Permeability dynamic variation under the action of stress in the medium and high rank coal reservoir

Zhao, Jiaxin; Tang, Dazhen; Lin, Weiren; Xu, Hao; Li, Yong; Tao, Shu; Lv, Yumin

doi:10.1016/j.jngse.2015.08.001

Cited by 52 publications

(34 citation statements)

References 45 publications

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“…Therefore, the reservoir permeability dynamic change formula is given by Equation (14). In order to quantitatively analyze the permeability recovery, the recovery pressure ( ) is defined as the reservoir pressure, where reservoir permeability is recovered to initial permeability (Equation (15)). If the recovery pressure is greater than 0, the coal reservoir is a recoverable reservoir.…”

Section: Reservoir Properties In the Whole Production Stagementioning

confidence: 99%

“…Advanced Characterization of P rb and P rc P rb and P rc can be calculated based on the coal reservoir parameters using Equations (13) and (15). In order to study the influence of geological factors on P rb and P rc , an orthogonal test was designed, which is one of the most effective and time-saving methods for studies involving multiple variables to determine which factors (or variables) primarily influence the properties of the target product [44].…”

Section: Advanced Characterization Of the Four Demarcating Pressures mentioning

confidence: 99%

“…Multiple permeability models have been developed to describe coal permeability behavior. Coal permeability models considering the effect of effective stress were first proposed [14][15][16], followed by models considering the effect of sorption-induced strain on coal permeability evolution [17][18][19]. Some models have proven popular with practitioners, such as the Seidle model, P&M model, S&D model, and Pan & Connell model [12,14,[20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Comprehensive Coal Reservoir Classification Method Base on Permeability Dynamic Change and Its Application

et al. 2020

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Due to the unique adsorption and desorption characteristics of coal, coal reservoir permeability changes dynamically during coalbed methane (CBM) development. Coal reservoirs can be classified using a permeability dynamic characterization in different production stages. In the single-phase water flow stage, four demarcating pressures are defined based on the damage from the effective stress on reservoir permeability. Coal reservoirs are classified into vulnerable, alleviative, and invulnerable reservoirs. In the gas desorption stage, two demarcating pressures are used to quantitatively characterize the recovery properties of permeability based on the recovery effect of the matrix shrinkage on permeability, namely the rebound pressure (the pressure corresponding to the lowest permeability) and recovery pressure (the pressure when permeability returns to initial permeability). Coal reservoirs are further classified into recoverable and unrecoverable reservoirs. The physical properties and influencing factors of these demarcating pressures are analyzed. Twenty-six wells from the Shizhuangnan Block in the southern Qinshui Basin of China were examined as a case study, showing that there is a significant correspondence between coal reservoir types and CBM well gas production. This study is helpful for identifying geological conditions of coal reservoirs as well as the productivity potential of CBM wells.

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Section: Reservoir Properties In the Whole Production Stagementioning

confidence: 99%

Section: Advanced Characterization Of the Four Demarcating Pressures mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A Comprehensive Coal Reservoir Classification Method Base on Permeability Dynamic Change and Its Application

et al. 2020

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“…Li et al 23 tested coal samples associated with cleat pattern and showed that Kushiro coal is anisotropic with respect to gas permeability, where the permeability parallel to bedding plane and face cleat is larger than that perpendicular to the bedding plane and the permeability perpendicular to the bedding plane is larger than that parallel to the bedding plane and butt cleat. Li Yong et al 24 and Zhao Junlong et al 25 drill three columned cores from one source samples of different drilling directions for the investigation of permeability difference between coal cores, and the nature of helium permeability change was measured on different rank coal cores. The experimental results showed that the coal permeability declined exponentially with the rise of effective stress.…”

Section: Gas Flow Directionmentioning

confidence: 99%

Influence radius of gas extraction borehole in an anisotropic coal seam: Underground in‐situ measurement and modeling

Yue

Hui

Yue

et al. 2019

Energy Science & Engineering

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Coal seam degasification by in‐seam drilling borehole is one of the popular techniques for coal mine methane (CMM) control. How to address the conflict between borehole numbers and drainage durations always arouses researchers’ interests. Furthermore, since coal has anisotropy structures, how the anisotropy feature of coal associated with bedding and cleat structure affects the influence radius of the drainage borehole has rarely been considered. In order to address the above‐mentioned issues, this work not only conducted underground in‐situ measurement of the borehole influence radius within 200 days in an anisotropy coal seam at Jiulishan coal mine in China, but also modeled the influence radius evolvement around borehole in an anisotropy coal seam using finite‐element based COMSOL package. The underground in‐situ measurement revealed an anisotropy feature of borehole influence radius associated with coal bedding and cleat structures. The influence radius of borehole parallel to the bedding plane in butt cleat direction is much larger than that perpendicular to the bedding plane. Ten permeability measurements of coal show that the permeability of coal parallel to the bedding plane in butt cleat direction is higher than that perpendicular to the bedding plane. Simulation results of the gas transport model in coal are consistent with underground in‐situ measurement in determining the influence radius of drainage borehole in the anisotropy coal seam. Based on modeling results, the ellipse influence area of borehole in an anisotropy coal seam is proposed, and the relationship between the influence radius of borehole and drainage time is obtained. On the basis of these findings, the proper in‐seam borehole arrangements for a specific mining panel at different drainage durations are determined. The finding of this work will be fundamental for addressing the conflict between minimizing the cost of borehole arrangement and increasing coal mining productions by adjusting CMM drainage durations.

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“…[17][18][19] In order to describe the change law of the coal seam permeability, the relationship between macroscopic mechanical properties (such as deviation stress, effective stress, and fracture volume) and the permeability of damaged coal was established based on test data . [20][21][22][23] The macroscopic mechanics and gas permeability of the coal were mainly studied. However, due to the limitations of testing equipment, the mechanical mechanism for coal damage evolution and its effect on gas permeability were rarely studied.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the evolution of damage and permeability of coal containing gas based on acoustic emission characteristics

Liu

Zhou

2020

Asia-Pacific J Chem Eng

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The gas permeability of a coal seam was the main factor determining the efficiency of gas extraction from the mines and was closely related to the coal damages. In this paper, a triaxial compression failure test of the raw coal was carried out in the gas seepage state using the MTS 815 rock mechanics testing system. The damage evolution law of the coal containing gas under triaxial compression was studied based on acoustic emission characteristics. The damage evolution parameters were determined using acoustic emission signals, and the relationship between the permeability and damage evolution of the coal containing gas was quantitatively analyzed. The results demonstrated that the acoustic emission signals could reflect the development of the damage and failure inside the coal, and the turning point of the acoustic emission characteristic curve marked different damage development stages. The periodic changes in the permeability of the coal samples were consistent with the damage change law, and some lag existed in permeability changes compared with damage evolution. The permeability of the coal containing gas saw a stepwise exponential growth with the damage development. The piecewise exponential function better reflected the relationship between the gas permeability and damage variables.

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Permeability dynamic variation under the action of stress in the medium and high rank coal reservoir

Cited by 52 publications

References 45 publications

A Comprehensive Coal Reservoir Classification Method Base on Permeability Dynamic Change and Its Application

A Comprehensive Coal Reservoir Classification Method Base on Permeability Dynamic Change and Its Application

Influence radius of gas extraction borehole in an anisotropic coal seam: Underground in‐situ measurement and modeling

Investigation of the evolution of damage and permeability of coal containing gas based on acoustic emission characteristics

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