In this paper a simulation model of oil shale formation is generated in which the reservoir is heated by downhole heaters and subsurface solid kerogen is converted into liquid and gas hydrocarbons by the function of chemical reactions, temperature and time. On the basis of the results obtained, the alteration in porosity and permeability is evaluated. It is found that the porosity and permeability of oil shale increase significantly as a function of in-situ kerogen conversion into oil and gas. A new mathematical modeling approach is adopted to measure the quantitative change in porosity. It is revealed that the effective porosity of the studied reservoir increases from the initial value of 5% to the final value of 12.5% after in-situ kerogen pyrolysis. In-situ permeability, as a function of porosity, is also modeled and a noteworthy increase is observed. The results are compared with previously published experimental findings and are found to be in a good agreement.
1. Demirbas, A. Conversion of oil shale to liquid hydrocarbons. Energ. Source. Part A, 2016, 38(18), 2698‒2703.
2. Xu, Y., Sun, P., Yao, S., Liu, Z., Tian, X., Li, F., Zhang, J. Progress in exploration, development and utilization of oil shale in China. Oil Shale, 2019, 36(2), 285‒304.
3. Dyni, J. R. Geology and Resources of Some World Oil-Shale Deposits. Scientific Investigations Report 2005-5294. US Geological Survey, Reston, Virginia, USA, 2006.
4. El-Mofty, S. E., Khairy, N., El-Kammar, A. M., El-Midany, A. A. Effect of mineralogical composition and kerogen content on oil shale natural floatability. Energ. Source. Part A, 2018, 40(9), 1144‒1152.
5. Fan, Y., Durlofsky, L. J., Tchelepi, H. A. Numerical simulation of the in-situ upgrading of oil shale. SPE J., 2010, 15(2), 368–381.
6. Zafar, A., Su, Y. L., Wang, W. D., Alam, S. G., Khan, D., Yasir, M., Alrassas, A., Ahmad, I. Heat dissipation modeling of in-situ conversion of oil shale. Open Journal of Yangtze Gas and Oil, 2020, 5(2), 46‒53.
7. Zafar, A., Su, Y., Li, L., Mehmood, A., Wang, H., Fu, J. The numerical simulation and wellbore modelling of steam injection and stored heat recovery from light oil reservoir. Energ. Source. Part A, 2019.
8. Zafar, A., Su, Y., Wang, W., Li, L., Alam, S. G., Mehmood, A., Tahir, M. U., Fu, J. The Numerical Simulation of Effects of Porosity, Permeability and Fluid Saturation on Heat Dissipation in an Oil Reservoir. 2nd Conference of the Arabian Journal of Geosciences (CAJG), 25‒28 November 2019, Sousse, Tunisia.
9. Wang, W., Fan, D., Sheng, G., Chen, Z., Su, Y. A review of analytical and semi-analytical fluid flow models for ultra-tight hydrocarbon reservoirs. Fuel, 2019, 256, 115737.
10. Zafar, A., Su, Y.-L., Li, L., Fu, J.-G., Mehmood, A., Ouyang, W.-P., Zhang, M. Tight gas production model considering TPG as a function of pore pressure, permeability and water saturation. Pet. Sci., 2020, 17, 1356‒1369.
11. Zafar, A., Fan, H. J. Combination of geological, geophysical and reservoir engineering analyses in field development: a case study. International Journal of Environmental, Chemical, Ecological, Geological and Geophysical Engineering, 2017, 11(1), 36‒43.
12. Fan, H. J., Zafar, A., Alam, S. G., Kashif, M., Mehmood, A. Analyses of nature of fault through production data. Open Journal of Yangtze Gas and Oil, 2017, 2(3), 176‒190.
13. Wang, H., Su, Y., Wang, W., Sheng, G., Li, H., Zafar, A. Enhanced water flow and apparent viscosity model considering wettability and shape effects. Fuel, 2019, 253, 1351‒1360.
14. Lee, K. J. Rigorous Simulation Model of Kerogen Pyrolysis for the In-situ Upgrading of Oil Shales. PhD Dissertation, Texas A&M University, College Station, Texas, 2014.
15. Hazra, K. G., Lee, K. J., Economides, C. E., Moridis, G. Comparison of Heating Methods for In-Situ Oil Shale Extraction. 17th European Symposium on Improved Oil Recovery, From Fundamental Science to Deployment, 16–18 April 2013, Saint Petersburg, Russia.
16. Bauman, J. H., Deo, M. D. Parameter space reduction and sensitivity analysis in complex thermal subsurface production processes. Energ. Fuel., 2011,25(1), 251–259.
17. Shen, C. Reservoir Simulation Study of an In-Situ Conversion Pilot of Green-River Oil Shale. SPE Rocky Mountain Petroleum Technology Conference, 14–16 April 2009, Denver, Colorado.
18. Brandt, A. R. Converting oil shale to liquid fuels: energy inputs and greenhouse gas emissions of the Shell in situ conversion process. Environ. Sci. Technol., 2008, 42(19), 7489–7495.
19. Youtsos, M. S. K., Mastorakos, E., Cant, R. S. Numerical simulation of thermal and reaction fronts for oil shale upgrading. Chem. Eng. Sci., 2013, 94, 200–213.
20. Jupp, T. E., Woods, A. W. Thermally driven reaction fronts in porous media. J. Fluid Mech., 2003, 484, 329–346.
21. White, M., Chick, L., McVay, G. Impact of Geothermic Well Temperatures and Residence Time on the In-Situ Production of Hydrocarbon Gases from Green River Formation Oil Shale. 30th Oil Shale Symposium, Colorado School of Mines, Colorado Energy Research Institute, Golden, Colorado, USA, 18‒20 October 2010, Presentation 7–1.
22. Bai, F., Sun, Y., Liu, Y., Guo, M. Evaluation of the porous structure of Huadian oil shale during pyrolysis using multiple approaches. Fuel, 2017, 187, 1–8.
23. Han, J., Sun, Y., Guo, W., Li, Q., Deng, S. Characterization of pyrolysis of Nong’an oil shale at different temperatures and analysis of pyrolysate. Oil Shale,36(2S), 151‒170.
24. Jia, J., Qian, R., He, J. Achieving resilience and sustainability through innovative design for oil shale pyrolysis process model. Oil Shale, 2019, 36(2S), 142‒150.
25. Liu, J., Liang, W., Kang, Z., Lian, H., Geng, Y. Study on the quantitative model of oil shale porosity in the pyrolysis process based on pyrolysis kinetics. Oil Shale, 2018, 35(2), 128‒143.
26. Wang, L., Yang, D., Zhao, J., Zhao, Y., Kang, Z. Changes in oil shale characteristics during simulated in-situ pyrolysis in superheated steam. Oil Shale, 2018, 35(3), 230‒241.
27. Kang, Z. The Pyrolysis Characteristics and In-Situ Hot Drive Simulation Research That Exploit Oil-Gas of Oil Shale. PhD Thesis, Taiyuan University of Technology, 2008 (in Chinese with English abstract).
28. Zhao, J. Experimental Study on the Microscopic Characteristics and Mechanical Property of Oil Shale under High Temperature & Three-Dimensional Stress. PhD Thesis, Taiyuan University of Technology, 2014 (in Chinese with English abstract).