CALCULATION OF COMPRESSIBILITY FACTOR OF MAIN NATURAL GAS COMPONENTS BY MEANS OF MOLECULAR DYNAMICS SIMULATIONS
| Autor: | Victor L. Malyshev, Elena F. Moiseeva, Yurii V. Kalinovsky |
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| Jazyk: | ruština |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Известия Томского политехнического университета: Инжиниринг георесурсов, Vol 330, Iss 11, Pp 121-129 (2019) |
| Druh dokumentu: | article |
| ISSN: | 24131830 2500-1019 2413-1830 |
| DOI: | 10.18799/24131830/2019/11/2356 |
| Popis: | The relevance of the work is caused by the need to determine the exact value of the compressibility factor for calculating gas reserves, forecasting technological indicators for development of gas and gas condensate fields, the behavior of hydrocarbon systems flow in wells, and preparation of well production and its transportation. The aim of the research is to develop a program for computation of the compressibility factor for the main components of natural gas to achieve more accuracy in determining z-factor in comparison with classical approach, based on the equations of state. Methods. To determine the z-factor the authors have used the technique based on the Peng–Robinson equation of state, its modification with a shift parameter, and a software module for molecular dynamic simulation developed by the authors that describes the behavior of the system at the molecular level. The potential of Lennard-Jones and NPT-ensemble is considered as a model of interatomic interaction of particles. Results. Based on the proposed methods of modeling, it was shown that the molecular dynamics simulations make it possible to accurately calculate the compressibility factor for the main components of natural gases. Based of the Peng–Robinson equation of state and its modification with a shift parameter, as well as using the molecular dynamics simulation for methane, ethane, propane, nitrogen and carbon dioxide, the dependencies of the compressibility factor on pressure were determined in the temperature range from 250 to 410 K. Lennard-Jones potential parameters for ethane, propane, nitrogen and carbon dioxide were specified that made it possible to improve the accuracy in calculating the compressibility factor. It is shown that the average absolute error of the molecular dynamics method in almost all calculations does not exceed 3 %. |
| Databáze: | Directory of Open Access Journals |
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