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Qingwang Yuan - One of the best experts on this subject based on the ideXlab platform.
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experimental study on permeability in tight porous media considering gas adsorption and Slippage Effect
Fuel, 2019Co-Authors: Jinjie Wang, Long Yu, Qingwang YuanAbstract:Abstract Permeability is an important parameter that helps understand the gas mass transport behavior in tight porous media. However, measuring the permeability of tight porous media accurately is an arduous task. Gas flow differs from liquid flow in regards to high compressibility, Slippage Effect, and sometimes adsorption. Slippage Effect can be significant when the pressure is low or the pore diameter is small. Increasing pressure eliminates the Slippage Effect; however, high pressure is not always achievable under lab or field production conditions. The measurement of permeability during gas flow in a porous media is also greatly affected by the adsorption-induced surface diffusion process. In this study, a combined experimental–mathematical method for determining the permeability of tight porous media was developed. Steady-state measurements were conducted to obtain methane flux under different pressures for shale and tight reservoirs. The apparent permeability and permeability without Slippage were calculated. Using the measured parameters, a mathematical model was derived to determine the intrinsic permeability, and the viability was tested with experimental results. This work provides an alternative approach to estimate the permeability of tight porous media during the gas mass transport process by considering both the Slippage Effect and gas surface adsorption. Parameters in the model can be easily measured through experiments for low pressures. Experimental verification shows that the error of permeability estimation can be decreased by approximately 10%.
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Experimental study on permeability in tight porous media considering gas adsorption and Slippage Effect
Fuel, 2019Co-Authors: Jinjie Wang, Qingwang YuanAbstract:Abstract Permeability is an important parameter that helps understand the gas mass transport behavior in tight porous media. However, measuring the permeability of tight porous media accurately is an arduous task. Gas flow differs from liquid flow in regards to high compressibility, Slippage Effect, and sometimes adsorption. Slippage Effect can be significant when the pressure is low or the pore diameter is small. Increasing pressure eliminates the Slippage Effect; however, high pressure is not always achievable under lab or field production conditions. The measurement of permeability during gas flow in a porous media is also greatly affected by the adsorption-induced surface diffusion process. In this study, a combined experimental–mathematical method for determining the permeability of tight porous media was developed. Steady-state measurements were conducted to obtain methane flux under different pressures for shale and tight reservoirs. The apparent permeability and permeability without Slippage were calculated. Using the measured parameters, a mathematical model was derived to determine the intrinsic permeability, and the viability was tested with experimental results. This work provides an alternative approach to estimate the permeability of tight porous media during the gas mass transport process by considering both the Slippage Effect and gas surface adsorption. Parameters in the model can be easily measured through experiments for low pressures. Experimental verification shows that the error of permeability estimation can be decreased by approximately 10%.
Jinjie Wang - One of the best experts on this subject based on the ideXlab platform.
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experimental study on permeability in tight porous media considering gas adsorption and Slippage Effect
Fuel, 2019Co-Authors: Jinjie Wang, Long Yu, Qingwang YuanAbstract:Abstract Permeability is an important parameter that helps understand the gas mass transport behavior in tight porous media. However, measuring the permeability of tight porous media accurately is an arduous task. Gas flow differs from liquid flow in regards to high compressibility, Slippage Effect, and sometimes adsorption. Slippage Effect can be significant when the pressure is low or the pore diameter is small. Increasing pressure eliminates the Slippage Effect; however, high pressure is not always achievable under lab or field production conditions. The measurement of permeability during gas flow in a porous media is also greatly affected by the adsorption-induced surface diffusion process. In this study, a combined experimental–mathematical method for determining the permeability of tight porous media was developed. Steady-state measurements were conducted to obtain methane flux under different pressures for shale and tight reservoirs. The apparent permeability and permeability without Slippage were calculated. Using the measured parameters, a mathematical model was derived to determine the intrinsic permeability, and the viability was tested with experimental results. This work provides an alternative approach to estimate the permeability of tight porous media during the gas mass transport process by considering both the Slippage Effect and gas surface adsorption. Parameters in the model can be easily measured through experiments for low pressures. Experimental verification shows that the error of permeability estimation can be decreased by approximately 10%.
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Experimental study on permeability in tight porous media considering gas adsorption and Slippage Effect
Fuel, 2019Co-Authors: Jinjie Wang, Qingwang YuanAbstract:Abstract Permeability is an important parameter that helps understand the gas mass transport behavior in tight porous media. However, measuring the permeability of tight porous media accurately is an arduous task. Gas flow differs from liquid flow in regards to high compressibility, Slippage Effect, and sometimes adsorption. Slippage Effect can be significant when the pressure is low or the pore diameter is small. Increasing pressure eliminates the Slippage Effect; however, high pressure is not always achievable under lab or field production conditions. The measurement of permeability during gas flow in a porous media is also greatly affected by the adsorption-induced surface diffusion process. In this study, a combined experimental–mathematical method for determining the permeability of tight porous media was developed. Steady-state measurements were conducted to obtain methane flux under different pressures for shale and tight reservoirs. The apparent permeability and permeability without Slippage were calculated. Using the measured parameters, a mathematical model was derived to determine the intrinsic permeability, and the viability was tested with experimental results. This work provides an alternative approach to estimate the permeability of tight porous media during the gas mass transport process by considering both the Slippage Effect and gas surface adsorption. Parameters in the model can be easily measured through experiments for low pressures. Experimental verification shows that the error of permeability estimation can be decreased by approximately 10%.
Chonghong Ren - One of the best experts on this subject based on the ideXlab platform.
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An Anisotropic Permeability Model for Shale Gas Recovery Considering Slippage Effect and Embedded Proppants
Natural resources research, 2020Co-Authors: Zhihe Wang, Kang Yang, Chonghong Ren, Chen ShuaiAbstract:Hydraulic fracturing has been widely adopted to improve shale gas recovery. A main issue in the implementation of hydraulic fracturing techniques is that proppants made from a variety of materials are normally introduced for the purpose of permeability enhancement. An embedded proppant can significantly alter the original gas flow behavior of shale, which should be taken into account when estimating shale permeability. In this paper, we propose a shale anisotropic permeability model that considers the Effect of proppant embedding. Moreover, because the Slippage factor is usually not fixed owing to the combined Effect of proppant embeddings, any adsorption-induced swelling and stress, a Slippage factor formulation is developed to consider the embedded proppant. Finally, an improved shale anisotropic permeability model that considers the combined Effect of proppants and Slippage is proposed. The validity of the model presented in this paper was assessed by comparing the results with previous experiments, and good agreement was found for the proposed model. The developed model can estimate accurately shale anisotropic permeability, when both the proppant and Slippage Effect are considered, and can be used to study related problems in the recovery of shale gas resources.
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An adsorption-permeability model of coal with Slippage Effect under stress and temperature coupling condition
Journal of Natural Gas Science and Engineering, 2019Co-Authors: Li Bobo, Kang Yang, Chonghong RenAbstract:Abstract Temperature and Slippage Effect, two important factors affecting coalbed methane (CBM) production, both have an intuitive Effect on gas adsorption in coal seams and coal deformation and gas seepage processes. In order to simulate the process of CBM exploitation, isothermal adsorption tests at different temperatures and seepage tests under rising pore pressure were carried out. In this study, the modified Langmuir model considering the Effects of temperature and excess adsorption was established. On this basis, the amount of adsorption deformation was calculated. The results show that the amount grows with the rise of pore pressure and is negatively related to temperature. In addition, a temperature mutation coefficient (γT) was introduced to characterize the response of coal permeability to temperature, and thermal expansion, thermal cracking, adsorption deformation induced by temperature and Slippage Effect were combined to establish a coal permeability model under the coupling of stress and temperature. Meanwhile, a helium parallel seepage test was carried out under the same conditions to study the Effects of Slippage and adsorption expansion. It is found that the rise of pore pressure will reduce permeability under the action of adsorption or Slippage Effects, and the rise of temperature will enhance the permeability. Finally, according to the experimental data, the adsorption-permeability model achieves better fitting results, compared with other models. The model can provide certain theoretical support for CBM exploitation.
Jian Yan - One of the best experts on this subject based on the ideXlab platform.
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Stress Sensitivity of Low Permeable and Water-Bearing Gas Reservoir without Gas Slippage Effect
Advanced Materials Research, 2014Co-Authors: Jian Yan, Xiao Bing Liang, Qing GuoAbstract:Because of the gas Slippage, the testing methods of stress sensitivity for gas reservoir should be different from that for oil reservoir. This text adopts the method that imposing back pressure on the outlet of testing core to weaken the gas Slippage Effect and tests the stress sensitivity of low permeability gas reservoirs, then analyzes the influence of permeability and water saturation on stress sensitivity. The results show that: low permeable and water-bearing gas reservoirs have strong stress sensitivity; the testing permeability has the power function relationship with net stress, compared to the exponential function, the fitting correlation coefficient is larger and more suited to the actual; the lower the permeability is and the higher water saturation is, the stronger the stress sensitivity is. The production of gas well is affected when considering the stress sensitivity, so the pressure dropping rate should be reasonable when low permeable gas reservoirs are developed. The results provide theoretical references for analyzing the well production and numerical simulation.
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characterization of gas flow ability and contribution of diffusion to total mass flux in the shale
Research Journal of Applied Sciences Engineering and Technology, 2013Co-Authors: Rui Wang, Xiaojuan Liu, Ningsheng Zhang, Jian YanAbstract:The aim of this study is to search a parameter which characterize the flow ability and analyze the contribution of diffusion to total mass flux of gas flow in pore of shale whose size is as low as nanoscale. The diffusion coefficient of the flow region which was determined by Kundsen number was taken as the diffusion coefficient of system, then it was substituted into the equation which describes gas diffusive and flow in nano- porous media, the apparent permeability and mass flux were calculated and the impacts of the pore radius and gas type were analyzed finally. The result showed that the diffusion of gas in shale was mainly in the transition diffusion or Fick diffusion region; The ratio of the apparent permeability of considering the diffusion and Slippage Effect to Darcy permeability and the ratio of diffusion mass flux to total mass flux increased with the decreasing of the pore radius; The diffusion ability of the methane was stronger than ethane's. The present study implied that the calculated results of the diffusion coefficient which considers three kind of diffusion was less than that one considering Knudsen diffusion only; Considering diffusion and Slippage Effect, the apparent permeability of nanoscale pore of shale was 10 -6 μm 2 level, not 10 -9 μm 2 level in general temperature and pressure of shale reservoir.
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Gas Slippage Effect in Low Permeability Water-bearing Gas Reservoirs
All Days, 2011Co-Authors: Xiaojuan Liu, Jian Yan, Yi LiuAbstract:Abstract Lab tests were carried out to study the gas Slippage and quasi starting pressure in water-bearing gas reservoirs of low permeability. The permeability of the testing cores is mainly lower than 1 mD. The testing results indicate that: for similar water saturation, the lower the permeability is, the more serious the gas Slippage is. For similar permeability, with the increasing of water saturation, the gas Slippage Effect increases first and then decreases. The turning point is called critical water saturation (Sw)c1. The relationship between the critical water saturation and the core coefficient is binomial, where the core coefficient is the ratio between permeability and porosity. By curve fitting, it was found that, when the water saturation is lower than a critical value, gas slip factor is a logarithmic function of the ratio of core coefficient and water saturation; when water saturation is higher than the critical value, the gas slip factor is a logarithmic function of the multiplication of core coefficient and water saturation. The quasi starting pressure gradient may exist when the gas flow in porous media that contains water. The reason is that the increase of capillary resistance is larger than gas Slippage as the water saturation rises. In further, it was concluded that there is another critical water saturation (Sw)c2. When the water saturation is larger than the critical value (Sw)c2, the quasi starting pressure gradient exists. The relationship between the quasi starting pressure gradient and the ratio of core coefficient and water saturation is a power function. Further more, the relationship between the critical water saturation and absolute permeability is also a power function.
Long Yu - One of the best experts on this subject based on the ideXlab platform.
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experimental study on permeability in tight porous media considering gas adsorption and Slippage Effect
Fuel, 2019Co-Authors: Jinjie Wang, Long Yu, Qingwang YuanAbstract:Abstract Permeability is an important parameter that helps understand the gas mass transport behavior in tight porous media. However, measuring the permeability of tight porous media accurately is an arduous task. Gas flow differs from liquid flow in regards to high compressibility, Slippage Effect, and sometimes adsorption. Slippage Effect can be significant when the pressure is low or the pore diameter is small. Increasing pressure eliminates the Slippage Effect; however, high pressure is not always achievable under lab or field production conditions. The measurement of permeability during gas flow in a porous media is also greatly affected by the adsorption-induced surface diffusion process. In this study, a combined experimental–mathematical method for determining the permeability of tight porous media was developed. Steady-state measurements were conducted to obtain methane flux under different pressures for shale and tight reservoirs. The apparent permeability and permeability without Slippage were calculated. Using the measured parameters, a mathematical model was derived to determine the intrinsic permeability, and the viability was tested with experimental results. This work provides an alternative approach to estimate the permeability of tight porous media during the gas mass transport process by considering both the Slippage Effect and gas surface adsorption. Parameters in the model can be easily measured through experiments for low pressures. Experimental verification shows that the error of permeability estimation can be decreased by approximately 10%.