Characterization and Measurement of Multiscale Gas Transport in Shale-Core Samples

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 573-588 ◽  
Author(s):  
K. R. Alnoaimi ◽  
C.. Duchateau ◽  
A. R. Kovscek
Keyword(s):  
Gas Flow ◽  
Gas Transport ◽  
Numerical Models ◽  
Rock Properties ◽  
Eagle Ford ◽  
Dual Porosity Model ◽  
Porosity And Permeability ◽  
And Diffusion ◽  
Porosity Model

Summary This work introduces an experimental technique to probe simultaneously flow and diffusion of gas through shale. A core-scale pressure-pulse-decay experiment is used to study the upstream- and downstream-pressure responses of Eagle Ford and Haynesville shale samples. With the aid of numerical models, the pressure histories obtained from the experiments are matched and gas and rock properties are obtained. The experiments are conducted at varying pore pressure and net effective stress to understand the sensitivity of the rock porosity and permeability as well as the gas diffusivity. A dual-porosity model is constructed to examine gas transport through a system of micropores and microcracks. In this sense, the role of the two different-sized pore systems is deconvolved. In some cases, the micropore system carries roughly one-third of the gas flow. The porosity, permeability, and diffusivity obtained assign physical properties to the macroscales and microscales simultaneously. Results bridge the gap between these scales and improve our understanding of how to assign transport physics to the correct pore scale.

Simulation and history matching of a shale gas reservoir using different models in Eagle Ford Basin

2012 ◽  
Vol 52 (2) ◽  
pp. 648
Author(s):  
Bingxiang Xu ◽  
Manouchehr Haghighi ◽  
D Cooke
Keyword(s):  
History Matching ◽  
Dual Porosity ◽  
Production Data ◽  
Gas Reservoir ◽  
Eagle Ford ◽  
Shale Gas Reservoir ◽  
Production Forecasting ◽  
Dual Porosity Model ◽  
Early Production ◽  
Porosity Model

Eagle Ford Shale in South Texas is one of the recent shale play in the US, which began developing in late 2008. To evaluate the reservoir performance and make the production forecasting for this reservoir, one multi-stage fractured horizontal well was modelled and history matching was done using the available 250 days of production data. Two different flow models of dual-porosity and multi-porosity have been examined. In the multi-porosity model, both approaches of instant and time-dependent sorption have been investigated. Also, two approaches of negative skin and transverse fractures were used to model the effect of hydraulic fracturing. For history matching of early production data, all the models were successfully matched; however, all models predict differently for production forecasting. Comparing both production forecasts for 10 years, the multi-porosity model forecasts 14% more than dual-porosity model. This is because in the dual-porosity model, only free porosity is considered and no adsorbed gas in micro-pores is assumed; in multi-porosity model, both macro and micro porosities are active in shale gas reservoir. It is concluded that the early production data is not reliable to validate the simulation and make the production forecasting. This is because in early production data, all gas are produced from the fracture system and the matrix contribution is not significant or it has not been started yet. Furthermore, the effect of matrix sub-division on the simulation was studied: the free gas in matrix can contribute to production more quickly when matrix sub-cells increase.

scholarly journals Modeling of transient shape factor in fractured reservoirs considering the effect of heterogeneity, pressure-dependent properties and quadratic pressure gradient

2019 ◽  
Vol 74 ◽  
pp. 89
Author(s):  
Mahdi Abbasi ◽  
Alireza Kazemi ◽  
Mohammad Sharifi
Keyword(s):  
Pressure Gradient ◽  
Shape Factor ◽  
Fractured Reservoirs ◽  
Dual Porosity ◽  
Rock Properties ◽  
High Porosity ◽  
Matrix Block ◽  
Dual Porosity Model ◽  
The Matrix ◽  
Porosity Model

Fractured reservoirs contain most of the oil in the world’s reserves. The existence of two systems of matrix and fracture with completely different characteristics has caused the modeling of the mechanisms of fractured reservoirs to be more complex than conventional ones. Modeling of this type of reservoirs is possible using two methods of single and dual porosity model. Modeling via single porosity scheme is very time-consuming as it takes into account huge matrix blocks (low permeability and high porosity) and small fractures (high permeability and low porosity) alongside each other explicitly. The dual porosity model, however, attempts to solve this problem using the concept of shape factor, which is defined as the amount of fluid transferred from the matrix to the fracture. The shape factor coefficients expressed so far have been derived via simplifying assumptions which keep them away from real conditions prevailing in fractured reservoirs. In this paper, shape factor is calculated more realistically with consideration of the quadratic pressure gradient in the diffusivity equation, the heterogeneity of the matrix block and the change of the rock properties by pressure change. For these three cases, the analytical modeling of the flow of fluid from the matrix to the fracture system has been discussed and its results with previous models have been compared. In addition, the dependence of shape factor on the stated parameters was evaluated and in order to validate the results of the proposed analytical model, its results were compared with the results of a commercial simulator. Investigating the shape factor with the assumptions about the physics of the fractured reservoirs will improve our understanding of the fluid transfer between the matrix and the fracture, and this capability will allow numerical and commercial simulators to predict the behavior of fractured reservoirs more accurately.

PERMEABILITY AND DIFFUSION COEFFICIENT PREDICTION OF FRACTAL POROUS MEDIA WITH NANOSCALE PORES FOR GAS TRANSPORT

2018 ◽  
Vol 21 (12) ◽  
pp. 1253-1263
Author(s):  
Ruifei Wang ◽  
Hongqing Song ◽  
Jiulong Wang ◽  
Yuhe Wang
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Gas Transport ◽  
And Diffusion

Effect of cluster-gradient architecture of nanostructured topocomposites on features of tribointeraction with heterophased material

2020 ◽  
pp. 130-135
Author(s):  
D.N. Korotaev ◽  
K.N. Poleshchenko ◽  
E.N. Eremin ◽  
E.E. Tarasov
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Energy Dissipation ◽  
Phase Structure ◽  
Diffusion Processes ◽  
Structural Phase ◽  
High Wear Resistance ◽  
Wear Characteristics ◽  
And Diffusion

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.

The role of gas flow distributions on CO2 mineralization within monolithic cemented composites: coupled CFD-factorial design approach

2021 ◽  
Author(s):  
Iman Mehdipour ◽  
Gabriel Falzone ◽  
Dale Prentice ◽  
Narayanan Neithalath ◽  
Dante Simonetti ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Factorial Design ◽  
Material Properties ◽  
Gas Flow ◽  
Design Approach ◽  
Processing Conditions ◽  
Gas Processing ◽  
Co2 Mineralization

Optimizing the spatial distribution of contacting gas and the gas processing conditions enhances CO2 mineralization reactions and material properties of carbonate-cementitious monoliths.

On the Role of Charged Defect States and Deep Traps in the Photocarrier Drift and Diffusion in a-Si:H

2000 ◽  
Vol 609 ◽  
Author(s):  
Paul Stradins ◽  
Akihisa Matsuda
Keyword(s):  
Particle Number ◽  
Defect States ◽  
Total Electron ◽  
Minority Carrier Diffusion Length ◽  
Continuity Equations ◽  
Effective Mobility ◽  
Almost All ◽  
Charged Defects ◽  
And Diffusion

ABSTRACTThe drift and diffusion in the presence of charged defects and photocarriers trapped in the tail states is re-examined. In continuity equations, diffusive and drift currents are related to free particles while the Poisson equation includes all charges. In order to make use of ambipolar diffusion approximation, the mobilities and diffusion coefficients should be attributed to the total electron and hole populations making them strongly particle-number dependent. Due to the asymmetry of the conduction and valence band tails, almost all trapped electrons reside in negatively charged defects (D−). A simple model of photocarrier traffic via tail and defect states allows to establish the effective mobility values and coefficients in Einstein relations. In a photocarrier grating experiment, grating of D− is counterbalanced by the grating of trapped holes. Nevertheless, electrons remain majority carriers, allowing the measurement of minority carrier diffusion length, but analysis is needed to relate the latter with μτ product.

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