Title: Experimental study on heat transfer in heavy oil reservoirs during in-situ combustion

Authors: Jiuzhi Sun; Yunjie Shu; Yi Pan; Yanchao Wang; Juan Huang; Zhaoxuan Li

Addresses: Department of Petroleum Engineering, Liaoning Petrochemical University, 1 Western Dandong Road, Fushun, 113001, Liaoning, China ' PetroChina Sichuan Marketing Company, No. 18 Middle Section, First Ring Road, Chengdu, 610000, Sichuan, China ' Department of Petroleum Engineering, Liaoning Petrochemical University, 1 Western Dandong Road, Fushun, 113001, Liaoning, China ' Department of Petroleum Engineering, Liaoning Petrochemical University, 1 Western Dandong Road, Fushun, 113001, Liaoning, China ' Shuguang Oil Production Plant, PetroChina Liaohe Oilfield, No. 88 Shuguang Road, Panjin, 124010, Liaoning, China ' Department of Petroleum Engineering, Liaoning Petrochemical University, 1 Western Dandong Road, Fushun, 113001, Liaoning, China

Abstract: Heavy oil and extra-heavy oil, characterised by their high viscosity, extraction difficulties, and low oil recovery, critically require efficient extraction methodologies. The in-situ combustion (ISC) technique offers a promising solution by injecting air into the reservoir to ignite heavy oil, using heat to improve recovery; however, its intricate mechanisms necessitate further optimisation. This study established an indoor simulation platform to investigate the effects of ignition temperature, porosity, gas injection rate, and injection duration on heat transfer. The experimental results showed that ignition temperature, porosity, and gas injection rate have significant effects on the oxidation and combustion of heavy oil. At 240°C, the combustion front struggled to propagate, while at 280°C, it stabilised with peak temperatures above 400°C. Increasing porosity promoted temperature rise, and the combustion front propagated optimally at a gas injection rate of 1,600 mL/min. However, at 1,800 mL/min, combustion became too intense, hindering front propagation. Extending the reaction time increased the propagation distance, but due to the limitation of reservoir fuel, continuous propagation was not possible. This study provided significant experimental and theoretical guidance for further exploration and optimisation of the ISC technique, contributing to the enhancement of unconventional energy extraction. [Received: November 8, 2024; Accepted: April 4, 2025]

Keywords: heavy oil; in-situ combustion; combustion property; enhanced oil recovery; reservoir heat transfer.

DOI: 10.1504/IJOGCT.2026.153018

International Journal of Oil, Gas and Coal Technology, 2026 Vol.39 No.3, pp.251 - 279

Received: 22 Oct 2024
Accepted: 04 Apr 2025
Published online: 20 Apr 2026 *

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