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.

Investigations of Energy Separation Effect in Vortex Tube for Real Gases

2013 ◽  
Vol 724-725 ◽  
pp. 1293-1300
Author(s):  
Jing Tang ◽  
Wen Chuan Wang ◽  
Xiang Jun Fang ◽  
Shi Long Liu ◽  
Wen Long Sun
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Vortex Tube ◽  
Ideal Gas ◽  
Energy Separation ◽  
Separation Effect ◽  
Real Gas ◽  
Real Gas Effect ◽  
Effect Difference ◽  
Gas Effect

This paper aims to investigate real gases energy separation effect such as real natural gas, CH4 and C2H4 in vortex tube. Energy separation phenomena of real natural gas (RNG) were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of ideal natural gas (ING), or RNG in low and high pressure were simulated. The results main factors were found that affect the separation effect. At the same time, this paper has illustrated the effect and tendency of energy separation with real gas in the tube under the same cold mass fraction and pressure ratio. The results show low pressure ideal gas and real gas energy separation effect difference about 3-4°C, the real gas effect is not obvious; High pressure real natural gas (HPRNG) and ideal gas (HPING) effect difference is 13-14°C, the real gas effect is obvious; CH4 (LRCH4) and C2H4 (HRC2H4) energy separation effect is obvious and effect of real gas is generated.

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 Acceleration of Gas Reservoir Simulation Using Proper Orthogonal Decomposition

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yi Wang ◽  
Bo Yu ◽  
Ye Wang
Keyword(s):  
High Precision ◽  
Reservoir Simulation ◽  
Gas Flow ◽  
Ideal Gas ◽  
Reduced Order Model ◽  
Order Model ◽  
Gas Reservoir ◽  
Reduced Order ◽  
Real Gas ◽  
Proper Orthogonal

High-precision and high-speed reservoir simulation is important in engineering. Proper orthogonal decomposition (POD) is introduced to accelerate the reservoir simulation of gas flow in single-continuum porous media via establishing a reduced-order model by POD combined with Galerkin projection. Determination of the optimal mode number in the reduced-order model is discussed to ensure high-precision reconstruction with large acceleration. The typical POD model can achieve high precision for both ideal gas and real gas using only 10 POD modes. However, acceleration of computation can only be achieved for ideal gas. The obstacle of POD acceleration for real gas is that the computational time is mainly occupied by the equation of state (EOS). An approximation method is proposed to largely promote the computational speed of the POD model for real gas flow without decreasing the precision. The improved POD model shows much higher acceleration of computation with high precision for different reservoirs and different pressures. It is confirmed that the acceleration of the real gas reservoir simulation should use the approximation method instead of the computation of EOS.

scholarly journals Ideal cycle of combustion engine with natural gas as a fuel

2016 ◽  
Vol 62 (Special Issue) ◽  
pp. S14-S20 ◽  
Author(s):  
I. Vitázek ◽  
J. Klúčik ◽  
J. Jablonický ◽  
P. Vereš
Keyword(s):  
Natural Gas ◽  
Combustion Engine ◽  
Ideal Gas ◽  
Precise Determination ◽  
Combustion Engines ◽  
Compressed Natural Gas ◽  
Working Cycle ◽  
Residual Space ◽  
Determination Of Parameters

The aim of the paper is to present a detailed methodology of calculations of parameters of an ideal working cycle of spark-ignition combustion engine. Natural gas in the form of compressed natural gas (CNG) was used as a fuel. A theoretical ideal cycle is currently described in simplified way. The paper introduces calculations considering excess air, residual space in the cylinder of the engine and the course of properties of gases in dependence on temperature. The thermodynamics of ideal gas mixture was used. A computer program for clear, quick and accurate calculations of this relatively complicated system of relations was designed. The presented methodology of calculations broadens the scope of the theory of combustion engines and enables a precise determination of parameters of combustion engine with natural gas as a fuel.

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