membranes. The experiment utilizes a 3D printed flow device consisting of anodized alumina oxide (AAO) membranes and restricts flow to a predefined circular area. Flow data was taken by measuring the intensity of fluorescent dye as it diffused through the AAO membrane. The intensity measurements were then plotted as a function of time from which diffusion times constants were calculated. This work establishes a platform technique for visualizing fluid transport through AAO membranes, which can be applied to CNT arrays, and allow for the testing of the effects of other parameters on flow.


2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Vahid Rezania ◽  
Dennis Coombe ◽  
Jack Tuszynski

Tissue engineering, with the goal of repairing or replacing damaged tissue and organs, has continued to make dramatic science-based advances since its origins in the late 1980’s and early 1990’s. Such advances are always multi-disciplinary in nature, from basic biology and chemistry through physics and mathematics to various engineering and computer fields. This review will focus its attention on two topics critical for tissue engineering liver development: (a) fluid flow, zonation, and drug screening, and (b) biomechanics, tissue stiffness, and fibrosis, all within the context of 3D structures. First, a general overview of various bioreactor designs developed to investigate fluid transport and tissue biomechanics is given. This includes a mention of computational fluid dynamic methods used to optimize and validate these designs. Thereafter, the perspective provided by computer simulations of flow, reactive transport, and biomechanics responses at the scale of the liver lobule and liver tissue is outlined, in addition to how bioreactor-measured properties can be utilized in these models. Here, the fundamental issues of tortuosity and upscaling are highlighted, as well as the role of disease and fibrosis in these issues. Some idealized simulations of the effects of fibrosis on lobule drug transport and mechanics responses are provided to further illustrate these concepts. This review concludes with an outline of some practical applications of tissue engineering advances and how efficient computational upscaling techniques, such as dual continuum modeling, might be used to quantify the transition of bioreactor results to the full liver scale.


2004 ◽  
Vol 57 (6) ◽  
pp. 515-549 ◽  
Author(s):  
Raouf A Ibrahim

This review article deals with the random excitation of nonlinear strings and suspended cables in air and fluid flow. For strings and 1D cables, the system dynamics is governed by different forms of Duffing oscillator. A brief review is devoted to the stochastic excitation of a Duffing oscillator. Under random excitation, this oscillator may or may not possess multiple solutions depending on the excitation bandwidth and level. One may be interested in estimating response statistics, first passage problem, and power spectral density. Particular attention is given to the complex response phenomena associated with increasing the spectral density level of excitation. The numerical results of the problem of nonlinear modal interaction in suspended cables will be discussed in the neighborhood of multiple internal resonance conditions. For a unimodal response, the linear theory fails to predict nonzero mean response and underestimates the mean square response under white noise excitation. Complex response phenomena such as “on-off” intermittency, energy transfer, and stochastic bifurcation are reviewed. The dynamic behavior of suspended cables in still air is different from that in flowing fluid or severe wind current due to the action of vortices, fluid normal forces, added fluid inertia force, and fluid drag force. Aeolian and galloping vibration of suspended cables in air and their dynamics in fluid flow are discussed, together with the influence of dynamic tension. In the absence of external excitation, the action of fluid forces induces vibration to the cable. The dynamics of cables subjected to steady and random fluid flow is reviewed for mooring systems. Depending on the flow speed, the cable may experience divergence or flutter similar to the case of aeroelastic structures. While the deterministic theory of strings and cables has reached an advanced stage, the reader will realize that these systems need further investigations under random excitations. There are 297 references cited in this review article.


SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 589-600 ◽  
Author(s):  
Wei Yu ◽  
Kamy Sepehrnoori ◽  
Tadeusz W. Patzek

Summary Production from shale-gas reservoirs plays an important role in natural-gas supply in the United States. Horizontal drilling and multistage hydraulic fracturing are the two key enabling technologies for the economic development of these shale-gas reservoirs. It is believed that gas in shale reservoirs is mainly composed of free gas within fractures and pores and adsorbed gas in organic matter (kerogen). It is generally assumed in the literature that the monolayer Langmuir isotherm describes gas-adsorption behavior in shale-gas reservoirs. However, in this work, we analyzed four experimental measurements of methane adsorption from the Marcellus Shale core samples that deviate from the Langmuir isotherm, but obey the Brunauer-Emmett-Teller (BET) isotherm. To the best of our knowledge, it is the first time to find that methane adsorption in a shale-gas reservoir behaves similar to multilayer adsorption. Consequently, investigation of this specific gas-desorption effect is important for accurate evaluation of well performance and completion effectiveness in shale-gas reservoirs on the basis of the BET isotherm. The difference in calculating original gas in place (OGIP) on the basis of both isotherms is discussed. We also performed history matching with one production well from the Marcellus Shale and evaluated the contribution of gas desorption to the well's performance. History matching shows that gas adsorption obeying the BET isotherm contributes more to overall gas recovery than gas adsorption obeying the Langmuir isotherm, especially at early time in production. This work provides better understanding of gas desorption in shale-gas reservoirs and updates our current analytical and numerical models for simulation of shale-gas production.


2018 ◽  
Vol 126 (3) ◽  
pp. 633-653 ◽  
Author(s):  
Jalal Foroozesh ◽  
Amr Ibrahim Mohamed Abdalla ◽  
Zhien Zhang

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