scholarly journals Experimental Study on Gas Transport in Shale Matrix with Real Gas and Klinkenberg Effects

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaojun Wu ◽  
Qing Wang ◽  
Fangtao Lyu ◽  
Zhengfu Ning ◽  
Zongxiao Ren
Keyword(s):  
Oil And Gas ◽  
Gas Transport ◽  
Data Interpretation ◽  
Positive Influence ◽  
Ideal Gas ◽  
Klinkenberg Effect ◽  
Production Forecast ◽  
Real Gas ◽  
Longmaxi Shale ◽  
Deviation Factor

Gas transport in shale matrix is complex due to multiple mechanisms and is difficult to be investigated by macroscopic experiment. For Gas Research Institute (GRI) method, which is the most accepted one for gas transport investigation in shale matrix, the apparatus was modified by adding an automatic gas supplement and pressurization (AGSP) system, and a numerical model considering the variation of real gas property and the Klinkenberg effect was established for data interpretation. Then, the intrinsic permeability and Klinkenberg coefficient were effectively obtained by maintaining high expanding speed of gas in apparatus and eliminating the negative effect of low filling degree of sample. By analysis, the ideal gas transports faster than real gas due to the viscosity difference at low pressure and the deviation factor difference at high pressure. For Wufeng-Longmaxi shale matrix, the positive influence of Klinkenberg effect on gas transport would attenuate with increasing pressure and is more powerful than bulk shale sample with fractures. Therefore, the gas transport in real shale matrix could be well known, which is meaningful to production forecast and evaluation in oil and gas fields.

scholarly journals Experimental determination of deviation factor of natural gas in natural gas reservoir with high CO2 content

2021 ◽  
Vol 245 ◽  
pp. 01045
Author(s):  
Guofang Zhang ◽  
Taoping Chen ◽  
Fuping Wang ◽  
Boyu Sun ◽  
Yong Wang ◽  
...  
Keyword(s):  
Porous Media ◽  
Natural Gas ◽  
Ideal Gas ◽  
Gas Reservoir ◽  
Real Gas ◽  
Mining Conditions ◽  
Deviation Factor ◽  
In Series ◽  
Deviation Degree

The deviation factor of natural gas is a coefficient to quantitatively describe the deviation degree between real gas (natural gas) and ideal gas. Generally, the deviation factor of natural gas is measured in PVT cell without considering porous media. However, when natural gas is in underground porous media reservoir, due to the adsorption of porous media, the deviation factor of natural gas in porous media deviates from that measured in conventional PVT cell. Moreover, compared with other gases, CO2 has stronger adsorption capacity. Therefore, in porous media, the deviation factor of natural gas considering the adsorption of porous media is quite different from that measured in conventional PVT cell. In this paper, simulating the isothermal mining conditions in gas reservoir,the deviation factor of natural gas with different CO2 content considering the influence of porous media under different pressure isothermal conditions is studied by using the test of designed sand filled long slim tube in series. And under the same conditions, the deviation factor is compared with that of conventional PVT. The experimental results show that under the same conditions, due to the adsorption of porous media, the deviation factor measured in porous media is smaller than that measured by PVT cell without considering porous media.

The Structure of Laminar Premixed H2-Air Flames at Elevated Pressures

2000 ◽  
Vol 214 (4) ◽  
Author(s):  
M. El-Gamal ◽  
E. Gutheil ◽  
J. Warnatz
Keyword(s):  
Laminar Flame ◽  
Flame Structure ◽  
Ideal Gas ◽  
Fortran Program ◽  
Laminar Flame Speed ◽  
Real Gas ◽  
One Dimensional ◽  
Rocket Propulsion ◽  
Elevated Pressures ◽  
Engine Combustion

In high-pressure flames that occur in many practical combustion devices such as industrial furnaces, rocket propulsion and internal engine combustion, the assumption of an ideal gas is not appropriate. The present paper presents a model that includes modifications of the equation of state, transport and thermodynamic properties. The model is implemented into a Fortran program that was developed to simulate numerically one-dimensional planar premixed flames. The influence of the modifications for the real gas behavior on the laminar flame speed and on flame structure is illustrated for stoichiometric H

Well Logging Data Interpretation in Oil and Gas Source Rock Sections Based on Complex Petrophysical and Geochemical Analysis Results

2018 ◽  
Author(s):  
Rais Khisamov ◽  
Natalya Skibitskaya ◽  
Kazimir Kovalenko ◽  
Venera Bazarevskaya ◽  
Nikita Samokhvalov ◽  
...  
Keyword(s):  
Source Rock ◽  
Oil And Gas ◽  
Data Interpretation ◽  
Well Logging ◽  
Geochemical Analysis ◽  
Gas Source

A FRACTAL PERMEABILITY MODEL FOR REAL GAS IN SHALE RESERVOIRS COUPLED WITH KNUDSEN DIFFUSION AND SURFACE DIFFUSION EFFECTS

Fractals ◽  
2020 ◽  
Vol 28 (01) ◽  
pp. 2050017 ◽  
Author(s):  
TAO WU ◽  
SHIFANG WANG
Keyword(s):  
Fractal Dimension ◽  
Surface Diffusion ◽  
Shale Gas ◽  
Gas Transport ◽  
Fractal Theory ◽  
Knudsen Diffusion ◽  
Apparent Permeability ◽  
Permeability Model ◽  
Real Gas ◽  
Shale Reservoirs

A better comprehension of the behavior of shale gas transport in shale gas reservoirs will aid in predicting shale gas production rates. In this paper, an analytical apparent permeability expression for real gas is derived on the basis of the fractal theory and Fick’s law, with adequate consideration of the effects of Knudsen diffusion, surface diffusion and flexible pore shape. The gas apparent permeability model is found to be a function of microstructural parameters of shale reservoirs, gas property, Langmuir pressure, shale reservoir temperature and pressure. The results show that the apparent permeability increases with the increase of pore area fractal dimension and the maximum effective pore radius and decreases with an increase of the tortuosity fractal dimension; the effects of Knudsen diffusion and surface diffusion on the total apparent permeability cannot be ignored under high-temperature and low-pressure circumstances. These findings can contribute to a better understanding of the mechanism of gas transport in shale reservoirs.

Analytical Model for Real Gas Transport in Shale Reservoirs with Surface Diffusion of Adsorbed Gas

2019 ◽  
Vol 58 (51) ◽  
pp. 23481-23489 ◽  
Author(s):  
Tianyu Wang ◽  
Shouceng Tian ◽  
Gensheng Li ◽  
Panpan Zhang
Keyword(s):  
Surface Diffusion ◽  
Analytical Model ◽  
Gas Transport ◽  
Real Gas ◽  
Adsorbed Gas ◽  
Shale Reservoirs

Multiple-flow-regime models for real gas transport in fractal porous media at high pressure

2021 ◽  
Vol 196 ◽  
pp. 107684
Author(s):  
Lan Zhang ◽  
Yingjun Wang ◽  
Ming Liu ◽  
Liquan Wang ◽  
Hengxu Liu
Keyword(s):  
High Pressure ◽  
Porous Media ◽  
Flow Regime ◽  
Gas Transport ◽  
Real Gas

scholarly journals Mathematical Model of Small-Volume Air Vessel Based on Real Gas Equation

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 530 ◽  
Author(s):  
Weixiang Ni ◽  
Jian Zhang ◽  
Lin Shi ◽  
Tengyue Wang ◽  
Xiaoying Zhang ◽  
...  
Keyword(s):  
Water Depth ◽  
Small Volume ◽  
Pressure Oscillation ◽  
State Equation ◽  
Ideal Gas ◽  
Pipeline System ◽  
Real Gas ◽  
Polytropic Equation ◽  
Real Gas Equations ◽  
Ideal Gas Model

The gas characteristics of an air vessel is one of the key parameters that determines the protective effect on water hammer pressure. Because of the limitation of the ideal gas state equation applied for a small-volume vessel, the Van der Waals (VDW) equation and Redlich–Kwong (R–K) equation are proposed to numerically simulate the pressure oscillation. The R–K polytropic equation is derived under the assumption that the volume occupied by the air molecules themselves could be ignored. The effects of cohesion pressure under real gas equations are analyzed by using the method of characteristics under different vessel diameters. The results show that cohesion pressure has a significant effect on the small volume vessel. During the first phase of the transient period, the minimum pressure and water depth calculated by a real gas model are obviously lower than that calculated by an ideal gas model. Because VDW cohesion pressure has a stronger influence on the air vessel pressure compared to R–K air cohesion pressure, the amplitude of head oscillation in the vessel calculated by the R–K equation becomes larger. The numerical results of real gas equations can provide a higher safe-depth margin of the water depth required in the small-volume vessel, resulting in the safe operation of the practical pumping pipeline system.

The performance of spiral groove dry gas seal under choked flow condition considering the real gas effect

2019 ◽  
Vol 234 (4) ◽  
pp. 554-566
Author(s):  
Hengjie Xu ◽  
Pengyun Song ◽  
Wenyuan Mao ◽  
Qiangguo Deng
Keyword(s):  
Carbon Dioxide ◽  
Flow Condition ◽  
Ideal Gas ◽  
Leakage Rate ◽  
Spiral Groove ◽  
Real Gas ◽  
Dry Gas Seal ◽  
Choked Flow ◽  
Real Gas Effect ◽  
Gas Effect

By taking carbon dioxide and hydrogen as lubricating gas, respectively, this paper presents an analysis on the pressure characteristics and temperature distribution of spiral groove dry gas seal which influenced by real gas effect under choked flow condition. Numerical results show that the deviation between real gas and ideal gas, which expressed by the deviation degree between compressibility factor Z and 1, is the main reason for real gas effect affecting sealing performance. Compared with ideal gas model, real gas effect raises exit pressure, opening force, leakage rate, Mach number in dam region, and temperature for carbon dioxide ( Z < 1), while it decreases those characteristics for hydrogen ( Z > 1) under the same operating conditions. In addition, choked flow effect increases opening force and reduces leakage rate and temperature-drop between entrance and exit of sealing clearance. Meanwhile, it may cause an unstable behavior for the seal.

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