Dynamic optimization control of injection-production parameters for autothermic pyrolysis in-situ conversion process of oil shale
Abstract
The autothermic pyrolysis in-situ conversion process of oil shale has emerged as a vital development direction due to its advantages of environmental friendliness and low cost. However, previous studies predominantly employed constant injection and production parameters, which often result in inefficient compression energy injection and formation oxidation losses, thereby limiting further improvements in energy efficiency and oil production. To address these issues, this study establishes a dynamic optimization model for injection-production parameters in the autothermic pyrolysis in-situ conversion process of oil shale, developing a dynamic control methodology for gas injection rate and oxygen content to enhance the economic viability and feasibility of the process. The results indicate that under the optimal combination of gas injection– adjustment time, decay rate, and terminal flow rate– the steady-state phase during late production can significantly reduce input compression energy and inhibit hydrocarbon oxidation losses, ultimately leading to a substantial increase in the peak energy efficiency and cumulative oil production. Furthermore, by synergistically regulating oxygen content and injection rate during the early production stage, the compression energy can be further reduced, ultimately elevating the energy efficiency to approximately fourteen, demonstrating the technical feasibility for industrial-scale production. These findings and the identified key parameters provide crucial theoretical and technical support for the large-scale application of the autothermic pyrolysis in-situ conversion technology for oil shale.
Document Type: Original article
Cited as: Zhu, C., He, C., Wu, J., Guo, W. Dynamic optimization control of injection-production parameters for autothermic pyrolysis in-situ conversion process of oil shale. Advances in Geo-Energy Research, 2026, 20(2): 129-144. https://doi.org/10.46690/ager.2026.05.03
DOI:
https://doi.org/10.46690/ager.2026.05.03Keywords:
Oil shale, autothermic pyrolysis, injection-production parameters, numerical simulation, dynamic regulationReferences
Alshareef, A. H., Scherer, A., Tan, X., et al. Formation of archipelago structures during thermal cracking implicates a chemical mechanism for the formation of petroleum asphaltenes. Energy & Fuels, 2011, 25: 2130.
Brandt, A. R. Converting oil shale to liquid fuels: Energy inputs and greenhouse gas emissions of the Shell in situ conversion process. Environmental Science & Technology, 2008, 42(19): 7489-7495.
Braun, R. L., Burnham, A. K. PMOD: a flexible model of oil and gas generation, cracking, and expulsion. Organic Geochemistry, 1992, 19(1): 161-172.
Dong, F., Feng, Z., Yang, D., et al. Permeability evolution of pyrolytically-fractured oil shale under in situ conditions. Energies, 2018, 11(11): 3033.
Du, M., Yang, Z., Feng, C., et al. Microscopic production characteristics of pore crude oil and influencing factors during enhanced oil recovery by air injection in shale oil reservoirs. ACS Omega, 2023, 8(20): 18186-18201.
Fan, D. Research on paleoclimate, paleoenvironment and source rock development model of the cretaceous Shahezi Formation in Xujiaweizi fault depression, Songliao Basin. Changchun, Jilin University, 2022. (in Chinese)
Gao, Y., Wan, T., Dong, Y., et al. Numerical and experimental investigation of production performance of in-situ conversion of shale oil by air injection. Energy Reports, 2022, 8: 1099-1112.
Guo, W., Li, Q., Deng, S., et al. Mechanism and reservoir simulation study of the autothermic pyrolysis in-situ conversion process for oil shale recovery. Petroleum Science, 2023a, 20(2): 1053-1067.
Guo, W., Sun, Y., Li, Q., et al. Oil shale in-situ conversion technology triggered by topochemical reaction method and pilot test project in Songliao Basin. Acta Petrolei Sinica, 2024, 45(7): 1104-1121+1129. (in Chinese)
Guo, W., Yang, Q., Deng, S., et al. Experimental study of the autothermic pyrolysis in-situ conversion process (ATS) for oil shale recovery. Energy, 2022, 258: 124878.
Guo, W., Zhang, X., Sun, Y., et al. Migration mechanism of pyrolysis oil during oil shale in situ pyrolysis exploitation. Energy, 2023b, 285: 128769.
He, H., Liu, Y., Zhao, G., et al. Investigation of in situ gelation behavior and enhanced oil recovery ability of polymer gel used for controlling CO2 channeling in tight fractured reservoir. Gels, 2024, 10(11): 741.
He, W., Sun, Y., Guo, W., et al. Organic geochemical characteristics of the upper cretaceous Qingshankou Formation oil shales in the Fuyu Oilfield, Songliao Basin, China: Implications for oil-generation potential and depositional environment. Energies, 2019, 12(24): 4778.
He, W., Sun, Y., Shan, X. Organic matter evolution in pyrolysis experiments of oil shale under high pressure: Guidance for in situ conversion of oil shale in the Songliao Basin. Journal of Analytical and Applied Pyrolysis, 2021, 155: 105091.
Jia, B., Huang, Z. Oil shale in situ production using a novel flow-heat coupling approach. ACS Omega, 2024, 9(7): 7705-7718.
Jin, J., Deng, Y., Song, L., et al. Nanozeolite encapsulated single-atom catalysts: Synergetic in-situ conversion of oil shale using supercritical CO2. SPE Journal, 2025, 30(8): 4814-4824.
Jin, J., Song, C., Sun, J., et al. ZnCl2-catalyzed low-temperature pyrolysis enabling efficient upgrading of Wangqing oil shale. Fuel, 2026, 420: 138926.
Khakimova, L., Bondarenko, T., Cheremisin, A., et al. High pressure air injection kinetic model for Bazhenov Shale Formation based on a set of oxidation studies. Journal of Petroleum Science and Engineering, 2019, 172: 11201132.
Lee, K. J., Finsterle, S., Moridis, G. J. Analyzing the impact of reaction models on the production of hydrocarbons from thermally upgraded oil shales. Journal of Petroleum Science and Engineering, 2018, 168: 448-464.
Li, J., Lang, Y., Li, B., et al. N2 influences on CH4 accumulation and displacement in shale by molecular dynamics. Scientific Reports, 2025a, 15(1): 1833.
Li, Q., Wang, X., Li, D., et al. Development and performance evaluation of multi-functional slickwater fracturing fluid system for shale reservoirs. Scientific Reports, 2025b, 15(1): 17637.
Liu, Y., Xue, L., Bai, F., et al. Three-dimensional numerical simulation of hydrocarbon production and reservoir deformation of oil shale in situ conversion processing using a downhole burner. ACS Omega, 2022, 7(27): 23695-23707.
Lu, Y., Wang, Z., Kang, Z., et al. Comparative study on the pyrolysis behavior and pyrolysate characteristics of Fushun oil shale during anhydrous pyrolysis and sub/supercritical water pyrolysis. RSC Advances, 2022, 12(26): 16329-16341.
Ma, C., Tan, F., Qin, J., et al. Study on the difference in CO2 and air injection in the fracture/matrix dual medium of continental shale reservoirs. ACS Omega, 2023, 8(22): 20020-20030.
Pei, S., Wang, Y., Zhang, L., et al. An innovative nitrogen injection assisted in-situ conversion process for oil shale recovery: Mechanism and reservoir simulation study. Journal of Petroleum Science and Engineering, 2018, 171: 507-515.
Shakib, J. T., Akhgarian, E., Ghaderi, A. The effect of hydraulic fracture characteristics on production rate in thermal EOR methods. Fuel, 2015, 141: 226-235.
Sun, W., Liu, X., Zhan, T., et al. Quality characteristics of oil shale of the 1st member of upper cretaceous Qingshankou Formation of well JFD3 in southeastern rising area of Songliao Basin. Jilin Geology, 2022, 41(2): 18-23. (in Chinese)
Tian, H., Guo, W., Li, Q., et al. High-pressure pyrolysis mechanism of tar-rich coal in Taiyuan Formation, Ordos Basin. Energy, 2025, 337: 138675.
Tong, J., Han, X., Wang, S., et al. Evaluation of structural characteristics of Huadian oil shale kerogen using direct techniques (Solid-State 13C NMR, XPS, FT-IR, and XRD). Energy & Fuels, 2011, 25(9): 4006-4013.
Wang, E., Guo, T., Li, M. Paleosedimentary environmental reconstruction and mechanisms of the response to the Toarcian OAE in a lacustrine shale system. Scientific Reports, 2024a, 14(1): 14082.
Wang, G., Yang, D., Zhao, Y., et al. Experimental investigation on anisotropic permeability and its relationship with anisotropic thermal cracking of oil shale under high temperature and triaxial stress. Applied Thermal Engineering, 2019, 146: 718-725.
Wang, L., Gao, C., Xiong, R., et al. Development review and the prospect of oil shale in-situ catalysis conversion technology. Petroleum Science, 2024b, 21(2): 1385-1395.
Wang, L., Yang, D., Zhao, Y., et al. Evolution of pore characteristics in oil shale during pyrolysis under convection and conduction heating modes. Oil Shale, 2020, 37(3): 224-241.
Wang, W. Establishment and application of evaluation criteria of shale oil and gas resources potential: A case of southern Songliao Basin. Daqing, Northeast Petroleum University, 2013. (in Chinese)
Wang, Y., Ren, S., Zhang, L., et al. Numerical study of air assisted cyclic steam stimulation process for heavy oil reservoirs: Recovery performance and energy efficiency analysis. Fuel, 2018, 211: 471-483.
Wang, Y., Kang, S., Jiao, L., et al. Catalytic hydrothermal pyrolysis behaviors of oil shale under restrained conditions. Scientific Reports, 2025, 15(1): 21276.
Wu, A., Wu, J., Chen, L., et al. Recent progress on in situ catalytic conversion catalysts for oil shale. ACS Omega, 2024, 9(35): 36904-36916.
Xie, X., Hu, L., Deng, H., et al. Evolution of pore structure and fractal characteristics of marine shale during electromagnetic radiation. Plos One, 2020, 15(10): e0239662.
Xu, S., Lü, X., Sun, Y., et al. Optimization of temperature parameters for the autothermic pyrolysis in-situ conversion process of oil shale. Energy, 2023, 264: 126309.
Yang, F., Cheng, X., Li, M., et al. Numerical investigation of the heat and mass transfer during the in situ pyrolysis process of oil-rich coal. Processes, 2023a, 11(11): 3226.
Yang, Q., Guo, W., Xu, S., et al. The autothermic pyrolysis in-situ conversion process for oil shale recovery: Effect of gas injection parameters. Energy, 2023b, 283: 129134.
Yan, Z., Ji, H., Guo, G., et al. Geochemical characteristics of trace elements and REEs and their geological significance for uranium mineralization within the Qianjiadian sandstone-hosted uranium deposit, Songliao Basin. Geofluids, 2023, 2023: 6297033.
Zhang, L., Chen, L., Hu, R., et al. Subsurface multiphase reactive flow in geologic CO2 storage: Key impact factors and characterization approaches. Advances in Geo-Energy Research, 2022, 6(3): 179-180.
Zhao, F., Yang, Z., Zhang, L., et al. The effect of temperature on pyrolysis products during oil shale thermal decomposition. Scientific Reports, 2025, 15(1): 26135.
Zhao, R., Xu, H., Sun, Z., et al. Study on the lower limits of physical parameters for heavy oil reservoirs during the in situ combustion process. ACS Omega, 2023, 8(6): 5995-6008.
Zhou, X., Li, H., Zeng, F., et al. Lightening of shale oil using high-temperature supercritical CO2: An experimental study. Advances in Geo-Energy Research, 2025, 16(2): 99-113.
Zhu, C., Guo, W., Sun, Y., et al. Reaction mechanism and reservoir simulation study of the high-temperature nitrogen injection in-situ oil shale process: A case study in Songliao Basin, China. Fuel, 2022, 316: 123164.
Zhu, C., Jiang, T., Yao, S., et al. Numerical investigation of natural gas-enhanced autothermic pyrolysis for optimizing in-situ conversion in oil shale. Petroleum Science, 2026, 23(2): 762-776.
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Copyright (c) 2026 Chaofan Zhu, Cheng He, Jiyue Wu, Wei Guo
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