Thermo-chemical heavy oil development: multi-reaction coupled heat generation & recovery enhancement

raditional heavy oil thermal recovery methods, which rely on steam from conventional boilers as the heat transfer medium, suffer from limitations such as low recovery efficiency due to rapid reservoir water breakthrough and poor thermal utilization. To address these issues, this study introduces an innovative Chemical Reaction-based Enhanced Oil Recovery (CHEOR) technology. It directly heats reservoirs through exothermic directional chemical reactions, generating in situ heat in porous media via catalytic reactions and thus avoiding the constraints of conventional steam injection. A comprehensive framework integrating theoretical modeling and multi-scale experimental validation, including one-dimensional and three-dimensional physical simulation experiments, was developed to evaluate the technology. Key findings are as follows: Firstly, under current catalytic conditions, the Fischer-Tropsch reaction requires an oil-free and water-free environment. Secondly, laboratory experiments showed significant thermal enhancement, with the temperature in porous media increasing by 167℃ at a gas injection rate of 1000 mL/min. Thirdly, chemical reaction byproducts effectively promoted the propagation of the thermal front, increasing the temperature field sweep efficiency by 7 % compared to conventional Steam-Assisted Gravity Drainage (SAGD). Finally, the CHEOR-SAGD hybrid approach achieved a recovery rate of 74.13 %, which is 17.58 % higher than standalone SAGD operations. In addition, this technology offers dual environmental benefits, reducing water consumption by 43 % and carbon emissions by 28 % compared to conventional thermal methods. These experimental validations provide critical technical parameters for field-scale implementation and highlight the potential of CHEOR as a sustainable alternative for heavy oil exploitation.